;;; ange-ftp.el --- transparent FTP support for GNU Emacs

;; Copyright (C) 1989,90,91,92,93,94,95,96,98  Free Software Foundation, Inc.

;; Author: Andy Norman (ange@hplb.hpl.hp.com)
;; Maintainer: FSF
;; Keywords: comm

;; This file is part of GNU Emacs.

;; GNU Emacs is free software; you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation; either version 2, or (at your option)
;; any later version.

;; GNU Emacs is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;; GNU General Public License for more details.

;; You should have received a copy of the GNU General Public License
;; along with GNU Emacs; see the file COPYING.  If not, write to the
;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
;; Boston, MA 02111-1307, USA.

;;; Commentary:

;; This package attempts to make accessing files and directories using FTP
;; from within GNU Emacs as simple and transparent as possible.  A subset of
;; the common file-handling routines are extended to interact with FTP.

;; Usage:
;;
;; Some of the common GNU Emacs file-handling operations have been made
;; FTP-smart.  If one of these routines is given a filename that matches
;; '/user@host:name' then it will spawn an FTP process connecting to machine
;; 'host' as account 'user' and perform its operation on the file 'name'.
;;
;; For example: if find-file is given a filename of:
;;
;;   /ange@anorman:/tmp/notes
;;
;; then ange-ftp spawns an FTP process, connect to the host 'anorman' as
;; user 'ange', get the file '/tmp/notes' and pop up a buffer containing the
;; contents of that file as if it were on the local filesystem.  If ange-ftp
;; needs a password to connect then it reads one in the echo area.

;; Extended filename syntax:
;;
;; The default extended filename syntax is '/user@host:name', where the
;; 'user@' part may be omitted.  This syntax can be customised to a certain
;; extent by changing ange-ftp-name-format.  There are limitations.
;;
;; If the user part is omitted then ange-ftp generates a default user
;; instead whose value depends on the variable ange-ftp-default-user.

;; Passwords:
;;
;; A password is required for each host/user pair.  Ange-ftp reads passwords
;; as needed.  You can also specify a password with ange-ftp-set-passwd, or
;; in a *valid* ~/.netrc file.

;; Passwords for user "anonymous":
;;
;; Passwords for the user "anonymous" (or "ftp") are handled
;; specially.  The variable `ange-ftp-generate-anonymous-password'
;; controls what happens: if the value of this variable is a string,
;; then this is used as the password; if non-nil (the default), then
;; the value of `user-mail-address' is used; if nil then the user
;; is prompted for a password as normal.

;; "Dumb" UNIX hosts:
;;
;; The FTP servers on some UNIX machines have problems if the 'ls' command is
;; used.
;;
;; The routine ange-ftp-add-dumb-unix-host can be called to tell ange-ftp to
;; limit itself to the DIR command and not 'ls' for a given UNIX host.  Note
;; that this change will take effect for the current GNU Emacs session only.
;; See below for a discussion of non-UNIX hosts.  If a large number of
;; machines with similar hostnames have this problem then it is easier to set
;; the value of ange-ftp-dumb-unix-host-regexp in your .emacs file. ange-ftp
;; is unable to automatically recognize dumb unix hosts.

;; File name completion:
;;
;; Full file-name completion is supported on UNIX, VMS, CMS, and MTS hosts.
;; To do filename completion, ange-ftp needs a listing from the remote host.
;; Therefore, for very slow connections, it might not save any time.

;; FTP processes:
;;
;; When ange-ftp starts up an FTP process, it leaves it running for speed
;; purposes.  Some FTP servers will close the connection after a period of
;; time, but ange-ftp should be able to quietly reconnect the next time that
;; the process is needed.
;;
;; Killing the "*ftp user@host*" buffer also kills the ftp process.
;; This should not cause ange-ftp any grief.

;; Binary file transfers:
;;
;; By default ange-ftp transfers files in ASCII mode.  If a file being
;; transferred matches the value of ange-ftp-binary-file-name-regexp then
;; binary mode is used for that transfer.

;; Account passwords:
;;
;; Some FTP servers require an additional password which is sent by the
;; ACCOUNT command.  ange-ftp partially supports this by allowing the user to
;; specify an account password by either calling ange-ftp-set-account, or by
;; specifying an account token in the .netrc file.  If the account password
;; is set by either of these methods then ange-ftp will issue an ACCOUNT
;; command upon starting the FTP process.

;; Preloading:
;;
;; ange-ftp can be preloaded, but must be put in the site-init.el file and
;; not the site-load.el file in order for the documentation strings for the
;; functions being overloaded to be available.

;; Status reports:
;;
;; Most ange-ftp commands that talk to the FTP process output a status
;; message on what they are doing.  In addition, ange-ftp can take advantage
;; of the FTP client's HASH command to display the status of transferring
;; files and listing directories.  See the documentation for the variables
;; ange-ftp-{ascii,binary}-hash-mark-size, ange-ftp-send-hash and
;; ange-ftp-process-verbose for more details.

;; Gateways:
;;
;; Sometimes it is necessary for the FTP process to be run on a different
;; machine than the machine running GNU Emacs.  This can happen when the
;; local machine has restrictions on what hosts it can access.
;;
;; ange-ftp has support for running the ftp process on a different (gateway)
;; machine.  The way it works is as follows:
;;
;; 1) Set the variable 'ange-ftp-gateway-host' to the name of a machine
;;    that doesn't have the access restrictions.
;;
;; 2) Set the variable 'ange-ftp-local-host-regexp' to a regular expression
;;    that matches hosts that can be contacted from running a local ftp
;;    process, but fails to match hosts that can't be accessed locally.  For
;;    example:
;;
;;    "\\.hp\\.com$\\|^[^.]*$"
;;
;;    will match all hosts that are in the .hp.com domain, or don't have an
;;    explicit domain in their name, but will fail to match hosts with
;;    explicit domains or that are specified by their ip address.
;;
;; 3) Using NFS and symlinks, make sure that there is a shared directory with
;;    the *same* name between the local machine and the gateway machine.
;;    This directory is necessary for temporary files created by ange-ftp.
;;
;; 4) Set the variable 'ange-ftp-gateway-tmp-name-template' to the name of
;;    this directory plus an identifying filename prefix.  For example:
;;
;;    "/nfs/hplose/ange/ange-ftp"
;;
;;    where /nfs/hplose/ange is a directory that is shared between the
;;    gateway machine and the local machine.
;;
;; The simplest way of getting a ftp process running on the gateway machine
;; is if you can spawn a remote shell using either 'rsh' or 'remsh'.  If you
;; can't do this for some reason such as security then points 7 onwards will
;; discuss an alternative approach.
;;
;; 5) Set the variable ange-ftp-gateway-program to the name of the remote
;;    shell process such as 'remsh' or 'rsh' if the default isn't correct.
;;
;; 6) Set the variable ange-ftp-gateway-program-interactive to nil if it
;;    isn't already.  This tells ange-ftp that you are using a remote shell
;;    rather than logging in using telnet or rlogin.
;;
;; That should be all you need to allow ange-ftp to spawn a ftp process on
;; the gateway machine.  If you have to use telnet or rlogin to get to the
;; gateway machine then follow the instructions below.
;;
;; 7) Set the variable ange-ftp-gateway-program to the name of the program
;;    that lets you log onto the gateway machine.  This may be something like
;;    telnet or rlogin.
;;
;; 8) Set the variable ange-ftp-gateway-prompt-pattern to a regular
;;    expression that matches the prompt you get when you login to the
;;    gateway machine.  Be very specific here; this regexp must not match
;;    *anything* in your login banner except this prompt.
;;    shell-prompt-pattern is far too general as it appears to match some
;;    login banners from Sun machines.  For example:
;;
;;    "^$*$ *"
;;
;; 9) Set the variable ange-ftp-gateway-program-interactive to 't' to let
;;    ange-ftp know that it has to "hand-hold" the login to the gateway
;;    machine.
;;
;; 10) Set the variable ange-ftp-gateway-setup-term-command to a UNIX command
;;     that will put the pty connected to the gateway machine into a
;;     no-echoing mode, and will strip off carriage-returns from output from
;;     the gateway machine.  For example:
;;
;;     "stty -onlcr -echo"
;;
;;     will work on HP-UX machines, whereas:
;;
;;     "stty -echo nl"
;;
;;     appears to work for some Sun machines.
;;
;; That's all there is to it.

;; Smart gateways:
;;
;; If you have a "smart" ftp program that allows you to issue commands like
;; "USER foo@bar" which do nice proxy things, then look at the variables
;; ange-ftp-smart-gateway and ange-ftp-smart-gateway-port.
;;
;; Otherwise, if there is an alternate ftp program that implements proxy in
;; a transparent way (i.e. w/o specifying the proxy host), that will
;; connect you directly to the desired destination host:
;; Set ange-ftp-gateway-ftp-program-name to that program's name.
;; Set ange-ftp-local-host-regexp to a value as stated earlier on.
;; Leave ange-ftp-gateway-host set to nil.
;; Set ange-ftp-smart-gateway to t.

;; Tips for using ange-ftp:
;;
;; 1. For dired to work on a host which marks symlinks with a trailing @ in
;;    an ls -alF listing, you need to (setq dired-ls-F-marks-symlinks t).
;;    Most UNIX systems do not do this, but ULTRIX does. If you think that
;;    there is a chance you might connect to an ULTRIX machine (such as
;;    prep.ai.mit.edu), then set this variable accordingly.  This will have
;;    the side effect that dired will have problems with symlinks whose names
;;    end in an @.  If you get yourself into this situation then editing
;;    dired's ls-switches to remove "F", will temporarily fix things.
;;
;; 2. If you know that you are connecting to a certain non-UNIX machine
;;    frequently, and ange-ftp seems to be unable to guess its host-type,
;;    then setting the appropriate host-type regexp
;;    (ange-ftp-vms-host-regexp, ange-ftp-mts-host-regexp, or
;;    ange-ftp-cms-host-regexp) accordingly should help. Also, please report
;;    ange-ftp's inability to recognize the host-type as a bug.
;;
;; 3. For slow connections, you might get "listing unreadable" error
;;    messages, or get an empty buffer for a file that you know has something
;;    in it. The solution is to increase the value of ange-ftp-retry-time.
;;    Its default value is 5 which is plenty for reasonable connections.
;;    However, for some transatlantic connections I set this to 20.
;;
;; 4. Beware of compressing files on non-UNIX hosts. Ange-ftp will do it by
;;    copying the file to the local machine, compressing it there, and then
;;    sending it back. Binary file transfers between machines of different
;;    architectures can be a risky business. Test things out first on some
;;    test files. See "Bugs" below. Also, note that ange-ftp copies files by
;;    moving them through the local machine. Again, be careful when doing
;;    this with binary files on non-Unix machines.
;;
;; 5. Beware that dired over ftp will use your setting of dired-no-confirm
;;    (list of dired commands for which confirmation is not asked).  You
;;    might want to reconsider your setting of this variable, because you
;;    might want confirmation for more commands on remote direds than on
;;    local direds. For example, I strongly recommend that you not include
;;    compress and uncompress in this list. If there is enough demand it
;;    might be a good idea to have an alist ange-ftp-dired-no-confirm of
;;    pairs ( TYPE . LIST ), where TYPE is an operating system type and LIST
;;    is a list of commands for which confirmation would be suppressed.  Then
;;    remote dired listings would take their (buffer-local) value of
;;    dired-no-confirm from this alist. Who votes for this?

;; ---------------------------------------------------------------------
;; Non-UNIX support:
;; ---------------------------------------------------------------------

;; VMS support:
;;
;; Ange-ftp has full support for VMS hosts.  It
;; should be able to automatically recognize any VMS machine. However, if it
;; fails to do this, you can use the command ange-ftp-add-vms-host.  As well,
;; you can set the variable ange-ftp-vms-host-regexp in your .emacs file. We
;; would be grateful if you would report any failures to automatically
;; recognize a VMS host as a bug.
;;
;; Filename Syntax:
;;
;; For ease of *implementation*, the user enters the VMS filename syntax in a
;; UNIX-y way.  For example:
;;  PUB$:[ANONYMOUS.SDSCPUB.NEXT]README.TXT;1
;; would be entered as:
;;  /PUB$$:/ANONYMOUS/SDSCPUB/NEXT/README.TXT;1
;; i.e. to log in as anonymous on ymir.claremont.edu and grab the file:
;;  [.CSV.POLICY]RULES.MEM
;; you would type:
;;  C-x C-f /anonymous@ymir.claremont.edu:CSV/POLICY/RULES.MEM
;;
;; A legal VMS filename is of the form: FILE.TYPE;##
;; where FILE can be up to 39 characters
;;       TYPE can be up to 39 characters
;;       ## is a version number (an integer between 1 and 32,767)
;; Valid characters in FILE and TYPE are A-Z 0-9 _ - $
;; $ cannot begin a filename, and - cannot be used as the first or last
;; character.
;;
;; Tips:
;; 1. Although VMS is not case sensitive, EMACS running under UNIX is.
;;    Therefore, to access a VMS file, you must enter the filename with upper
;;    case letters.
;; 2. To access the latest version of file under VMS, you use the filename
;;    without the ";" and version number. You should always edit the latest
;;    version of a file. If you want to edit an earlier version, copy it to a
;;    new file first. This has nothing to do with ange-ftp, but is simply
;;    good VMS operating practice. Therefore, to edit FILE.TXT;3 (say 3 is
;;    latest version), do C-x C-f /ymir.claremont.edu:FILE.TXT. If you
;;    inadvertently do C-x C-f /ymir.claremont.edu:FILE.TXT;3, you will find
;;    that VMS will not allow you to save the file because it will refuse to
;;    overwrite FILE.TXT;3, but instead will want to create FILE.TXT;4, and
;;    attach the buffer to this file. To get out of this situation, M-x
;;    write-file /ymir.claremont.edu:FILE.TXT will attach the buffer to
;;    latest version of the file. For this reason, in dired "f"
;;    (dired-find-file), always loads the file sans version, whereas "v",
;;    (dired-view-file), always loads the explicit version number. The
;;    reasoning being that it reasonable to view old versions of a file, but
;;    not to edit them.
;; 3. EMACS has a feature in which it does environment variable substitution
;;    in filenames. Therefore, to enter a $ in a filename, you must quote it
;;    by typing $$.

;; MTS support:
;;
;; Ange-ftp has full support for hosts running
;; the Michigan terminal system.  It should be able to automatically
;; recognize any MTS machine. However, if it fails to do this, you can use
;; the command ange-ftp-add-mts-host.  As well, you can set the variable
;; ange-ftp-mts-host-regexp in your .emacs file. We would be grateful if you
;; would report any failures to automatically recognize a MTS host as a bug.
;;
;; Filename syntax:
;; 
;; MTS filenames are entered in a UNIX-y way. For example, if your account
;; was YYYY, the file FILE in the account XXXX: on mtsg.ubc.ca would be
;; entered as
;;   /YYYY@mtsg.ubc.ca:/XXXX:/FILE
;; In other words, MTS accounts are treated as UNIX directories. Of course,
;; to access a file in another account, you must have access permission for
;; it.  If FILE were in your own account, then you could enter it in a
;; relative name fashion as
;;   /YYYY@mtsg.ubc.ca:FILE
;; MTS filenames can be up to 12 characters. Like UNIX, the structure of the
;; filename does not contain a TYPE (i.e. it can have as many "."'s as you
;; like.) MTS filenames are always in upper case, and hence be sure to enter
;; them as such! MTS is not case sensitive, but an EMACS running under UNIX
;; is.

;; CMS support:
;; 
;; Ange-ftp has full support for hosts running
;; CMS.  It should be able to automatically recognize any CMS machine.
;; However, if it fails to do this, you can use the command
;; ange-ftp-add-cms-host.  As well, you can set the variable
;; ange-ftp-cms-host-regexp in your .emacs file. We would be grateful if you
;; would report any failures to automatically recognize a CMS host as a bug.
;; 
;; Filename syntax:
;;
;; CMS filenames are entered in a UNIX-y way. In otherwords, minidisks are
;; treated as UNIX directories. For example to access the file READ.ME in
;; minidisk *.311 on cuvmb.cc.columbia.edu, you would enter
;;   /anonymous@cuvmb.cc.columbia.edu:/*.311/READ.ME
;; If *.301 is the default minidisk for this account, you could access
;; FOO.BAR on this minidisk as
;;   /anonymous@cuvmb.cc.columbia.edu:FOO.BAR
;; CMS filenames are of the form FILE.TYPE, where both FILE and TYPE can be
;; up to 8 characters. Again, beware that CMS filenames are always upper
;; case, and hence must be entered as such.
;;
;; Tips:
;; 1. CMS machines, with the exception of anonymous accounts, nearly always
;;    need an account password. To have ange-ftp send an account password,
;;    you can either include it in your .netrc file, or use
;;    ange-ftp-set-account.
;; 2. Ange-ftp cannot send "write passwords" for a minidisk. Hopefully, we
;;    can fix this.
;;
;; ------------------------------------------------------------------
;; Bugs:
;; ------------------------------------------------------------------
;; 
;; 1. Umask problems:
;;    Be warned that files created by using ange-ftp will take account of the
;;    umask of the ftp daemon process rather than the umask of the creating
;;    user.  This is particularly important when logging in as the root user.
;;    The way that I tighten up the ftp daemon's umask under HP-UX is to make
;;    sure that the umask is changed to 027 before I spawn /etc/inetd.  I
;;    suspect that there is something similar on other systems.
;;
;; 2. Some combinations of FTP clients and servers break and get out of sync
;;    when asked to list a non-existent directory.  Some of the ai.mit.edu
;;    machines cause this problem for some FTP clients. Using
;;    ange-ftp-kill-ftp-process can restart the ftp process, which
;;    should get things back in sync.
;;
;; 3. Ange-ftp does not check to make sure that when creating a new file,
;;    you provide a valid filename for the remote operating system.
;;    If you do not, then the remote FTP server will most likely
;;    translate your filename in some way. This may cause ange-ftp to
;;    get confused about what exactly is the name of the file. The
;;    most common causes of this are using lower case filenames on systems
;;    which support only upper case, and using filenames which are too
;;    long.
;;
;; 4. Null (blank) passwords confuse both ange-ftp and some FTP daemons.
;;
;; 5. Ange-ftp likes to use pty's to talk to its FTP processes.  If GNU Emacs
;;    for some reason creates a FTP process that only talks via pipes then
;;    ange-ftp won't be getting the information it requires at the time that
;;    it wants it since pipes flush at different times to pty's.  One
;;    disgusting way around this problem is to talk to the FTP process via
;;    rlogin which does the 'right' things with pty's.
;;
;; 6. For CMS support, we send too many cd's. Since cd's are cheap, I haven't
;;    worried about this too much. Eventually, we should have some caching
;;    of the current minidisk.
;;    
;; 7. Some CMS machines do not assign a default minidisk when you ftp them as
;;    anonymous. It is then necessary to guess a valid minidisk name, and cd
;;    to it. This is (understandably) beyond ange-ftp.
;;
;; 8. Remote to remote copying of files on non-Unix machines can be risky.
;;    Depending on the variable ange-ftp-binary-file-name-regexp, ange-ftp
;;    will use binary mode for the copy. Between systems of different
;;    architecture, this still may not be enough to guarantee the integrity
;;    of binary files. Binary file transfers from VMS machines are
;;    particularly problematical. Should ange-ftp-binary-file-name-regexp be
;;    an alist of OS type, regexp pairs?
;;
;; 9. The code to do compression of files over ftp is not as careful as it
;;    should be. It deletes the old remote version of the file, before
;;    actually checking if the local to remote transfer of the compressed
;;    file succeeds. Of course to delete the original version of the file
;;    after transferring the compressed version back is also dangerous,
;;    because some OS's have severe restrictions on the length of filenames,
;;    and when the compressed version is copied back the "-Z" or ".Z" may be
;;    truncated. Then, ange-ftp would delete the only remaining version of
;;    the file.  Maybe ange-ftp should make backups when it compresses files
;;    (of course, the backup "~" could also be truncated off, sigh...).
;;    Suggestions?
;;
;; 10. If a dir listing is attempted for an empty directory on (at least
;;     some) VMS hosts, an ftp error is given. This is really an ftp bug, and
;;     I don't know how to get ange-ftp work to around it.
;;
;; 11. Bombs on filenames that start with a space. Deals well with filenames
;;     containing spaces, but beware that the remote ftpd may not like them
;;     much.
;;
;; 12. The dired support for non-Unix-like systems does not currently work.
;;     It needs to be reimplemented by modifying the parse-...-listing
;;	functions to convert the directory listing to ls -l format.
;; 
;; 13. The famous @ bug. As mentioned above in TIPS, ULTRIX marks symlinks
;;     with a trailing @ in a ls -alF listing. In order to account for this
;;     ange-ftp looks to chop trailing @'s off of symlink names when it is
;;     parsing a listing with the F switch. This will cause ange-ftp to
;;     incorrectly get the name of a symlink on a non-ULTRIX host if its name
;;     ends in an @. ange-ftp will correct itself if you take F out of the
;;     dired ls switches (C-u s will allow you to edit the switches). The
;;     dired buffer will be automatically reverted, which will allow ange-ftp
;;     to fix its files hashtable.  A cookie to anyone who can think of a
;;     fast, sure-fire way to recognize ULTRIX over ftp.

;; If you find any bugs or problems with this package, PLEASE either e-mail
;; the above author, or send a message to the ange-ftp-lovers mailing list
;; below.  Ideas and constructive comments are especially welcome.

;; ange-ftp-lovers:
;;
;; ange-ftp has its own mailing list modestly called ange-ftp-lovers.  All
;; users of ange-ftp are welcome to subscribe (see below) and to discuss
;; aspects of ange-ftp.  New versions of ange-ftp are posted periodically to
;; the mailing list.
;;
;; To [un]subscribe to ange-ftp-lovers, or to report mailer problems with the
;; list, please mail one of the following addresses:
;;
;;     ange-ftp-lovers-request@anorman.hpl.hp.com
;; or
;;     ange-ftp-lovers-request%anorman.hpl.hp.com@hplb.hpl.hp.com
;;
;; Please don't forget the -request part.
;;
;; For mail to be posted directly to ange-ftp-lovers, send to one of the
;; following addresses:
;; 
;;     ange-ftp-lovers@anorman.hpl.hp.com
;; or
;;     ange-ftp-lovers%anorman.hpl.hp.com@hplb.hpl.hp.com
;;
;; Alternatively, there is a mailing list that only gets announcements of new
;; ange-ftp releases.  This is called ange-ftp-lovers-announce, and can be
;; subscribed to by e-mailing to the -request address as above.  Please make
;; it clear in the request which mailing list you wish to join.

;; The latest version of ange-ftp can usually be obtained via anonymous ftp
;; from:
;;     alpha.gnu.ai.mit.edu:ange-ftp/ange-ftp.tar.Z
;; or:
;;     ugle.unit.no:/pub/gnu/emacs-lisp/ange-ftp.tar.Z
;; or:
;;   archive.cis.ohio-state.edu:pub/gnu/emacs/elisp-archive/packages/ange-ftp.tar.Z

;; The archives for ange-ftp-lovers can be found via anonymous ftp under:
;;
;;     ftp.reed.edu:pub/mailing-lists/ange-ftp/

;; -----------------------------------------------------------
;; Technical information on this package:
;; -----------------------------------------------------------

;; ange-ftp works by putting a handler on file-name-handler-alist
;; which is called by many primitives, and a few non-primitives,
;; whenever they see a file name of the appropriate sort.

;; Checklist for adding non-UNIX support for TYPE
;; 
;; The following functions may need TYPE versions:
;; (not all functions will be needed for every OS)
;;
;; ange-ftp-fix-name-for-TYPE
;; ange-ftp-fix-dir-name-for-TYPE
;; ange-ftp-TYPE-host
;; ange-ftp-TYPE-add-host
;; ange-ftp-parse-TYPE-listing
;; ange-ftp-TYPE-delete-file-entry
;; ange-ftp-TYPE-add-file-entry
;; ange-ftp-TYPE-file-name-as-directory
;; ange-ftp-TYPE-make-compressed-filename
;; ange-ftp-TYPE-file-name-sans-versions
;;
;; Variables:
;;
;; ange-ftp-TYPE-host-regexp
;; May need to add TYPE to ange-ftp-dumb-host-types
;;
;; Check the following functions for OS dependent coding:
;;
;; ange-ftp-host-type
;; ange-ftp-guess-host-type
;; ange-ftp-allow-child-lookup

;; Host type conventions:
;;
;; The function ange-ftp-host-type and the variable ange-ftp-dired-host-type
;; (mostly) follow the following conventions for remote host types.  At
;; least, I think that future code should try to follow these conventions,
;; and the current code should eventually be made compliant.
;;
;; nil = local host type, whatever that is (probably unix).
;;       Think nil as in "not a remote host". This value is used by
;;       ange-ftp-dired-host-type for local buffers.
;;
;; t = a remote host of unknown type. Think t as in true, it's remote.
;;     Currently, `unix' is used as the default remote host type.
;;     Maybe we should use t.
;;
;; TYPE = a remote host of TYPE type.
;;
;; TYPE:LIST = a remote host of TYPE type, using a specialized ftp listing
;;             program called list. This is currently only used for Unix
;;             dl (descriptive listings), when ange-ftp-dired-host-type
;;             is set to `unix:dl'.

;; Bug report codes:
;;
;; Because of their naive faith in this code, there are certain situations
;; which the writers of this program believe could never happen. However,
;; being realists they have put calls to `error' in the program at these
;; points. These errors provide a code, which is an integer, greater than 1.
;; To aid debugging.  the error codes, and the functions in which they reside
;; are listed below.
;; 
;; 1: See ange-ftp-ls
;;

;; -----------------------------------------------------------
;; Hall of fame:
;; -----------------------------------------------------------
;; 
;; Thanks to Roland McGrath for improving the filename syntax handling,
;; for suggesting many enhancements and for numerous cleanups to the code.
;;
;; Thanks to Jamie Zawinski for bugfixes and for ideas such as gateways.
;;
;; Thanks to Ken Laprade for improved .netrc parsing, password reading, and
;; dired / shell auto-loading.
;;
;; Thanks to Sebastian Kremer for dired support and for many ideas and
;; bugfixes.
;;
;; Thanks to Joe Wells for bugfixes, the original non-UNIX system support,
;; VOS support, and hostname completion.
;;
;; Thanks to Nakagawa Takayuki for many good ideas, filename-completion, help
;; with file-name expansion, efficiency worries, stylistic concerns and many
;; bugfixes.
;;
;; Thanks to Sandy Rutherford who re-wrote most of ange-ftp to support VMS,
;; MTS, CMS and UNIX-dls.  Sandy also added dired-support for non-UNIX OS and
;; auto-recognition of the host type.
;;
;; Thanks to Dave Smith who wrote the info file for ange-ftp.
;;
;; Finally, thanks to Keith Waclena, Mark D. Baushke, Terence Kelleher, Ping
;; Zhou, Edward Vielmetti, Jack Repenning, Mike Balenger, Todd Kaufmann,
;; Kjetil Svarstad, Tom Wurgler, Linus Tolke, Niko Makila, Carl Edman, Bill
;; Trost, Dave Brennan, Dan Jacobson, Andy Scott, Steve Anderson, Sanjay
;; Mathur, the folks on the ange-ftp-lovers mailing list and many others
;; whose names I've forgotten who have helped to debug and fix problems with
;; ange-ftp.el.

;;; Code:

(require 'comint)
;; Silence compiler:
(eval-when-compile
  (defvar comint-last-output-start nil)
  (defvar comint-last-input-start nil)
  (defvar comint-last-input-end nil))

;;;; ------------------------------------------------------------
;;;; User customization variables.
;;;; ------------------------------------------------------------

(defgroup ange-ftp nil
  "Accessing remote files and directories using FTP 
   made as simple and transparent as possible."
  :group 'files
  :prefix "ange-ftp-")

(defcustom ange-ftp-name-format
  '("^/\\(\\([^@/:]*\\)@\\)?\\([^@/:]*[^@/:.]\\):\\(.*\\)" . (3 2 4))
  "*Format of a fully expanded remote file name.

This is a list of the form \(REGEXP HOST USER NAME\),
where REGEXP is a regular expression matching
the full remote name, and HOST, USER, and NAME are the numbers of
parenthesized expressions in REGEXP for the components (in that order)."
  :group 'ange-ftp
  :type '(list regexp 
	       (integer :tag "Host group")
	       (integer :tag "User group")
	       (integer :tag "Name group")))

;; ange-ftp-multi-skip-msgs should only match ###-, where ### is one of
;; the number codes corresponding to ange-ftp-good-msgs or ange-ftp-fatal-msgs.
;; Otherwise, ange-ftp will go into multi-skip mode, and never come out.

(defvar ange-ftp-multi-msgs
  "^220-\\|^230-\\|^226\\|^25.-\\|^221-\\|^200-\\|^331-\\|^4[25]1-\\|^530-"
  "*Regular expression matching the start of a multiline ftp reply.")

(defvar ange-ftp-good-msgs
  "^220 \\|^230 \\|^226 \\|^25. \\|^221 \\|^200 \\|^[Hh]ash mark"
  "*Regular expression matching ftp \"success\" messages.")

;; CMS and the odd VMS machine say 200 Port rather than 200 PORT.
;; Also CMS machines use a multiline 550- reply to say that you
;; don't have write permission. ange-ftp gets into multi-line skip
;; mode and hangs. Have it ignore 550- instead. It will then barf
;; when it gets the 550 line, as it should.

;; RFC2228 "FTP Security Extensions" defines extensions to the FTP
;; protocol which involve the client requesting particular
;; authentication methods (typically) at connection establishment. Non
;; security-aware FTP servers should respond to this with a 500 code,
;; which we ignore.
(defcustom ange-ftp-skip-msgs
  (concat "^200 \\(PORT\\|Port\\) \\|^331 \\|^150 \\|^350 \\|^[0-9]+ bytes \\|"
	  "^Connected \\|^$\\|^Remote system\\|^Using\\|^ \\|Password:\\|"
	  "^Data connection \\|"
	  "^local:\\|^Trying\\|^125 \\|^550-\\|^221 .*oodbye\\|"
          "^500 .*AUTH \\(KERBEROS\\|GSSAPI\\)\\|^KERBEROS\\|"
	  "^227 .*[Pp]assive")
  "*Regular expression matching ftp messages that can be ignored."
  :group 'ange-ftp
  :type 'regexp)

(defcustom ange-ftp-fatal-msgs
  (concat "^ftp: \\|^Not connected\\|^530 \\|^4[25]1 \\|rcmd: \\|"
	  "^No control connection\\|unknown host\\|^lost connection")
  "*Regular expression matching ftp messages that indicate serious errors.

These mean that the FTP process should (or already has) been killed."
  :group 'ange-ftp
  :type 'regexp)

(defcustom ange-ftp-gateway-fatal-msgs
  "No route to host\\|Connection closed\\|No such host\\|Login incorrect"
  "*Regular expression matching login failure messages from rlogin/telnet."
  :group 'ange-ftp
  :type 'regexp)

(defcustom ange-ftp-xfer-size-msgs
  "^150 .* connection for .* (\\([0-9]+\\) bytes)"
  "*Regular expression used to determine the number of bytes in a FTP transfer."
  :group 'ange-ftp
  :type 'regexp)

(defcustom ange-ftp-tmp-name-template 
  (expand-file-name "ange-ftp" temporary-file-directory)
  "*Template used to create temporary files."
  :group 'ange-ftp
  :type 'directory)

(defcustom ange-ftp-gateway-tmp-name-template "/tmp/ange-ftp"
  "*Template used to create temporary files when ftp-ing through a gateway.

Files starting with this prefix need to be accessible from BOTH the local
machine and the gateway machine, and need to have the SAME name on both
machines, that is, /tmp is probably NOT what you want, since that is rarely
cross-mounted."
  :group 'ange-ftp
  :type 'directory)

(defcustom ange-ftp-netrc-filename "~/.netrc"
  "*File in .netrc format to search for passwords."
  :group 'ange-ftp
  :type 'file)

(defcustom ange-ftp-disable-netrc-security-check (eq system-type 'windows-nt)
  "*If non-nil avoid checking permissions on the .netrc file."
  :group 'ange-ftp
  :type 'boolean)

(defcustom ange-ftp-default-user nil
  "*User name to use when none is specified in a file name.

If non-nil but not a string, you are prompted for the name.
If nil, the value of `ange-ftp-netrc-default-user' is used.
If that is nil too, then your login name is used.

Once a connection to a given host has been initiated, the user name
and password information for that host are cached and re-used by
ange-ftp.  Use \\[ange-ftp-set-user] to change the cached values,
since setting `ange-ftp-default-user' directly does not affect
the cached information."
  :group 'ange-ftp
  :type '(choice (const :tag "Default" nil)
		 string
		 (other :tag "Prompt" t)))

(defcustom ange-ftp-netrc-default-user nil
  "Alternate default user name to use when none is specified.

This variable is set from the `default' command in your `.netrc' file,
if there is one."
  :group 'ange-ftp
  :type '(choice (const :tag "Default" nil)
		 string))

(defcustom ange-ftp-default-password nil
  "*Password to use when the user name equals `ange-ftp-default-user'."
  :group 'ange-ftp
  :type '(choice (const :tag "Default" nil)
		 string))

(defcustom ange-ftp-default-account nil
  "*Account to use when the user name equals `ange-ftp-default-user'."
  :group 'ange-ftp
  :type '(choice (const :tag "Default" nil)
		 string))

(defcustom ange-ftp-netrc-default-password nil
  "*Password to use when the user name equals `ange-ftp-netrc-default-user'."
  :group 'ange-ftp
  :type '(choice (const :tag "Default" nil)
		 string))

(defcustom ange-ftp-netrc-default-account nil
  "*Account to use when the user name equals `ange-ftp-netrc-default-user'."
  :group 'ange-ftp
  :type '(choice (const :tag "Default" nil)
		 string))

(defcustom ange-ftp-generate-anonymous-password t
  "*If t, use value of `user-mail-address' as password for anonymous ftp.

If a string, then use that string as the password.
If nil, prompt the user for a password."
  :group 'ange-ftp
  :type '(choice (const :tag "Prompt" nil)
		 string
		 (other :tag "User address" t)))

(defcustom ange-ftp-dumb-unix-host-regexp nil
  "*If non-nil, regexp matching hosts on which `dir' command lists directory."
  :group 'ange-ftp
  :type '(choice (const :tag "Default" nil)
		 string))

(defcustom ange-ftp-binary-file-name-regexp
  (concat "\\.[zZ]$\\|\\.lzh$\\|\\.arc$\\|\\.zip$\\|\\.zoo$\\|\\.tar$\\|"
	  "\\.dvi$\\|\\.ps$\\|\\.elc$\\|TAGS$\\|\\.gif$\\|"
	  "\\.EXE\\(;[0-9]+\\)?$\\|\\.[zZ]-part-..$\\|\\.gz$\\|"
	  "\\.taz$\\|\\.tgz$")
  "*If a file matches this regexp then it is transferred in binary mode."
  :group 'ange-ftp
  :type 'regexp)

(defcustom ange-ftp-gateway-host nil
  "*Name of host to use as gateway machine when local FTP isn't possible."
  :group 'ange-ftp
  :type '(choice (const :tag "Default" nil)
		 string))

(defcustom ange-ftp-local-host-regexp ".*"
  "*Regexp selecting hosts which can be reached directly with ftp.

For other hosts the FTP process is started on \`ange-ftp-gateway-host\'
instead, and/or reached via \`ange-ftp-gateway-ftp-program-name\'."
  :group 'ange-ftp
  :type 'regexp)

(defcustom ange-ftp-gateway-program-interactive nil
  "*If non-nil then the gateway program should  give a shell prompt.

Both telnet and rlogin do something like this."
  :group 'ange-ftp
  :type 'boolean)

(defcustom ange-ftp-gateway-program remote-shell-program
  "*Name of program to spawn a shell on the gateway machine.

Valid candidates are rsh (remsh on some systems), telnet and rlogin.  See
also the gateway variable above."
  :group 'ange-ftp
  :type '(choice (const "rsh")
		 (const "telnet")
		 (const "rlogin")
		 string))

(defcustom ange-ftp-gateway-prompt-pattern "^[^#$%>;\n]*[#$%>;] *"
  "*Regexp matching prompt after complete login sequence on gateway machine.

A match for this means the shell is now awaiting input.  Make this regexp as
strict as possible; it shouldn't match *anything* at all except the user's
initial prompt.  The above string will fail under most SUN-3's since it
matches the login banner."
  :group 'ange-ftp
  :type 'regexp)

(defvar ange-ftp-gateway-setup-term-command
  (if (eq system-type 'hpux)
      "stty -onlcr -echo\n"
    "stty -echo nl\n")
  "*Set up terminal after logging in to the gateway machine.
This command should stop the terminal from echoing each command, and
arrange to strip out trailing ^M characters.")

(defcustom ange-ftp-smart-gateway nil
  "*Non-nil means the ftp gateway and/or the gateway ftp program is smart.

Don't bother telnetting, etc., already connected to desired host transparently,
or just issue a user@host command in case \`ange-ftp-gateway-host\' is non-nil."
  :group 'ange-ftp
  :type 'boolean)

(defcustom ange-ftp-smart-gateway-port "21"
  "*Port on gateway machine to use when smart gateway is in operation."
  :group 'ange-ftp
  :type 'string)

(defcustom ange-ftp-send-hash t
  "*If non-nil, send the HASH command to the FTP client."
  :group 'ange-ftp
  :type 'boolean)

(defcustom ange-ftp-binary-hash-mark-size nil
  "*Default size, in bytes, between hash-marks when transferring a binary file.
If nil, this variable will be locally overridden if the FTP client outputs a
suitable response to the HASH command.  If non-nil, this value takes
precedence over the local value."
  :group 'ange-ftp
  :type '(choice (const :tag "Overridden" nil)
		 integer))

(defcustom ange-ftp-ascii-hash-mark-size 1024
  "*Default size, in bytes, between hash-marks when transferring an ASCII file.
This variable is buffer-local and will be locally overridden if the FTP client
outputs a suitable response to the HASH command."
  :group 'ange-ftp
  :type 'integer)

(defcustom ange-ftp-process-verbose t
  "*If non-nil then be chatty about interaction with the FTP process."
  :group 'ange-ftp
  :type 'boolean)

(defcustom ange-ftp-ftp-program-name "ftp"
  "*Name of FTP program to run."
  :group 'ange-ftp
  :type 'string)

(defcustom ange-ftp-gateway-ftp-program-name "ftp"
  "*Name of FTP program to run when accessing non-local hosts.

Some AT&T folks claim to use something called `pftp' here."
  :group 'ange-ftp
  :type 'string)

(defcustom ange-ftp-ftp-program-args '("-i" "-n" "-g" "-v")
  "*A list of arguments passed to the FTP program when started."
  :group 'ange-ftp
  :type '(repeat string))

(defcustom ange-ftp-nslookup-program nil
  "*If non-nil, this is a string naming the nslookup program." 
  :group 'ange-ftp
  :type '(choice (const :tag "None" nil)
		 string))

(defcustom ange-ftp-make-backup-files ()
  "*Non-nil means make backup files for \"magic\" remote files."
  :group 'ange-ftp
  :type 'boolean)

(defcustom ange-ftp-retry-time 5
  "*Number of seconds to wait before retry if file or listing doesn't arrive.
This might need to be increased for very slow connections."
  :group 'ange-ftp
  :type 'integer)

(defcustom ange-ftp-auto-save 0
  "If 1, allow ange-ftp files to be auto-saved.
If 0, inhibit auto-saving of ange-ftp files.
Don't use any other value."
  :group 'ange-ftp
  :type '(choice (const :tag "Suppress" 0)
		 (const :tag "Allow" 1)))

;;;; ------------------------------------------------------------
;;;; Hash table support.
;;;; ------------------------------------------------------------

(require 'backquote)

(defun ange-ftp-make-hashtable (&optional size)
  "Make an obarray suitable for use as a hashtable.
SIZE, if supplied, should be a prime number."
  (make-vector (or size 31) 0))

(defun ange-ftp-map-hashtable (fun tbl)
  "Call FUNCTION on each key and value in HASHTABLE."
  (mapatoms
   (function 
    (lambda (sym)
      (funcall fun (get sym 'key) (get sym 'val))))
   tbl))

(defmacro ange-ftp-make-hash-key (key)
  "Convert KEY into a suitable key for a hashtable."
  (` (if (stringp (, key))
	 (, key)
       (prin1-to-string (, key)))))

(defun ange-ftp-get-hash-entry (key tbl)
  "Return the value associated with KEY in HASHTABLE."
  (let ((sym (intern-soft (ange-ftp-make-hash-key key) tbl)))
    (and sym (get sym 'val))))

(defun ange-ftp-put-hash-entry (key val tbl)
  "Record an association between KEY and VALUE in HASHTABLE."
  (let ((sym (intern (ange-ftp-make-hash-key key) tbl)))
    (put sym 'val val)
    (put sym 'key key)))

(defun ange-ftp-del-hash-entry (key tbl)
  "Copy all symbols except KEY in HASHTABLE and return modified hashtable."
  (let* ((len (length tbl))
	 (new-tbl (ange-ftp-make-hashtable len))
	 (i (1- len)))
    (ange-ftp-map-hashtable
     (function
      (lambda (k v)
	(or (equal k key)
	    (ange-ftp-put-hash-entry k v new-tbl))))
     tbl)
    (while (>= i 0)
      (aset tbl i (aref new-tbl i))
      (setq i (1- i)))
    tbl))

(defun ange-ftp-hash-entry-exists-p (key tbl)
  "Return whether there is an association for KEY in TABLE."
  (intern-soft (ange-ftp-make-hash-key key) tbl))

(defun ange-ftp-hash-table-keys (tbl)
  "Return a sorted list of all the active keys in TABLE, as strings."
  (sort (all-completions "" tbl)
	(function string-lessp)))

;;;; ------------------------------------------------------------
;;;; Internal variables.
;;;; ------------------------------------------------------------

(defvar ange-ftp-data-buffer-name " *ftp data*"
  "Buffer name to hold directory listing data received from ftp process.")

(defvar ange-ftp-netrc-modtime nil
  "Last modified time of the netrc file from file-attributes.")

(defvar ange-ftp-user-hashtable (ange-ftp-make-hashtable)
  "Hash table holding associations between HOST, USER pairs.")

(defvar ange-ftp-passwd-hashtable (ange-ftp-make-hashtable)
  "Mapping between a HOST, USER pair and a PASSWORD for them.
All HOST values should be in lower case.")

(defvar ange-ftp-account-hashtable (ange-ftp-make-hashtable)
  "Mapping between a HOST, USER pair and a ACCOUNT password for them.")

(defvar ange-ftp-files-hashtable (ange-ftp-make-hashtable 97)
  "Hash table for storing directories and their respective files.")

(defvar ange-ftp-inodes-hashtable (ange-ftp-make-hashtable 97)
  "Hash table for storing file names and their \"inode numbers\".")

(defvar ange-ftp-next-inode-number 1
  "Next \"inode number\" value.  We give each file name a unique number.")

(defvar ange-ftp-ls-cache-lsargs nil
  "Last set of args used by ange-ftp-ls.")

(defvar ange-ftp-ls-cache-file nil
  "Last file passed to ange-ftp-ls.")

(defvar ange-ftp-ls-cache-res nil
  "Last result returned from ange-ftp-ls.")

(defconst ange-ftp-expand-dir-hashtable (ange-ftp-make-hashtable))

(defconst ange-ftp-expand-dir-regexp "^5.0 \\([^: ]+\\):")

;; These are local variables in each FTP process buffer.
(defvar ange-ftp-hash-mark-unit nil)
(defvar ange-ftp-hash-mark-count nil)
(defvar ange-ftp-xfer-size nil)
(defvar ange-ftp-process-string nil)
(defvar ange-ftp-process-result-line nil)
(defvar ange-ftp-process-busy nil)
(defvar ange-ftp-process-result nil)
(defvar ange-ftp-process-multi-skip nil)
(defvar ange-ftp-process-msg nil)
(defvar ange-ftp-process-continue nil)
(defvar ange-ftp-last-percent nil)

;; These variables are bound by one function and examined by another.
;; Leave them void globally for error checking.
(defvar ange-ftp-this-file)
(defvar ange-ftp-this-dir)
(defvar ange-ftp-this-user)
(defvar ange-ftp-this-host)
(defvar ange-ftp-this-msg)
(defvar ange-ftp-completion-ignored-pattern)
(defvar ange-ftp-trample-marker)

;; New error symbols.
(put 'ftp-error 'error-conditions '(ftp-error file-error error))
;; (put 'ftp-error 'error-message "FTP error")

;;; ------------------------------------------------------------
;;; Enhanced message support.
;;; ------------------------------------------------------------

(defun ange-ftp-message (fmt &rest args)
  "Display message in echo area, but indicate if truncated.
Args are as in `message': a format string, plus arguments to be formatted."
  (let ((msg (apply (function format) fmt args))
	(max (window-width (minibuffer-window))))
    (if noninteractive
	msg
      (if (>= (length msg) max)
	  ;; Take just the last MAX - 3 chars of the string.
	  (setq msg (concat "> " (substring msg (- 3 max)))))
      (message "%s" msg))))

(defun ange-ftp-abbreviate-filename (file &optional new)
  "Abbreviate the file name FILE relative to the default-directory.
If the optional parameter NEW is given and the non-directory parts match,
only return the directory part of FILE."
  (save-match-data
    (if (and default-directory
	     (string-match (concat "^"
				   (regexp-quote default-directory)
				   ".") file))
	(setq file (substring file (1- (match-end 0)))))
    (if (and new
	     (string-equal (file-name-nondirectory file)
			   (file-name-nondirectory new)))
	(setq file (file-name-directory file)))
    (or file "./")))

;;;; ------------------------------------------------------------
;;;; User / Host mapping support.
;;;; ------------------------------------------------------------

(defun ange-ftp-set-user (host user)
  "For a given HOST, set or change the default USER."
  (interactive "sHost: \nsUser: ")
  (ange-ftp-put-hash-entry host user ange-ftp-user-hashtable))

(defun ange-ftp-get-user (host)
  "Given a HOST, return the default USER."
  (ange-ftp-parse-netrc)
  (let ((user (ange-ftp-get-hash-entry host ange-ftp-user-hashtable)))
    (or user
	(prog1
	    (setq user
		  (cond ((stringp ange-ftp-default-user)
			 ;; We have a default name.  Use it.
			 ange-ftp-default-user)
			(ange-ftp-default-user
			 ;; Ask the user.
			 (let ((enable-recursive-minibuffers t))
			   (read-string (format "User for %s: " host)
					(user-login-name))))
			(ange-ftp-netrc-default-user)
			;; Default to the user's login name.
			(t
			 (user-login-name))))
	  (ange-ftp-set-user host user)))))

;;;; ------------------------------------------------------------
;;;; Password support.
;;;; ------------------------------------------------------------

(defmacro ange-ftp-generate-passwd-key (host user)
  (` (concat (downcase (, host)) "/" (, user))))

(defmacro ange-ftp-lookup-passwd (host user)
  (` (ange-ftp-get-hash-entry (ange-ftp-generate-passwd-key (, host) (, user))
			      ange-ftp-passwd-hashtable)))

(defun ange-ftp-set-passwd (host user passwd)
  "For a given HOST and USER, set or change the associated PASSWORD."
  (interactive (list (read-string "Host: ")
		     (read-string "User: ")
		     (read-passwd "Password: ")))
  (ange-ftp-put-hash-entry (ange-ftp-generate-passwd-key host user)
			   passwd
			   ange-ftp-passwd-hashtable))

(defun ange-ftp-get-host-with-passwd (user)
  "Given a USER, return a host we know the password for."
  (ange-ftp-parse-netrc)
  (catch 'found-one
    (ange-ftp-map-hashtable
     (function (lambda (host val)
		 (if (ange-ftp-lookup-passwd host user)
		     (throw 'found-one host))))
     ange-ftp-user-hashtable)
    (save-match-data
      (ange-ftp-map-hashtable
       (function
	(lambda (key value)
	  (if (string-match "^[^/]*\\(/\\).*$" key)
	      (let ((host (substring key 0 (match-beginning 1))))
		(if (and (string-equal user (substring key (match-end 1)))
			 value)
		    (throw 'found-one host))))))
       ange-ftp-passwd-hashtable))
    nil))

(defun ange-ftp-get-passwd (host user)
  "Return the password for specified HOST and USER, asking user if necessary."
  (ange-ftp-parse-netrc)

  ;; look up password in the hash table first; user might have overridden the
  ;; defaults.
  (cond ((ange-ftp-lookup-passwd host user))
	
	;; See if default user and password set.
	((and (stringp ange-ftp-default-user)
	      ange-ftp-default-password
	      (string-equal user ange-ftp-default-user))
	 ange-ftp-default-password)
	
	;; See if default user and password set from .netrc file.
	((and (stringp ange-ftp-netrc-default-user)
	      ange-ftp-netrc-default-password
	      (string-equal user ange-ftp-netrc-default-user))
	 ange-ftp-netrc-default-password)
	
	;; anonymous ftp password is handled specially since there is an
	;; unwritten rule about how that is used on the Internet.
	((and (or (string-equal user "anonymous")
		  (string-equal user "ftp"))
	      ange-ftp-generate-anonymous-password)
	 (if (stringp ange-ftp-generate-anonymous-password)
	     ange-ftp-generate-anonymous-password
	   user-mail-address))
	
	;; see if same user has logged in to other hosts; if so then prompt
	;; with the password that was used there.
	(t
	 (let* ((other (ange-ftp-get-host-with-passwd user))
		(passwd (if other
			    
			    ;; found another machine with the same user.
			    ;; Try that account.
			    (read-passwd
			     (format "passwd for %s@%s (default same as %s@%s): "
				     user host user other)
			     nil
			     (ange-ftp-lookup-passwd other user))
			  
			  ;; I give up.  Ask the user for the password.
			  (read-passwd
			   (format "Password for %s@%s: " user host)))))
	   (ange-ftp-set-passwd host user passwd)
	   passwd))))

;;;; ------------------------------------------------------------
;;;; Account support
;;;; ------------------------------------------------------------

;; Account passwords must be either specified in the .netrc file, or set
;; manually by calling ange-ftp-set-account.  For the moment, ange-ftp doesn't
;; check to see whether the FTP process is actually prompting for an account
;; password.
 
(defun ange-ftp-set-account (host user account)
  "For a given HOST and USER, set or change the associated ACCOUNT password."
  (interactive (list (read-string "Host: ")
		     (read-string "User: ")
		     (read-passwd "Account password: ")))
  (ange-ftp-put-hash-entry (ange-ftp-generate-passwd-key host user)
			   account
			   ange-ftp-account-hashtable))

(defun ange-ftp-get-account (host user)
  "Given a HOST and USER, return the FTP account."
  (ange-ftp-parse-netrc)
  (or (ange-ftp-get-hash-entry (ange-ftp-generate-passwd-key host user)
			       ange-ftp-account-hashtable)
      (and (stringp ange-ftp-default-user)
	   (string-equal user ange-ftp-default-user)
	   ange-ftp-default-account)
      (and (stringp ange-ftp-netrc-default-user)
	   (string-equal user ange-ftp-netrc-default-user)
	   ange-ftp-netrc-default-account)))

;;;; ------------------------------------------------------------
;;;; ~/.netrc support
;;;; ------------------------------------------------------------

(defun ange-ftp-chase-symlinks (file)
  "Return the filename that FILE references, following all symbolic links."
  (let (temp)
    (while (setq temp (ange-ftp-real-file-symlink-p file))
      (setq file
	    (if (file-name-absolute-p temp)
		temp
	      (concat (file-name-directory file) temp)))))
  file)

;; Move along current line looking for the value of the TOKEN.
;; Valid separators between TOKEN and its value are commas and
;; whitespace.  Second arg LIMIT is a limit for the search.

(defun ange-ftp-parse-netrc-token (token limit)
  (if (search-forward token limit t)
      (let (beg)
	(skip-chars-forward ", \t\r\n" limit)
	(if (eq (following-char) ?\")	;quoted token value
	    (progn (forward-char 1)
		   (setq beg (point))
		   (skip-chars-forward "^\"" limit)
		   (forward-char 1)
		   (buffer-substring beg (1- (point))))
	  (setq beg (point))
	  (skip-chars-forward "^, \t\r\n" limit)
	  (buffer-substring beg (point))))))

;; Extract the values for the tokens `machine', `login',
;; `password' and `account' in the current buffer.  If successful,
;; record the information found.

(defun ange-ftp-parse-netrc-group ()
  (let ((start (point))
	(end (save-excursion
	       (if (looking-at "machine\\>")
		   ;; Skip `machine' and the machine name that follows.
		   (progn
		     (skip-chars-forward "^ \t\r\n")
		     (skip-chars-forward " \t\r\n")
		     (skip-chars-forward "^ \t\r\n"))
		 ;; Skip `default'.
		 (skip-chars-forward "^ \t\r\n"))
	       ;; Find start of the next `machine' or `default'
	       ;; or the end of the buffer.
	       (if (re-search-forward "machine\\>\\|default\\>" nil t)
		   (match-beginning 0)
		 (point-max))))
	machine login password account)
    (setq machine  (ange-ftp-parse-netrc-token "machine"  end)
	  login    (ange-ftp-parse-netrc-token "login"    end)
	  password (ange-ftp-parse-netrc-token "password" end)
	  account  (ange-ftp-parse-netrc-token "account"  end))
    (if (and machine login)
	;; found a `machine` token.
	(progn
	  (ange-ftp-set-user machine login)
	  (ange-ftp-set-passwd machine login password)
	  (and account
	       (ange-ftp-set-account machine login account)))
      (goto-char start)
      (if (search-forward "default" end t)
	  ;; found a `default' token
	  (progn
	    (setq login    (ange-ftp-parse-netrc-token "login"    end)
		  password (ange-ftp-parse-netrc-token "password" end)
		  account  (ange-ftp-parse-netrc-token "account"  end))
	    (and login
		 (setq ange-ftp-netrc-default-user login))
	    (and password
		 (setq ange-ftp-netrc-default-password password))
	    (and account
		 (setq ange-ftp-netrc-default-account account)))))
    (goto-char end)))

;; Read in ~/.netrc, if one exists.  If ~/.netrc file exists and has
;; the correct permissions then extract the \`machine\', \`login\',
;; \`password\' and \`account\' information from within.

(defun ange-ftp-parse-netrc ()
  ;; We set this before actually doing it to avoid the possibility
  ;; of an infinite loop if ange-ftp-netrc-filename is an FTP file.
  (interactive)
  (let (file attr)
    (let ((default-directory "/"))
      (setq file (ange-ftp-chase-symlinks
		  (ange-ftp-real-expand-file-name ange-ftp-netrc-filename)))
      (setq attr (ange-ftp-real-file-attributes file)))
    (if (and attr			; file exists.
	     (not (equal (nth 5 attr) ange-ftp-netrc-modtime)))	; file changed
	(save-match-data
	  (if (or ange-ftp-disable-netrc-security-check
		  (and (eq (nth 2 attr) (user-uid)) ; Same uids.
		       (string-match ".r..------" (nth 8 attr))))
	      (save-excursion
		;; we are cheating a bit here.  I'm trying to do the equivalent
		;; of find-file on the .netrc file, but then nuke it afterwards.
		;; with the bit of logic below we should be able to have
		;; encrypted .netrc files.
		(set-buffer (generate-new-buffer "*ftp-.netrc*"))
		(ange-ftp-real-insert-file-contents file)
		(setq buffer-file-name file)
		(setq default-directory (file-name-directory file))
		(normal-mode t)
		(mapcar 'funcall find-file-hooks)
		(setq buffer-file-name nil)
		(goto-char (point-min))
		(skip-chars-forward " \t\r\n")
		(while (not (eobp))
		  (ange-ftp-parse-netrc-group))
		(kill-buffer (current-buffer)))
	    (ange-ftp-message "%s either not owned by you or badly protected."
			      ange-ftp-netrc-filename)
	    (sit-for 1))
	  (setq ange-ftp-netrc-modtime (nth 5 attr))))))

;; Return a list of prefixes of the form 'user@host:' to be used when
;; completion is done in the root directory.

(defun ange-ftp-generate-root-prefixes ()
  (ange-ftp-parse-netrc)
  (save-match-data
    (let (res)
      (ange-ftp-map-hashtable
       (function
	(lambda (key value)
	  (if (string-match "^[^/]*\\(/\\).*$" key)
	      (let ((host (substring key 0 (match-beginning 1)))
		    (user (substring key (match-end 1))))
		(setq res (cons (list (concat user "@" host ":"))
				res))))))
       ange-ftp-passwd-hashtable)
      (ange-ftp-map-hashtable
       (function (lambda (host user)
		   (setq res (cons (list (concat host ":"))
				   res))))
       ange-ftp-user-hashtable)
      (or res (list nil)))))

;;;; ------------------------------------------------------------
;;;; Remote file name syntax support.
;;;; ------------------------------------------------------------

(defmacro ange-ftp-ftp-name-component (n ns name)
  "Extract the Nth ftp file name component from NS."
  (` (let ((elt (nth (, n) (, ns))))
       (if (match-beginning elt)
	   (substring (, name) (match-beginning elt) (match-end elt))))))

(defvar ange-ftp-ftp-name-arg "")
(defvar ange-ftp-ftp-name-res nil)

;; Parse NAME according to `ange-ftp-name-format' (which see).
;; Returns a list (HOST USER NAME), or nil if NAME does not match the format.
(defun ange-ftp-ftp-name (name)
  (if (string-equal name ange-ftp-ftp-name-arg)
      ange-ftp-ftp-name-res
    (setq ange-ftp-ftp-name-arg name
	  ange-ftp-ftp-name-res
	  (save-match-data
	    (if (posix-string-match (car ange-ftp-name-format) name)
		(let* ((ns (cdr ange-ftp-name-format))
		       (host (ange-ftp-ftp-name-component 0 ns name))
		       (user (ange-ftp-ftp-name-component 1 ns name))
		       (name (ange-ftp-ftp-name-component 2 ns name)))
		  (if (zerop (length user))
		      (setq user (ange-ftp-get-user host)))
		  (list host user name))
	      nil)))))

;; Take a FULLNAME that matches according to ange-ftp-name-format and
;; replace the name component with NAME.
(defun ange-ftp-replace-name-component (fullname name)
  (save-match-data
    (if (posix-string-match (car ange-ftp-name-format) fullname)
	(let* ((ns (cdr ange-ftp-name-format))
	       (elt (nth 2 ns)))
	  (concat (substring fullname 0 (match-beginning elt))
		  name
		  (substring fullname (match-end elt)))))))

;;;; ------------------------------------------------------------
;;;; Miscellaneous utils.
;;;; ------------------------------------------------------------

;; (setq ange-ftp-tmp-keymap (make-sparse-keymap))
;; (define-key ange-ftp-tmp-keymap "\C-m" 'exit-minibuffer)

(defun ange-ftp-repaint-minibuffer ()
  "Clear any existing minibuffer message; let the minibuffer contents show."
  (message nil))

;; Return the name of the buffer that collects output from the ftp process
;; connected to the given HOST and USER pair.
(defun ange-ftp-ftp-process-buffer (host user)
  (concat "*ftp " user "@" host "*"))

;; Display the last chunk of output from the ftp process for the given HOST
;; USER pair, and signal an error including MSG in the text.
(defun ange-ftp-error (host user msg)
  (let ((cur (selected-window))
	(pop-up-windows t))
    (pop-to-buffer
     (get-buffer-create
      (ange-ftp-ftp-process-buffer host user)))
    (goto-char (point-max))
    (select-window cur))
  (signal 'ftp-error (list (format "FTP Error: %s" msg))))

(defun ange-ftp-set-buffer-mode ()
  "Set correct modes for the current buffer if visiting a remote file."
  (if (and (stringp buffer-file-name)
	   (ange-ftp-ftp-name buffer-file-name))
      (auto-save-mode ange-ftp-auto-save)))

(defun ange-ftp-kill-ftp-process (&optional buffer)
  "Kill the FTP process associated with BUFFER (the current buffer, if nil).
If the BUFFER's visited filename or default-directory is an ftp filename
then kill the related ftp process."
  (interactive "bKill FTP process associated with buffer: ")
  (if (null buffer)
      (setq buffer (current-buffer))
    (setq buffer (get-buffer buffer)))
  (let ((file (or (buffer-file-name buffer)
		  (save-excursion (set-buffer buffer) default-directory))))
    (if file
	(let ((parsed (ange-ftp-ftp-name (expand-file-name file))))
	  (if parsed
	      (let ((host (nth 0 parsed))
		    (user (nth 1 parsed)))
		(kill-buffer (get-buffer (ange-ftp-ftp-process-buffer host user)))))))))

(defun ange-ftp-quote-string (string)
  "Quote any characters in STRING that may confuse the ftp process."
  (apply (function concat)
	 (mapcar (function
		  ;; This is said to be wrong; ftp is said to
		  ;; need quoting only for ", and that by doubling it.
		  ;; But experiment says this kind of quoting is correct
		  ;; when talking to ftp on GNU/Linux systems.
		   (lambda (char)
		     (if (or (<= char ? )
			     (> char ?\~)
		             (= char ?\")
			     (= char ?\\))
			 (vector ?\\ char)
		       (vector char))))
		 string)))

(defun ange-ftp-barf-if-not-directory (directory)
  (or (file-directory-p directory)
      (signal 'file-error
	      (list "Opening directory"
		    (if (file-exists-p directory)
			"not a directory"
		      "no such file or directory")
		    directory))))

;;;; ------------------------------------------------------------
;;;; FTP process filter support.
;;;; ------------------------------------------------------------

(defun ange-ftp-process-handle-line (line proc)
  "Look at the given LINE from the ftp process PROC.
Try to categorize it into one of four categories:
good, skip, fatal, or unknown."
  (cond ((string-match ange-ftp-xfer-size-msgs line)
	 (setq ange-ftp-xfer-size
	       (ash (string-to-int (substring line
					      (match-beginning 1)
					      (match-end 1)))
		    -10)))
	((string-match ange-ftp-skip-msgs line)
	 t)
	((string-match ange-ftp-good-msgs line)
	 (setq ange-ftp-process-busy nil
	       ange-ftp-process-result t
	       ange-ftp-process-result-line line))
	;; Check this before checking for errors.
	;; Otherwise the last line of these three seems to be an error:
	;; 230-see a significant impact from the move.  For those of you who can't
	;; 230-use DNS to resolve hostnames and get an error message like
	;; 230-"ftp.stsci.edu: unknown host", the new IP address will be...
	((string-match ange-ftp-multi-msgs line)
	 (setq ange-ftp-process-multi-skip t))
	((string-match ange-ftp-fatal-msgs line)
	 (delete-process proc)
	 (setq ange-ftp-process-busy nil
	       ange-ftp-process-result-line line))
	(ange-ftp-process-multi-skip
	 t)
	(t
	 (setq ange-ftp-process-busy nil
	       ange-ftp-process-result-line line))))

(defun ange-ftp-set-xfer-size (host user bytes)
  "Set the size of the next FTP transfer in bytes."
  (let ((proc (ange-ftp-get-process host user)))
    (if proc
	(let ((buf (process-buffer proc)))
	  (if buf
	      (save-excursion
		(set-buffer buf)
		(setq ange-ftp-xfer-size (ash bytes -10))))))))

(defun ange-ftp-process-handle-hash (str)
  "Remove hash marks from STRING and display count so far."
  (setq str (concat (substring str 0 (match-beginning 0))
		    (substring str (match-end 0)))
	ange-ftp-hash-mark-count (+ (- (match-end 0)
				       (match-beginning 0))
				    ange-ftp-hash-mark-count))
  (and ange-ftp-hash-mark-unit
       ange-ftp-process-msg
       ange-ftp-process-verbose
       (not (eq (selected-window) (minibuffer-window)))
       (not (boundp 'search-message))	;screws up isearch otherwise
       (not cursor-in-echo-area)	;screws up y-or-n-p otherwise
       (let ((kbytes (ash (* ange-ftp-hash-mark-unit
			     ange-ftp-hash-mark-count)
			  -6)))
       (if (zerop ange-ftp-xfer-size)
	   (ange-ftp-message "%s...%dk" ange-ftp-process-msg kbytes)
	 (let ((percent (/ (* 100 kbytes) ange-ftp-xfer-size)))
	   ;; cut out the redisplay of identical %-age messages.
	   (if (not (eq percent ange-ftp-last-percent))
	       (progn
		 (setq ange-ftp-last-percent percent)
		 (ange-ftp-message "%s...%d%%" ange-ftp-process-msg percent)))))))
  str)

;; Call the function specified by CONT.  CONT can be either a function
;; or a list of a function and some args.  The first two parameters
;; passed to the function will be RESULT and LINE.  The remaining args
;; will be taken from CONT if a list was passed.

(defun ange-ftp-call-cont (cont result line)
  (if cont
      (if (and (listp cont)
	       (not (eq (car cont) 'lambda)))
	  (apply (car cont) result line (cdr cont))
	(funcall cont result line))))

;; Build up a complete line of output from the ftp PROCESS and pass it
;; on to ange-ftp-process-handle-line to deal with.

(defun ange-ftp-process-filter (proc str)
  (let ((buffer (process-buffer proc))
	(old-buffer (current-buffer)))

    ;; Eliminate nulls.
    (while (string-match "\000+" str)
      (setq str (replace-match "" nil nil str))) 

    ;; see if the buffer is still around... it could have been deleted.
    (if (buffer-name buffer)
	(unwind-protect
	    (progn
	      (set-buffer (process-buffer proc))
	      
	      ;; handle hash mark printing
	      (and ange-ftp-process-busy
		   (string-match "^#+$" str)
		   (setq str (ange-ftp-process-handle-hash str)))
	      (comint-output-filter proc str)
	      ;; Replace STR by the result of the comint processing.
	      (setq str (buffer-substring comint-last-output-start
					  (process-mark proc)))
	      (if ange-ftp-process-busy
		  (progn
		    (setq ange-ftp-process-string (concat ange-ftp-process-string
							  str))
		    
		    ;; if we gave an empty password to the USER command earlier
		    ;; then we should send a null password now.
		    (if (string-match "Password: *$" ange-ftp-process-string)
			(send-string proc "\n"))))
	      (while (and ange-ftp-process-busy
			  (string-match "\n" ange-ftp-process-string))
		(let ((line (substring ange-ftp-process-string
				       0
				       (match-beginning 0))))
		  (setq ange-ftp-process-string (substring ange-ftp-process-string
							   (match-end 0)))
		  (while (string-match "^ftp> *" line)
		    (setq line (substring line (match-end 0))))
		  (ange-ftp-process-handle-line line proc)))

	      ;; has the ftp client finished?  if so then do some clean-up
	      ;; actions.
	      (if (not ange-ftp-process-busy)
		  (progn
		    ;; reset the xfer size
		    (setq ange-ftp-xfer-size 0)

		    ;; issue the "done" message since we've finished.
		    (if (and ange-ftp-process-msg
			     ange-ftp-process-verbose
			     ange-ftp-process-result)
			(progn
			  (ange-ftp-message "%s...done" ange-ftp-process-msg)
			  (ange-ftp-repaint-minibuffer)
			  (setq ange-ftp-process-msg nil)))
		    
		    ;; is there a continuation we should be calling?  if so,
		    ;; we'd better call it, making sure we only call it once.
		    (if ange-ftp-process-continue
			(let ((cont ange-ftp-process-continue))
			  (setq ange-ftp-process-continue nil)
			  (ange-ftp-call-cont cont
					      ange-ftp-process-result
					      ange-ftp-process-result-line))))))
	  (set-buffer old-buffer)))))

(defun ange-ftp-process-sentinel (proc str)
  "When ftp process changes state, nuke all file-entries in cache."
  (let ((name (process-name proc)))
    (if (string-match "\\*ftp \\([^@]+\\)@\\([^*]+\\)\\*" name)
	(let ((user (substring name (match-beginning 1) (match-end 1)))
	      (host (substring name (match-beginning 2) (match-end 2))))
	  (ange-ftp-wipe-file-entries host user))))
  (setq ange-ftp-ls-cache-file nil))

;;;; ------------------------------------------------------------
;;;; Gateway support.
;;;; ------------------------------------------------------------

(defun ange-ftp-use-gateway-p (host)
  "Returns whether to access this host via a normal (non-smart) gateway."
  ;; yes, I know that I could simplify the following expression, but it is
  ;; clearer (to me at least) this way.
  (and (not ange-ftp-smart-gateway)
       (save-match-data
	 (not (string-match ange-ftp-local-host-regexp host)))))

(defun ange-ftp-use-smart-gateway-p (host)
  "Returns whether to access this host via a smart gateway."
  (and ange-ftp-smart-gateway
       (save-match-data
	 (not (string-match ange-ftp-local-host-regexp host)))))


;;; ------------------------------------------------------------
;;; Temporary file location and deletion...
;;; ------------------------------------------------------------

(defvar ange-ftp-tmp-name-files ())
(defvar ange-ftp-tmp-name-hashtable (ange-ftp-make-hashtable 10))
(defvar ange-ftp-pid nil)

(defun ange-ftp-get-pid ()
  "Half-hearted attempt to get the current process's id."
  (setq ange-ftp-pid (substring (make-temp-name "") 1)))

(defun ange-ftp-make-tmp-name (host)
  "This routine will return the name of a new file."
  (let* ((template (if (ange-ftp-use-gateway-p host)
		       ange-ftp-gateway-tmp-name-template
		     ange-ftp-tmp-name-template))
	 (pid (or ange-ftp-pid (ange-ftp-get-pid)))
	 (start ?a)
	 file entry)
    (while 
	(progn
	  (setq file (format "%s%c%s" template start pid))
	  (setq entry (intern file ange-ftp-tmp-name-hashtable))
	  (or (memq entry ange-ftp-tmp-name-files)
	      (ange-ftp-real-file-exists-p file)))
      (if (> (setq start (1+ start)) ?z)
	  (progn
	    (setq template (concat template "X"))
	    (setq start ?a))))
    (setq ange-ftp-tmp-name-files
	  (cons entry ange-ftp-tmp-name-files))
    file))

(defun ange-ftp-del-tmp-name (temp)
  (setq ange-ftp-tmp-name-files
	(delq (intern temp ange-ftp-tmp-name-hashtable)
	      ange-ftp-tmp-name-files))
  (condition-case ()
      (ange-ftp-real-delete-file temp)
    (error nil)))

;;;; ------------------------------------------------------------
;;;; Interactive gateway program support.
;;;; ------------------------------------------------------------

(defvar ange-ftp-gwp-running t)
(defvar ange-ftp-gwp-status nil)

(defun ange-ftp-gwp-sentinel (proc str)
  (setq ange-ftp-gwp-running nil))

(defun ange-ftp-gwp-filter (proc str)
  (comint-output-filter proc str)
  (save-excursion
    (set-buffer (process-buffer proc))
    ;; Replace STR by the result of the comint processing.
    (setq str (buffer-substring comint-last-output-start (process-mark proc))))
  (cond ((string-match "login: *$" str)
	 (send-string proc
		      (concat
		       (let ((ange-ftp-default-user t))
			 (ange-ftp-get-user ange-ftp-gateway-host))
		       "\n")))
	((string-match "Password: *$" str)
	 (send-string proc
		      (concat
		       (ange-ftp-get-passwd ange-ftp-gateway-host
					    (ange-ftp-get-user
					     ange-ftp-gateway-host))
		       "\n")))
	((string-match ange-ftp-gateway-fatal-msgs str)
	 (delete-process proc)
	 (setq ange-ftp-gwp-running nil))
	((string-match ange-ftp-gateway-prompt-pattern str)
	 (setq ange-ftp-gwp-running nil
	       ange-ftp-gwp-status t))))

(defun ange-ftp-gwp-start (host user name args)
  "Login to the gateway machine and fire up an ftp process."
  (let* ((gw-user (ange-ftp-get-user ange-ftp-gateway-host))
	 ;; It would be nice to make process-connection-type nil,
	 ;; but that doesn't work: ftp never responds.
	 ;; Can anyone find a fix for that?
	 (proc (let ((process-connection-type t))
		 (start-process name name
				ange-ftp-gateway-program
				ange-ftp-gateway-host)))
	 (ftp (mapconcat (function identity) args " ")))
    (process-kill-without-query proc)
    (set-process-sentinel proc (function ange-ftp-gwp-sentinel))
    (set-process-filter proc (function ange-ftp-gwp-filter))
    (save-excursion
      (set-buffer (process-buffer proc))
      (goto-char (point-max))
      (set-marker (process-mark proc) (point)))
    (setq ange-ftp-gwp-running t
	  ange-ftp-gwp-status nil)
    (ange-ftp-message "Connecting to gateway %s..." ange-ftp-gateway-host)
    (while ange-ftp-gwp-running		;perform login sequence
      (accept-process-output proc))
    (if (not ange-ftp-gwp-status)
	(ange-ftp-error host user "unable to login to gateway"))
    (ange-ftp-message "Connecting to gateway %s...done" ange-ftp-gateway-host)
    (setq ange-ftp-gwp-running t
	  ange-ftp-gwp-status nil)
    (process-send-string proc ange-ftp-gateway-setup-term-command)
    (while ange-ftp-gwp-running		;zap ^M's and double echoing.
      (accept-process-output proc))
    (if (not ange-ftp-gwp-status)
	(ange-ftp-error host user "unable to set terminal modes on gateway"))
    (setq ange-ftp-gwp-running t
	  ange-ftp-gwp-status nil)
    (process-send-string proc (concat "exec " ftp "\n")) ;spawn ftp process
    proc))

;;;; ------------------------------------------------------------
;;;; Support for sending commands to the ftp process.
;;;; ------------------------------------------------------------

(defun ange-ftp-raw-send-cmd (proc cmd &optional msg cont nowait)
  "Low-level routine to send the given ftp CMD to the ftp PROCESS.
MSG is an optional message to output before and after the command.
If CONT is non-nil then it is either a function or a list of function and
some arguments.  The function will be called when the ftp command has completed.
If CONT is nil then this routine will return \( RESULT . LINE \) where RESULT
is whether the command was successful, and LINE is the line from the FTP
process that caused the command to complete.
If NOWAIT is given then the routine will return immediately the command has
been queued with no result.  CONT will still be called, however."
  (if (memq (process-status proc) '(run open))
      (save-excursion
	(set-buffer (process-buffer proc))
	(ange-ftp-wait-not-busy proc)
	(setq ange-ftp-process-string ""
	      ange-ftp-process-result-line ""
	      ange-ftp-process-busy t
	      ange-ftp-process-result nil
	      ange-ftp-process-multi-skip nil
	      ange-ftp-process-msg msg
	      ange-ftp-process-continue cont
	      ange-ftp-hash-mark-count 0
	      ange-ftp-last-percent -1
	      cmd (concat cmd "\n"))
	(and msg ange-ftp-process-verbose (ange-ftp-message "%s..." msg))
	(goto-char (point-max))
	(move-marker comint-last-input-start (point))
	;; don't insert the password into the buffer on the USER command.
	(save-match-data
	  (if (string-match "^user \"[^\"]*\"" cmd)
	      (insert (substring cmd 0 (match-end 0)) " Turtle Power!\n")
	    (insert cmd)))
	(move-marker comint-last-input-end (point))
	(send-string proc cmd)
	(set-marker (process-mark proc) (point))
	(if nowait
	    nil
	  (ange-ftp-wait-not-busy proc)
	  (if cont
	      nil			;cont has already been called
	    (cons ange-ftp-process-result ange-ftp-process-result-line))))))

;; Wait for the ange-ftp process PROC not to be busy.
(defun ange-ftp-wait-not-busy (proc)
  (save-excursion
    (set-buffer (process-buffer proc))
    (condition-case nil
	;; This is a kludge to let user quit in case ftp gets hung.
	;; It matters because this function can be called from the filter.
	;; It is bad to allow quitting in a filter, but getting hung
	;; is worse.  By binding quit-flag to nil, we might avoid
	;; most of the probability of getting screwed because the user
	;; wants to quit some command.
	(let ((quit-flag nil)
	      (inhibit-quit nil))
	  (while ange-ftp-process-busy
	    (accept-process-output proc)))
      (quit
       ;; If the user does quit out of this,
       ;; kill the process.  That stops any transfer in progress.
       ;; The next operation will open a new ftp connection.
       (delete-process proc)
       (signal 'quit nil)))))

(defun ange-ftp-nslookup-host (host)
  "Attempt to resolve the given HOSTNAME using nslookup if possible."
  (interactive "sHost:  ")
  (if ange-ftp-nslookup-program
      (let ((default-directory
	      (if (file-accessible-directory-p default-directory)
		  default-directory
		exec-directory))
	    ;; It would be nice to make process-connection-type nil,
	    ;; but that doesn't work: ftp never responds.
	    ;; Can anyone find a fix for that?
	    (proc (let ((process-connection-type t))
		    (start-process " *nslookup*" " *nslookup*"
				   ange-ftp-nslookup-program host)))
	    (res host))
	(process-kill-without-query proc)
	(save-excursion
	  (set-buffer (process-buffer proc))
	  (while (memq (process-status proc) '(run open))
	    (accept-process-output proc))
	  (goto-char (point-min))
	  (if (re-search-forward "Name:.*\nAddress: *\\(.*\\)$" nil t)
	      (setq res (buffer-substring (match-beginning 1)
					  (match-end 1))))
	  (kill-buffer (current-buffer)))
	res)
    host))

(defun ange-ftp-start-process (host user name)
  "Spawn a new ftp process ready to connect to machine HOST and give it NAME.
If HOST is only ftp-able through a gateway machine then spawn a shell
on the gateway machine to do the ftp instead."
  (let* ((use-gateway (ange-ftp-use-gateway-p host))
	 (use-smart-ftp (and (not ange-ftp-gateway-host)
			     (ange-ftp-use-smart-gateway-p host)))
	 (ftp-prog (if (or use-gateway
			   use-smart-ftp) 
		       ange-ftp-gateway-ftp-program-name
		     ange-ftp-ftp-program-name))
	 (args (append (list ftp-prog) ange-ftp-ftp-program-args))
	 ;; Without the following binding, ange-ftp-start-process
	 ;; recurses on file-accessible-directory-p, since it needs to
	 ;; restart its process in order to determine anything about
	 ;; default-directory.
	 (file-name-handler-alist)
	 (default-directory
	   (if (file-accessible-directory-p default-directory)
	       default-directory
	     exec-directory))
	 proc)
    ;; It would be nice to make process-connection-type nil,
    ;; but that doesn't work: ftp never responds.
    ;; Can anyone find a fix for that?
    (let ((process-connection-type t)
	  (process-environment process-environment)
	  (buffer (get-buffer-create name)))
      (save-excursion
	(set-buffer buffer)
	(internal-ange-ftp-mode))
      ;; This tells GNU ftp not to output any fancy escape sequences.
      (setenv "TERM" "dumb")
      (if use-gateway
	  (if ange-ftp-gateway-program-interactive
	      (setq proc (ange-ftp-gwp-start host user name args))
	    (setq proc (apply 'start-process name name
			      (append (list ange-ftp-gateway-program
					    ange-ftp-gateway-host)
				      args))))
	(setq proc (apply 'start-process name name args))))
    (save-excursion
      (set-buffer (process-buffer proc))
      (goto-char (point-max))
      (set-marker (process-mark proc) (point)))
    (process-kill-without-query proc)
    (set-process-sentinel proc (function ange-ftp-process-sentinel))
    (set-process-filter proc (function ange-ftp-process-filter))
    ;; On Windows, the standard ftp client buffers its output (because
    ;; stdout is a pipe handle) so the startup message may never appear:
    ;; `accept-process-output' at this point would hang indefinitely.
    ;; However, sending an innocuous command ("help foo") forces some
    ;; output that will be ignored, which is just as good.  Once we
    ;; start sending normal commands, the output no longer appears to be
    ;; buffered, and everything works correctly.  My guess is that the
    ;; output of interest is being sent to stderr which is not buffered.
    (when (eq system-type 'windows-nt)
      ;; force ftp output to be treated as DOS text, otherwise the
      ;; output of "help foo" confuses the EOL detection logic.
      (set-process-coding-system proc 'raw-text-dos)
      (process-send-string proc "help foo\n"))
    (accept-process-output proc)	;wait for ftp startup message
    proc))

(put 'internal-ange-ftp-mode 'mode-class 'special)

(defun internal-ange-ftp-mode ()
  "Major mode for interacting with the FTP process.

\\{comint-mode-map}"
  (interactive)
  (comint-mode)
  (setq major-mode 'internal-ange-ftp-mode)
  (setq mode-name "Internal Ange-ftp")
  (let ((proc (get-buffer-process (current-buffer))))
    (make-local-variable 'ange-ftp-process-string)
    (setq ange-ftp-process-string "")
    (make-local-variable 'ange-ftp-process-busy)
    (make-local-variable 'ange-ftp-process-result)
    (make-local-variable 'ange-ftp-process-msg)
    (make-local-variable 'ange-ftp-process-multi-skip)
    (make-local-variable 'ange-ftp-process-result-line)
    (make-local-variable 'ange-ftp-process-continue)
    (make-local-variable 'ange-ftp-hash-mark-count)
    (make-local-variable 'ange-ftp-binary-hash-mark-size)
    (make-local-variable 'ange-ftp-ascii-hash-mark-size)
    (make-local-variable 'ange-ftp-hash-mark-unit)
    (make-local-variable 'ange-ftp-xfer-size)
    (make-local-variable 'ange-ftp-last-percent)
    (setq ange-ftp-hash-mark-count 0)
    (setq ange-ftp-xfer-size 0)
    (setq ange-ftp-process-result-line "")

    (setq comint-prompt-regexp "^ftp> ")
    (make-local-variable 'comint-password-prompt-regexp)
    ;; This is a regexp that can't match anything.
    ;; ange-ftp has its own ways of handling passwords.
    (setq comint-password-prompt-regexp "^a\\'z")
    (make-local-variable 'paragraph-start)
    (setq paragraph-start comint-prompt-regexp)))

(defun ange-ftp-smart-login (host user pass account proc)
  "Connect to the FTP-server on HOST as USER using PASSWORD and ACCOUNT.
PROC is the FTP-client's process.  This routine uses the smart-gateway
host specified in ``ange-ftp-gateway-host''."
  (let ((result (ange-ftp-raw-send-cmd
		 proc
		 (format "open %s %s"
			 (ange-ftp-nslookup-host ange-ftp-gateway-host)
			 ange-ftp-smart-gateway-port)
		 (format "Opening FTP connection to %s via %s"
			 host
			 ange-ftp-gateway-host))))
    (or (car result)
	(ange-ftp-error host user 
			(concat "OPEN request failed: "
				(cdr result))))
    (setq result (ange-ftp-raw-send-cmd
		  proc (format "user \"%s\"@%s %s %s"
			       user
			       (ange-ftp-nslookup-host host)
			       pass
			       account)
		  (format "Logging in as user %s@%s"
			  user host)))
    (or (car result)
	(progn
	  (ange-ftp-set-passwd host user nil) ; reset password
	  (ange-ftp-set-account host user nil) ; reset account
	  (ange-ftp-error host user
			  (concat "USER request failed: "
				  (cdr result)))))))

(defun ange-ftp-normal-login (host user pass account proc)
  "Connect to the FTP-server on HOST as USER using PASSWORD and ACCOUNT.
PROC is the process to the FTP-client."
  (let* ((nshost (ange-ftp-nslookup-host host))
	 (result (ange-ftp-raw-send-cmd
		 proc
		 (format "open %s" nshost)
		 (format "Opening FTP connection to %s" host))))
    (or (car result)
	(ange-ftp-error host user
			(concat "OPEN request failed: "
				(cdr result))))
    (setq result (ange-ftp-raw-send-cmd
		  proc
		  (if (and (ange-ftp-use-smart-gateway-p host)
			   ange-ftp-gateway-host)
		      (format "user \"%s\"@%s %s %s" user nshost pass account)
		    (format "user \"%s\" %s %s" user pass account))
		  (format "Logging in as user %s@%s" user host)))
    (or (car result)
	(progn
	  (ange-ftp-set-passwd host user nil) ;reset password.
	  (ange-ftp-set-account host user nil) ;reset account.
	  (ange-ftp-error host user
			  (concat "USER request failed: "
				  (cdr result)))))))

;; ange@hplb.hpl.hp.com says this should not be changed.
(defvar ange-ftp-hash-mark-msgs
  "[hH]ash mark [^0-9]*\\([0-9]+\\)"
  "*Regexp matching the FTP client's output upon doing a HASH command.")

(defun ange-ftp-guess-hash-mark-size (proc)
  (if ange-ftp-send-hash
      (save-excursion
	(set-buffer (process-buffer proc))
	(let* ((status (ange-ftp-raw-send-cmd proc "hash"))
	       (result (car status))
	       (line (cdr status)))
	  (save-match-data
	    (if (string-match ange-ftp-hash-mark-msgs line)
		(let ((size (string-to-int
			    (substring line
				       (match-beginning 1)
				       (match-end 1)))))
		  (setq ange-ftp-ascii-hash-mark-size size
			ange-ftp-hash-mark-unit (ash size -4))

		  ;; if a default value for this is set, use that value.
		  (or ange-ftp-binary-hash-mark-size
		      (setq ange-ftp-binary-hash-mark-size size)))))))))

(defun ange-ftp-get-process (host user)
  "Return an FTP subprocess connected to HOST and logged in as USER.
Create a new process if needed."
  (let* ((name (ange-ftp-ftp-process-buffer host user))
	 (proc (get-process name)))
    (if (and proc (memq (process-status proc) '(run open)))
	proc
      ;; Must delete dead process so that new process can reuse the name.
      (if proc (delete-process proc))
      (let ((pass (ange-ftp-quote-string
		   (ange-ftp-get-passwd host user)))
	    (account (ange-ftp-quote-string
		      (ange-ftp-get-account host user))))
	;; grab a suitable process.
	(setq proc (ange-ftp-start-process host user name))
	
	;; login to FTP server.
	(if (and (ange-ftp-use-smart-gateway-p host)
		 ange-ftp-gateway-host)
	    (ange-ftp-smart-login host user pass account proc)
	  (ange-ftp-normal-login host user pass account proc))
      
	;; Tell client to send back hash-marks as progress.  It isn't usually
	;; fatal if this command fails.
	(ange-ftp-guess-hash-mark-size proc)

	;; Guess at the host type.
	(ange-ftp-guess-host-type host user)

	;; Run any user-specified hooks.  Note that proc, host and user are
	;; dynamically bound at this point.
	(run-hooks 'ange-ftp-process-startup-hook))
      proc)))

;; Variables for caching host and host-type
(defvar ange-ftp-host-cache nil)
(defvar ange-ftp-host-type-cache nil)

;; If ange-ftp-host-type is called with the optional user
;; argument, it will attempt to guess the host type by connecting
;; as user, if necessary. For efficiency, I have tried to give this
;; optional second argument only when necessary. Have I missed any calls
;; to ange-ftp-host-type where it should have been supplied?

(defun ange-ftp-host-type (host &optional user)
  "Return a symbol which represents the type of the HOST given.
If the optional argument USER is given, attempts to guess the
host-type by logging in as USER."
  (cond ((null host) 'unix)
	;; Return `unix' if HOST is nil, since that's the most vanilla
	;; possible return value.
	((eq host ange-ftp-host-cache)
	 ange-ftp-host-type-cache)
	;; Trigger an ftp connection, in case we need to guess at the host type.
	((and user (ange-ftp-get-process host user) (eq host ange-ftp-host-cache))
	 ange-ftp-host-type-cache)
	(t
         (setq ange-ftp-host-cache host
	       ange-ftp-host-type-cache
	       (cond ((ange-ftp-dumb-unix-host host)
		      'dumb-unix)
		     ;;		  ((and (fboundp 'ange-ftp-vos-host)
		     ;;			(ange-ftp-vos-host host))
		     ;;		   'vos)
		     ((and (fboundp 'ange-ftp-vms-host)
			   (ange-ftp-vms-host host))
		      'vms)
		     ((and (fboundp 'ange-ftp-mts-host)
			   (ange-ftp-mts-host host))
		      'mts)
		     ((and (fboundp 'ange-ftp-cms-host)
			   (ange-ftp-cms-host host))
		      'cms)
		     (t
		      'unix))))))

;; It would be nice to abstract the functions ange-ftp-TYPE-host and
;; ange-ftp-add-TYPE-host. The trick is to abstract these functions
;; without sacrificing speed. Also, having separate variables
;; ange-ftp-TYPE-regexp is more user friendly then requiring the user to
;; set an alist to indicate that a host is of a given type. Even with
;; automatic host type recognition, setting a regexp is still a good idea
;; (for efficiency) if you log into a particular non-UNIX host frequently.

(defvar ange-ftp-fix-name-func-alist nil
  "Alist saying how to convert file name to the host's syntax.
Association list of \( TYPE \. FUNC \) pairs, where FUNC is a routine
which can change a UNIX file name into a name more suitable for a host of type
TYPE.")

(defvar ange-ftp-fix-dir-name-func-alist nil
  "Alist saying how to convert directory name to the host's syntax.
Association list of \( TYPE \. FUNC \) pairs, where FUNC is a routine
which can change UNIX directory name into a directory name more suitable
for a host of type TYPE.")

;; *** Perhaps the sense of this variable should be inverted, since there
;; *** is only 1 host type that can take ls-style listing options.
(defvar ange-ftp-dumb-host-types '(dumb-unix)
  "List of host types that can't take UNIX ls-style listing options.")

(defun ange-ftp-send-cmd (host user cmd &optional msg cont nowait)
  "Find an ftp process connected to HOST logged in as USER and send it CMD.
MSG is an optional status message to be output before and after issuing the
command.
See the documentation for ange-ftp-raw-send-cmd for a description of CONT
and NOWAIT."
  ;; Handle conversion to remote file name syntax and remote ls option
  ;; capability.
  (let ((cmd0 (car cmd))
	(cmd1 (nth 1 cmd))
	(ange-ftp-this-user user)
	(ange-ftp-this-host host)
	(ange-ftp-this-msg msg)
	cmd2 cmd3 host-type fix-name-func)

    (cond
     
     ;; pwd case (We don't care what host-type.)
     ((null cmd1))
     
     ;; cmd == 'dir "remote-name" "local-name" "ls-switches"
     ((progn
       (setq cmd2 (nth 2 cmd)
	     host-type (ange-ftp-host-type host user))
       ;; This will trigger an FTP login, if one doesn't exist
       (eq cmd0 'dir))
      (setq cmd1 (funcall
		  (or (cdr (assq host-type ange-ftp-fix-dir-name-func-alist))
		      'identity)
		  cmd1)
	    cmd3 (nth 3 cmd))
      ;; Need to deal with the HP-UX ftp bug. This should also allow
      ;; us to resolve symlinks to directories on SysV machines. (Sebastian will
      ;; be happy.)
      (and (eq host-type 'unix)
	   (string-match "/$" cmd1)
	   (not (string-match "R" cmd3))
	   (setq cmd1 (concat cmd1 ".")))

      ;; If the dir name contains a space, some ftp servers will
      ;; refuse to list it.  We instead change directory to the
      ;; directory in question and ls ".".
      (when (string-match " " cmd1)
	(ange-ftp-cd host user (nth 1 cmd))
	(setq cmd1 "."))

      ;; If the remote ls can take switches, put them in
      (or (memq host-type ange-ftp-dumb-host-types)
	  (setq cmd0 'ls
		cmd1 (format "\"%s %s\"" cmd3 cmd1))))
     
     ;; First argument is the remote name
     ((progn
	(setq fix-name-func (or (cdr (assq host-type
					   ange-ftp-fix-name-func-alist))
				'identity))
	(memq cmd0 '(get delete mkdir rmdir cd)))
      (setq cmd1 (funcall fix-name-func cmd1)))

     ;; Second argument is the remote name
     ((memq cmd0 '(append put chmod))
      (setq cmd2 (funcall fix-name-func cmd2)))

     ;; Both arguments are remote names
     ((eq cmd0 'rename)
      (setq cmd1 (funcall fix-name-func cmd1)
	    cmd2 (funcall fix-name-func cmd2))))
	  
    ;; Turn the command into one long string 
    (setq cmd0 (symbol-name cmd0))
    (setq cmd (concat cmd0
		      (and cmd1 (concat " " cmd1))
		      (and cmd2 (concat " " cmd2))))

    ;; Actually send the resulting command.
    (let (afsc-result
	  afsc-line)
      (ange-ftp-raw-send-cmd
       (ange-ftp-get-process host user)
       cmd
       msg
       (list
	(function (lambda (result line host user
				  cmd msg cont nowait)
		    (or cont
			(setq afsc-result result
			      afsc-line line))
		    (if result
			(ange-ftp-call-cont cont result line)
		      (ange-ftp-raw-send-cmd
		       (ange-ftp-get-process host user)
		       cmd
		       msg
		       (list
			(function (lambda (result line cont)
				    (or cont
					(setq afsc-result result
					      afsc-line line))
				    (ange-ftp-call-cont cont result line)))
			cont)
		       nowait))))
	host user cmd msg cont nowait)
       nowait)

      (if nowait
	  nil
	(if cont
	    nil
	  (cons afsc-result afsc-line))))))

;; It might be nice to message users about the host type identified,
;; but there is so much other messaging going on, it would not be
;; seen. No point in slowing things down just so users can read
;; a host type message.

(defconst ange-ftp-cms-name-template
  (concat
   "^[-A-Z0-9$*][-A-Z0-9$*]?[-A-Z0-9$*]?[-A-Z0-9$*]?[-A-Z0-9$*]?"
   "[-A-Z0-9$*]?[-A-Z0-9$*]?[-A-Z0-9$*]?\\.[0-9][0-9][0-9A-Z]$"))
(defconst ange-ftp-vms-name-template
  "^[-A-Z0-9_$]+:\\[[-A-Z0-9_$]+\\(\\.[-A-Z0-9_$]+\\)*\\]$")
(defconst ange-ftp-mts-name-template
  "^[A-Z0-9._][A-Z0-9._][A-Z0-9._][A-Z0-9._]:$")

(defun ange-ftp-guess-host-type (host user)
  "Guess at the the host type of HOST.
Works by doing a pwd and examining the directory syntax."
  (let ((host-type (ange-ftp-host-type host))
	(key (concat host "/" user "/~")))
    (if (eq host-type 'unix)
	;; Note that ange-ftp-host-type returns unix as the default value.
	(save-match-data
	  (let* ((result (ange-ftp-get-pwd host user))
		 (dir (car result))
		 fix-name-func)
	    (cond ((null dir)
		   (message "Warning! Unable to get home directory")
		   (sit-for 1)
		   (if (string-match
			"^450 No current working directory defined$"
			(cdr result))
		       
		       ;; We'll assume that if pwd bombs with this
		       ;; error message, then it's CMS.
		       (progn
			 (ange-ftp-add-cms-host host)
			 (setq ange-ftp-host-cache host
			       ange-ftp-host-type-cache 'cms))))

		  ;; try for VMS
		  ((string-match ange-ftp-vms-name-template dir)
		   (ange-ftp-add-vms-host host)
		   ;; The add-host functions clear the host type cache.
		   ;; Therefore, need to set the cache afterwards.
		   (setq ange-ftp-host-cache host
			 ange-ftp-host-type-cache 'vms))

		  ;; try for MTS
		  ((string-match ange-ftp-mts-name-template dir)
		   (ange-ftp-add-mts-host host)
		   (setq ange-ftp-host-cache host
			 ange-ftp-host-type-cache 'mts))
		  
		  ;; try for CMS
		  ((string-match ange-ftp-cms-name-template dir)
		   (ange-ftp-add-cms-host host)
		   (setq ange-ftp-host-cache host
			 ange-ftp-host-type-cache 'cms))

		  ;; assume UN*X
		  (t
		   (setq ange-ftp-host-cache host
			 ange-ftp-host-type-cache 'unix)))

	    ;; Now that we have done a pwd, might as well put it in
	    ;; the expand-dir hashtable.
	    (let ((ange-ftp-this-user user)
		  (ange-ftp-this-host host))
	      (setq fix-name-func (cdr (assq ange-ftp-host-type-cache
					     ange-ftp-fix-name-func-alist)))
	      (if fix-name-func
		  (setq dir (funcall fix-name-func dir 'reverse))))
	    (ange-ftp-put-hash-entry key dir
				     ange-ftp-expand-dir-hashtable))))

    ;; In the special case of CMS make sure that know the
    ;; expansion of the home minidisk now, because we will
    ;; be doing a lot of cd's.
    (if (and (eq host-type 'cms)
	     (not (ange-ftp-hash-entry-exists-p
		   key ange-ftp-expand-dir-hashtable)))
	(let ((dir (car (ange-ftp-get-pwd host user))))
	  (if dir
	      (ange-ftp-put-hash-entry key (concat "/" dir)
				       ange-ftp-expand-dir-hashtable)
	    (message "Warning! Unable to get home directory")
	    (sit-for 1))))))


;;;; ------------------------------------------------------------
;;;; Remote file and directory listing support.
;;;; ------------------------------------------------------------

;; Returns whether HOST's FTP server doesn't like \'ls\' or \'dir\' commands
;; to take switch arguments.
(defun ange-ftp-dumb-unix-host (host)
  (and host ange-ftp-dumb-unix-host-regexp
       (save-match-data
	 (string-match ange-ftp-dumb-unix-host-regexp host))))

(defun ange-ftp-add-dumb-unix-host (host)
  "Interactively adds a given HOST to ange-ftp-dumb-unix-host-regexp."
  (interactive
   (list (read-string "Host: "
		      (let ((name (or (buffer-file-name) default-directory)))
			(and name (car (ange-ftp-ftp-name name)))))))
  (if (not (ange-ftp-dumb-unix-host host))
      (setq ange-ftp-dumb-unix-host-regexp
	    (concat "^" (regexp-quote host) "$"
		    (and ange-ftp-dumb-unix-host-regexp "\\|")
		    ange-ftp-dumb-unix-host-regexp)
	    ange-ftp-host-cache nil)))

(defvar ange-ftp-parse-list-func-alist nil
  "Alist saying how to parse directory listings for certain OS types.
Association list of \( TYPE \. FUNC \) pairs.  The FUNC is a routine
which can parse the output from a DIR listing for a host of type TYPE.")

;; With no-error nil, this function returns:
;; an error if file is not an ange-ftp-name
;;                      (This should never happen.) 
;; an error if either the listing is unreadable or there is an ftp error.
;; the listing (a string), if everything works.
;; 
;; With no-error t, it returns:
;; an error if not an ange-ftp-name
;; error if listing is unreadable (most likely caused by a slow connection)
;; nil if ftp error (this is because although asking to list a nonexistent
;;                   directory on a remote unix machine usually (except
;;                   maybe for dumb hosts) returns an ls error, but no
;;                   ftp error, if the same is done on a VMS machine,
;;                   an ftp error is returned. Need to trap the error
;;                   so we can go on and try to list the parent.)
;; the listing, if everything works.

;; If WILDCARD is non-nil, then this implements the guts of insert-directory
;; in the wildcard case.  Then we make a relative directory listing
;; of FILE within the directory specified by `default-directory'.

(defvar ange-ftp-before-parse-ls-hook nil
  "Normal hook run before parsing the text of an ftp directory listing.")

(defun ange-ftp-ls (file lsargs parse &optional no-error wildcard)
  "Return the output of an `DIR' or `ls' command done over ftp.
FILE is the full name of the remote file, LSARGS is any args to pass to the
`ls' command, and PARSE specifies that the output should be parsed and stored
away in the internal cache."
  ;; If parse is t, we assume that file is a directory. i.e. we only parse
  ;; full directory listings.
  (let* ((ange-ftp-this-file (ange-ftp-expand-file-name file))
	 (parsed (ange-ftp-ftp-name ange-ftp-this-file)))
    (if parsed
	(let* ((host (nth 0 parsed))
	       (user (nth 1 parsed))
	       (name (ange-ftp-quote-string (nth 2 parsed)))
	       (key (directory-file-name ange-ftp-this-file))
	       (host-type (ange-ftp-host-type host user))
	       (dumb (memq host-type ange-ftp-dumb-host-types))
	       result
	       temp
	       lscmd parse-func)
	  (if (string-equal name "")
	      (setq name
		    (ange-ftp-real-file-name-as-directory
		          (ange-ftp-expand-dir host user "~"))))
	  (if (and ange-ftp-ls-cache-file
		   (string-equal key ange-ftp-ls-cache-file)
		   ;; Don't care about lsargs for dumb hosts.
		   (or dumb (string-equal lsargs ange-ftp-ls-cache-lsargs)))
	      ange-ftp-ls-cache-res
	    (setq temp (ange-ftp-make-tmp-name host))
	    (if wildcard
		(progn
		  (ange-ftp-cd host user (file-name-directory name))
		  (setq lscmd (list 'dir file temp lsargs)))
	      (setq lscmd (list 'dir name temp lsargs)))
	    (unwind-protect
		(if (car (setq result (ange-ftp-send-cmd
				       host
				       user
				       lscmd
				       (format "Listing %s"
					       (ange-ftp-abbreviate-filename
						ange-ftp-this-file)))))
		    (save-excursion
		      (set-buffer (get-buffer-create
				   ange-ftp-data-buffer-name))
		      (erase-buffer)
		      (if (ange-ftp-real-file-readable-p temp)
			  (ange-ftp-real-insert-file-contents temp)
			(sleep-for ange-ftp-retry-time)
					;wait for file to possibly appear
			(if (ange-ftp-real-file-readable-p temp)
			    ;; Try again.
			    (ange-ftp-real-insert-file-contents temp)
			  (ange-ftp-error host user
					  (format
					   "list data file %s not readable"
					   temp))))
		      (run-hooks 'ange-ftp-before-parse-ls-hook)
		      (if parse
			  (ange-ftp-set-files
			   ange-ftp-this-file
			   (if (setq
				parse-func
				(cdr (assq host-type
					   ange-ftp-parse-list-func-alist)))
			       (funcall parse-func)
			     (ange-ftp-parse-dired-listing lsargs))))
		      (setq ange-ftp-ls-cache-file key
			    ange-ftp-ls-cache-lsargs lsargs
					; For dumb hosts-types this is
					; meaningless but harmless.
			    ange-ftp-ls-cache-res (buffer-string))
		      ;; (kill-buffer (current-buffer))
		      ange-ftp-ls-cache-res)
		  (if no-error
		      nil
		    (ange-ftp-error host user
				    (concat "DIR failed: " (cdr result)))))
	      (ange-ftp-del-tmp-name temp))))
      (error "Should never happen. Please report. Bug ref. no.: 1"))))

;;;; ------------------------------------------------------------
;;;; Directory information caching support.
;;;; ------------------------------------------------------------

(defconst ange-ftp-date-regexp
  (let* ((l "\\([A-Za-z]\\|[^\0-\177]\\)")
	 ;; In some locales, month abbreviations are as short as 2 letters,
	 ;; and they can be padded on the right with spaces.
	 (month (concat l l "+ *"))
	 ;; Recognize any non-ASCII character.  
	 ;; The purpose is to match a Kanji character.
	 (k "[^\0-\177]")
	 (s " ")
	 (mm "[ 0-1][0-9]")
	 (dd "[ 0-3][0-9]")
	 (western (concat "\\(" month s dd "\\|" dd s month "\\)"))
	 (japanese (concat mm k s dd k)))
	 ;; Require the previous column to end in a digit.
	 ;; This avoids recognizing `1 may 1997' as a date in the line:
	 ;; -r--r--r--   1 may      1997        1168 Oct 19 16:49 README
    (concat "[0-9]" s "\\(" western "\\|" japanese "\\)" s))
  "Regular expression to match up to the column before the file name in a
directory listing.  This regular expression is designed to recognize dates
regardless of the language.")

(defvar ange-ftp-add-file-entry-alist nil
  "Alist saying how to add file entries on certain OS types.
Association list of pairs \( TYPE \. FUNC \), where FUNC
is a function to be used to add a file entry for the OS TYPE. The
main reason for this alist is to deal with file versions in VMS.")

(defvar ange-ftp-delete-file-entry-alist nil
  "Alist saying how to delete files on certain OS types.
Association list of pairs \( TYPE \. FUNC \), where FUNC
is a function to be used to delete a file entry for the OS TYPE.
The main reason for this alist is to deal with file versions in VMS.")

(defun ange-ftp-add-file-entry (name &optional dir-p)
  "Add a file entry for file NAME, if its directory info exists."
  (funcall (or (cdr (assq (ange-ftp-host-type
			   (car (ange-ftp-ftp-name name)))
			  ange-ftp-add-file-entry-alist))
	       'ange-ftp-internal-add-file-entry)
	   name dir-p)
  (setq ange-ftp-ls-cache-file nil))

(defun ange-ftp-delete-file-entry (name &optional dir-p)
  "Delete the file entry for file NAME, if its directory info exists."
  (funcall (or (cdr (assq (ange-ftp-host-type
			   (car (ange-ftp-ftp-name name)))
			  ange-ftp-delete-file-entry-alist))
	       'ange-ftp-internal-delete-file-entry)
	   name dir-p)
  (setq ange-ftp-ls-cache-file nil))

(defmacro ange-ftp-parse-filename ()
  ;;Extract the filename from the current line of a dired-like listing.
  (` (let ((eol (progn (end-of-line) (point))))
       (beginning-of-line)
       (if (re-search-forward ange-ftp-date-regexp eol t)
	   (progn
	     (skip-chars-forward " ")
	     (skip-chars-forward "^ " eol)
	     (skip-chars-forward " " eol)
	     ;; We bomb on filenames starting with a space.
	     (buffer-substring (point) eol))))))
  
;; This deals with the F switch. Should also do something about
;; unquoting names obtained with the SysV b switch and the GNU Q
;; switch. See Sebastian's dired-get-filename.

(defmacro ange-ftp-ls-parser ()
  ;; Note that switches is dynamically bound.
  ;; Meant to be called by ange-ftp-parse-dired-listing
  (` (let ((tbl (ange-ftp-make-hashtable))
	   (used-F (and (stringp switches)
			(string-match "F" switches)))
	   file-type symlink directory file)
       (while (setq file (ange-ftp-parse-filename))
	 (beginning-of-line)
	 (skip-chars-forward "\t 0-9")
	 (setq file-type (following-char)
	       directory (eq file-type ?d))
	 (if (eq file-type ?l)
	     (if (string-match " -> " file)
		 (setq symlink (substring file (match-end 0))
		       file (substring file 0 (match-beginning 0)))
	       ;; Shouldn't happen
	       (setq symlink ""))
	   (setq symlink nil))
	 ;; Only do a costly regexp search if the F switch was used.
	 (if (and used-F
		  (not (string-equal file ""))
		  (looking-at
		   ".[-r][-w]\\([^ ]\\)[-r][-w]\\([^ ]\\)[-r][-w]\\([^ ]\\)"))
	     (let ((socket (eq file-type ?s))
		   (executable
		    (and (not symlink) ; x bits don't mean a thing for symlinks
			 (string-match "[xst]"
				       (concat
					(buffer-substring
					 (match-beginning 1)
					 (match-end 1))
					(buffer-substring
					 (match-beginning 2)
					 (match-end 2))
					(buffer-substring
					 (match-beginning 3)
					 (match-end 3)))))))
	       ;; Some ls's with the F switch mark symlinks with an @ (ULTRIX)
	       ;; and others don't. (sigh...) Beware, that some Unix's don't
	       ;; seem to believe in the F-switch
	       (if (or (and symlink (string-match "@$" file))
		       (and directory (string-match "/$" file))
		       (and executable (string-match "*$" file))
		       (and socket (string-match "=$" file)))
		   (setq file (substring file 0 -1)))))
	 (ange-ftp-put-hash-entry file (or symlink directory) tbl)
	 (forward-line 1))
       (ange-ftp-put-hash-entry "." t tbl)
       (ange-ftp-put-hash-entry ".." t tbl)
       tbl)))

;;; The dl stuff for descriptive listings

(defvar ange-ftp-dl-dir-regexp nil
  "Regexp matching directories which are listed in dl format.
This regexp should not be anchored with a trailing `$', because it should
match subdirectories as well.")

(defun ange-ftp-add-dl-dir (dir)
  "Interactively adds a DIR to ange-ftp-dl-dir-regexp."
  (interactive
   (list (read-string "Directory: "
		      (let ((name (or (buffer-file-name) default-directory)))
			(and name (ange-ftp-ftp-name name)
			     (file-name-directory name))))))
  (if (not (and ange-ftp-dl-dir-regexp
		(string-match ange-ftp-dl-dir-regexp dir)))
      (setq ange-ftp-dl-dir-regexp
	    (concat "^" (regexp-quote dir)
		    (and ange-ftp-dl-dir-regexp "\\|")
		    ange-ftp-dl-dir-regexp))))

(defmacro ange-ftp-dl-parser ()
  ;; Parse the current buffer, which is assumed to be a descriptive
  ;; listing, and return a hashtable.
  (` (let ((tbl (ange-ftp-make-hashtable)))
       (while (not (eobp))
	 (ange-ftp-put-hash-entry
	  (buffer-substring (point)
			    (progn
			      (skip-chars-forward "^ /\n")
			      (point)))
	  (eq (following-char) ?/)
	  tbl)
	 (forward-line 1))
       (ange-ftp-put-hash-entry "." t tbl)
       (ange-ftp-put-hash-entry ".." t tbl)
       tbl)))

;; Parse the current buffer which is assumed to be in a dired-like listing
;; format, and return a hashtable as the result. If the listing is not really
;; a listing, then return nil.

(defun ange-ftp-parse-dired-listing (&optional switches)
  (save-match-data
    (cond
     ((looking-at "^total [0-9]+$")
      (forward-line 1)
      ;; Some systems put in a blank line here.
      (if (eolp) (forward-line 1))
      (ange-ftp-ls-parser))
     ((looking-at "[^\n]+\\( not found\\|: Not a directory\\)\n\\'")
      ;; It's an ls error message.
      nil)
     ((eobp) ; i.e. (zerop (buffer-size))
      ;; This could be one of:
      ;; (1) An Ultrix ls error message
      ;; (2) A listing with the A switch of an empty directory
      ;;     on a machine which doesn't give a total line.
      ;; (3) The twilight zone.
      ;; We'll assume (1) for now.
      nil)
     ((re-search-forward ange-ftp-date-regexp nil t)
      (beginning-of-line)
      (ange-ftp-ls-parser))
     ((re-search-forward "^[^ \n\t]+ +\\([0-9]+\\|-\\|=\\) " nil t)
      ;; It's a dl listing (I hope).
      ;; file is bound by the call to ange-ftp-ls
      (ange-ftp-add-dl-dir ange-ftp-this-file)
      (beginning-of-line)
      (ange-ftp-dl-parser))
     (t nil))))

(defun ange-ftp-set-files (directory files)
  "For a given DIRECTORY, set or change the associated FILES hashtable."
  (and files (ange-ftp-put-hash-entry (file-name-as-directory directory)
				      files ange-ftp-files-hashtable)))

(defun ange-ftp-get-files (directory &optional no-error)
  "Given a given DIRECTORY, return a hashtable of file entries.
This will give an error or return nil, depending on the value of
NO-ERROR, if a listing for DIRECTORY cannot be obtained."
  (setq directory (file-name-as-directory directory)) ;normalize
  (or (ange-ftp-get-hash-entry directory ange-ftp-files-hashtable)
      (save-match-data
	(and (ange-ftp-ls directory
			  ;; This is an efficiency hack. We try to
			  ;; anticipate what sort of listing dired
			  ;; might want, and cache just such a listing.
			  (if (and (boundp 'dired-actual-switches)
				   (stringp dired-actual-switches)
				   ;; We allow the A switch, which lists
				   ;; all files except "." and "..".
				   ;; This is OK because we manually
				   ;; insert these entries
				   ;; in the hash table.
				   (string-match
				    "[aA]" dired-actual-switches)
				   (string-match
				    "l" dired-actual-switches)
				   (not (string-match
					 "R" dired-actual-switches)))
			      dired-actual-switches
			    (if (and (boundp 'dired-listing-switches)
				     (stringp dired-listing-switches)
				     (string-match
				      "[aA]" dired-listing-switches)
				     (string-match
				      "l" dired-listing-switches)
				     (not (string-match
					   "R" dired-listing-switches)))
				dired-listing-switches
			      "-al"))
			  t no-error)
	     (ange-ftp-get-hash-entry
	      directory ange-ftp-files-hashtable)))))

;; Given NAME, return the file part that can be used for looking up the
;; file's entry in a hashtable.
(defmacro ange-ftp-get-file-part (name)
  (` (let ((file (file-name-nondirectory (, name))))
       (if (string-equal file "")
	   "."
	 file))))

;; Return whether ange-ftp-file-entry-p and ange-ftp-get-file-entry are
;; allowed to determine if NAME is a sub-directory by listing it directly,
;; rather than listing its parent directory. This is used for efficiency so
;; that a wasted listing is not done:
;; 1. When looking for a .dired file in dired-x.el.
;; 2. The syntax of FILE and DIR make it impossible that FILE could be a valid
;;     subdirectory. This is of course an OS dependent judgement.

(defmacro ange-ftp-allow-child-lookup (dir file)
  (` (not
      (let* ((efile (, file)) ; expand once.
	     (edir (, dir))
	     (parsed (ange-ftp-ftp-name edir))
	     (host-type (ange-ftp-host-type
			 (car parsed))))
	(or
	 ;; Deal with dired
	 (and (boundp 'dired-local-variables-file) ; in the dired-x package
	      (stringp dired-local-variables-file)
	      (string-equal dired-local-variables-file efile))
	 ;; No dots in dir names in vms.
	 (and (eq host-type 'vms)
	      (string-match "\\." efile))
	 ;; No subdirs in mts of cms.
	 (and (memq host-type '(mts cms))
	      (not (string-equal "/" (nth 2 parsed)))))))))

(defun ange-ftp-file-entry-p (name)
  "Given NAME, return whether there is a file entry for it."
  (let* ((name (directory-file-name name))
	 (dir (file-name-directory name))
	 (ent (ange-ftp-get-hash-entry dir ange-ftp-files-hashtable))
	 (file (ange-ftp-get-file-part name)))
    (if ent
	(ange-ftp-hash-entry-exists-p file ent)
      (or (and (ange-ftp-allow-child-lookup dir file)
	       (setq ent (ange-ftp-get-files name t))
	       ;; Try a child lookup. i.e. try to list file as a
	       ;; subdirectory of dir. This is a good idea because
	       ;; we may not have read permission for file's parent. Also,
	       ;; people tend to work down directory trees anyway. We use
	       ;; no-error ;; because if file does not exist as a subdir.,
	       ;; then dumb hosts will give an ftp error. Smart unix hosts
	       ;; will simply send back the ls
	       ;; error message.
	       (ange-ftp-get-hash-entry "." ent))
	  ;; Child lookup failed, so try the parent.
	  (let ((table (ange-ftp-get-files dir)))
	    ;; If the dir doesn't exist, don't use it as a hash table.
	    (and table
		 (ange-ftp-hash-entry-exists-p file
					       table)))))))

(defun ange-ftp-get-file-entry (name)
  "Given NAME, return the given file entry.
The entry will be either t for a directory, nil for a normal file,
or a string for a symlink. If the file isn't in the hashtable,
this also returns nil."
  (let* ((name (directory-file-name name))
	 (dir (file-name-directory name))
	 (ent (ange-ftp-get-hash-entry dir ange-ftp-files-hashtable))
	 (file (ange-ftp-get-file-part name)))
    (if ent
	(ange-ftp-get-hash-entry file ent)
      (or (and (ange-ftp-allow-child-lookup dir file)
	       (setq ent (ange-ftp-get-files name t))
	       (ange-ftp-get-hash-entry "." ent))
	       ;; i.e. it's a directory by child lookup
	  (ange-ftp-get-hash-entry file
				   (ange-ftp-get-files dir))))))

(defun ange-ftp-internal-delete-file-entry (name &optional dir-p)
  (if dir-p
      (progn 
	(setq name (file-name-as-directory name))
	(ange-ftp-del-hash-entry name ange-ftp-files-hashtable)
	(setq name (directory-file-name name))))
  ;; Note that file-name-as-directory followed by directory-file-name
  ;; serves to canonicalize directory file names to their unix form.
  ;; i.e. in VMS, FOO.DIR -> FOO/ -> FOO
  (let ((files (ange-ftp-get-hash-entry (file-name-directory name)
					ange-ftp-files-hashtable)))
    (if files
	(ange-ftp-del-hash-entry (ange-ftp-get-file-part name)
				 files))))

(defun ange-ftp-internal-add-file-entry (name &optional dir-p)
  (and dir-p
       (setq name (directory-file-name name)))
  (let ((files (ange-ftp-get-hash-entry (file-name-directory name)
					ange-ftp-files-hashtable)))
    (if files
	(ange-ftp-put-hash-entry (ange-ftp-get-file-part name)
				 dir-p
				 files))))

(defun ange-ftp-wipe-file-entries (host user)
  "Get rid of entry for HOST, USER pair from file entry information hashtable."
  (let ((new-tbl (ange-ftp-make-hashtable (length ange-ftp-files-hashtable))))
    (ange-ftp-map-hashtable
     (function
      (lambda (key val)
	(let ((parsed (ange-ftp-ftp-name key)))
	  (if parsed
	      (let ((h (nth 0 parsed))
		    (u (nth 1 parsed)))
		(or (and (equal host h) (equal user u))
		    (ange-ftp-put-hash-entry key val new-tbl)))))))
     ange-ftp-files-hashtable)
    (setq ange-ftp-files-hashtable new-tbl)))

;;;; ------------------------------------------------------------
;;;; File transfer mode support.
;;;; ------------------------------------------------------------

(defun ange-ftp-set-binary-mode (host user)
  "Tell the ftp process for the given HOST & USER to switch to binary mode."
  (let ((result (ange-ftp-send-cmd host user '(type "binary"))))
    (if (not (car result))
	(ange-ftp-error host user (concat "BINARY failed: " (cdr result)))
      (save-excursion
	(set-buffer (process-buffer (ange-ftp-get-process host user)))
	(and ange-ftp-binary-hash-mark-size
	     (setq ange-ftp-hash-mark-unit
		   (ash ange-ftp-binary-hash-mark-size -4)))))))

(defun ange-ftp-set-ascii-mode (host user)
  "Tell the ftp process for the given HOST & USER to switch to ascii mode."
  (let ((result (ange-ftp-send-cmd host user '(type "ascii"))))
    (if (not (car result))
	(ange-ftp-error host user (concat "ASCII failed: " (cdr result)))
      (save-excursion
	(set-buffer (process-buffer (ange-ftp-get-process host user)))
	(and ange-ftp-ascii-hash-mark-size
	     (setq ange-ftp-hash-mark-unit
		   (ash ange-ftp-ascii-hash-mark-size -4)))))))

(defun ange-ftp-cd (host user dir)
  (let ((result (ange-ftp-send-cmd host user (list 'cd dir) "Doing CD")))
    (or (car result)
	(ange-ftp-error host user (concat "CD failed: " (cdr result))))))

(defun ange-ftp-get-pwd (host user)
  "Attempts to get the current working directory for the given HOST/USER pair.
Returns \( DIR . LINE \) where DIR is either the directory or nil if not found,
and LINE is the relevant success or fail line from the FTP-client."
  (let* ((result (ange-ftp-send-cmd host user '(pwd) "Getting PWD"))
	 (line (cdr result))
	 dir)
    (if (car result)
	(save-match-data
	  (and (or (string-match "\"\\([^\"]*\\)\"" line)
		   (string-match " \\([^ ]+\\) " line)) ; stone-age VMS servers!
	       (setq dir (substring line
				    (match-beginning 1)
				    (match-end 1))))))
    (cons dir line)))

;;; ------------------------------------------------------------
;;; expand-file-name and friends...which currently don't work
;;; ------------------------------------------------------------

(defun ange-ftp-expand-dir (host user dir)
  "Return the result of doing a PWD in the current FTP session.
Use the connection to machine HOST
logged in as user USER and cd'd to directory DIR."
  (let* ((host-type (ange-ftp-host-type host user))
	 ;; It is more efficient to call ange-ftp-host-type
	 ;; before binding res, because ange-ftp-host-type sometimes
	 ;; adds to the info in the expand-dir-hashtable.
	 (fix-name-func
	  (cdr (assq host-type ange-ftp-fix-name-func-alist)))
	 (key (concat host "/" user "/" dir))
	 (res (ange-ftp-get-hash-entry key ange-ftp-expand-dir-hashtable)))
    (or res
	(progn
	  (or
	   (string-equal user "anonymous")
	   (string-equal user "ftp")
	   (not (eq host-type 'unix))
	   (let* ((ange-ftp-good-msgs (concat ange-ftp-expand-dir-regexp
					      "\\|"
					      ange-ftp-good-msgs))
		  (result (ange-ftp-send-cmd host user
					     (list 'get dir null-device)
					     (format "expanding %s" dir)))
		  (line (cdr result)))
	     (setq res
		   (if (string-match ange-ftp-expand-dir-regexp line)
		       (substring line 
				  (match-beginning 1)
				  (match-end 1))))))
	  (or res
	      (if (string-equal dir "~")
		  (setq res (car (ange-ftp-get-pwd host user)))
		(let ((home (ange-ftp-expand-dir host user "~")))
		  (unwind-protect
		      (and (ange-ftp-cd host user dir)
			   (setq res (car (ange-ftp-get-pwd host user))))
		    (ange-ftp-cd host user home)))))
	  (if res
	      (let ((ange-ftp-this-user user)
		    (ange-ftp-this-host host))
		(if fix-name-func
		    (setq res (funcall fix-name-func res 'reverse)))
		(ange-ftp-put-hash-entry
		 key res ange-ftp-expand-dir-hashtable)))
	  res))))

(defun ange-ftp-canonize-filename (n)
  "Take a string and short-circuit //, /. and /.."
  (if (string-match "[^:]+//" n)		;don't upset Apollo users
      (setq n (substring n (1- (match-end 0)))))
  (let ((parsed (ange-ftp-ftp-name n)))
    (if parsed
	(let ((host (car parsed))
	      (user (nth 1 parsed))
	      (name (nth 2 parsed)))
	  
	  ;; See if remote name is absolute.  If so then just expand it and
	  ;; replace the name component of the overall name.
	  (cond ((string-match "^/" name)
		 name)
		
		;; Name starts with ~ or ~user.  Resolve that part of the name
		;; making it absolute then re-expand it.
		((string-match "^~[^/]*" name)
		 (let* ((tilda (substring name
					  (match-beginning 0) 
					  (match-end 0)))
			(rest (substring name (match-end 0)))
			(dir (ange-ftp-expand-dir host user tilda)))
		   (if dir
		       (setq name (concat dir rest))
		     (error "User \"%s\" is not known" 
			    (substring tilda 1)))))
		
		;; relative name.  Tack on homedir and re-expand.
		(t
		 (let ((dir (ange-ftp-expand-dir host user "~")))
		   (if dir
		       (setq name (concat
				   (ange-ftp-real-file-name-as-directory dir)
				   name))
		     (error "Unable to obtain CWD")))))
	  
	  ;; If name starts with //, preserve that, for apollo system.
	  (if (not (string-match "^//" name))
	      (progn
		(if (not (eq system-type 'windows-nt))
		    (setq name (ange-ftp-real-expand-file-name name))
		  ;; Windows UNC default dirs do not make sense for ftp.
		  (if (string-match "^//" default-directory)
		      (setq name (ange-ftp-real-expand-file-name name "c:/"))
		    (setq name (ange-ftp-real-expand-file-name name)))
		  ;; Strip off possible drive specifier.
		  (if (string-match "^[a-zA-Z]:" name)
		      (setq name (substring name 2))))
		(if (string-match "^//" name)
		    (setq name (substring name 1)))))
	  
	  ;; Now substitute the expanded name back into the overall filename.
	  (ange-ftp-replace-name-component n name))
      
      ;; non-ange-ftp name.  Just expand normally.
      (if (eq (string-to-char n) ?/)
	  (ange-ftp-real-expand-file-name n)
	(ange-ftp-real-expand-file-name
	 (ange-ftp-real-file-name-nondirectory n)
	 (ange-ftp-real-file-name-directory n))))))

(defun ange-ftp-expand-file-name (name &optional default)
  "Documented as original."
  (save-match-data
    (setq default (or default default-directory))
    (cond ((eq (string-to-char name) ?~)
	   (ange-ftp-real-expand-file-name name))
	  ((eq (string-to-char name) ?/)
	   (ange-ftp-canonize-filename name))
	  ((and (eq system-type 'windows-nt)
		(eq (string-to-char name) ?\\))
	   (ange-ftp-canonize-filename name))
	  ((and (eq system-type 'windows-nt)
		(or (string-match "^[a-zA-Z]:" name)
		    (string-match "^[a-zA-Z]:" default)))
	   (ange-ftp-real-expand-file-name name default))
	  ((zerop (length name))
	   (ange-ftp-canonize-filename default))
	  ((ange-ftp-canonize-filename
	    (concat (file-name-as-directory default) name))))))

;;; These are problems--they are currently not enabled.

(defvar ange-ftp-file-name-as-directory-alist nil
  "Association list of \( TYPE \. FUNC \) pairs.
FUNC converts a filename to a directory name for the operating
system TYPE.")

(defun ange-ftp-file-name-as-directory (name)
  "Documented as original."
  (let ((parsed (ange-ftp-ftp-name name)))
    (if parsed
	(if (string-equal (nth 2 parsed) "")
	    name
	  (funcall (or (cdr (assq
			     (ange-ftp-host-type (car parsed))
			     ange-ftp-file-name-as-directory-alist))
		       'ange-ftp-real-file-name-as-directory)
		   name))
      (ange-ftp-real-file-name-as-directory name))))
 	
(defun ange-ftp-file-name-directory (name)
  "Documented as original."
  (let ((parsed (ange-ftp-ftp-name name)))
    (if parsed
	(let ((filename (nth 2 parsed)))
	  (if (save-match-data
		(string-match "^~[^/]*$" filename))
	      name
	    (ange-ftp-replace-name-component
	     name
	     (ange-ftp-real-file-name-directory filename))))
      (ange-ftp-real-file-name-directory name))))

(defun ange-ftp-file-name-nondirectory (name)
  "Documented as original."
  (let ((parsed (ange-ftp-ftp-name name)))
    (if parsed
	(let ((filename (nth 2 parsed)))
	  (if (save-match-data
		(string-match "^~[^/]*$" filename))
	      ""
	    (ange-ftp-real-file-name-nondirectory name)))
      (ange-ftp-real-file-name-nondirectory name))))

(defun ange-ftp-directory-file-name (dir)
  "Documented as original."
  (let ((parsed (ange-ftp-ftp-name dir)))
    (if parsed
	(ange-ftp-replace-name-component
	   dir
	   (ange-ftp-real-directory-file-name (nth 2 parsed)))
      (ange-ftp-real-directory-file-name dir))))


;;; Hooks that handle Emacs primitives.

;; Returns non-nil if should transfer FILE in binary mode.
(defun ange-ftp-binary-file (file)
  (save-match-data
    (string-match ange-ftp-binary-file-name-regexp file)))

(defun ange-ftp-write-region (start end filename &optional append visit)
  (setq filename (expand-file-name filename))
  (let ((parsed (ange-ftp-ftp-name filename)))
    (if parsed
	(let* ((host (nth 0 parsed))
	       (user (nth 1 parsed))
	       (name (ange-ftp-quote-string (nth 2 parsed)))
	       (temp (ange-ftp-make-tmp-name host))
	       ;; What we REALLY need here is a way to determine if the mode
	       ;; of the transfer is irrelevant, i.e. we can use binary mode
	       ;; regardless. Maybe a system-type to host-type lookup?
	       (binary (or (ange-ftp-binary-file filename)
			   (memq (ange-ftp-host-type host user)
				 '(unix dumb-unix))))
	       (cmd (if append 'append 'put))
	       (abbr (ange-ftp-abbreviate-filename filename))
	       ;; we need to reset `last-coding-system-used' to its
	       ;; value immediately after calling the real write-region,
	       ;; so that `basic-save-buffer' doesn't see whatever value
	       ;; might be used when communicating with the ftp process.
	       (coding-system-used last-coding-system-used))
	  (unwind-protect
	      (progn
		(let ((executing-kbd-macro t)
		      (filename (buffer-file-name))
		      (mod-p (buffer-modified-p)))
		  (unwind-protect
		      (ange-ftp-real-write-region start end temp nil visit)
		    ;; cleanup forms
		    (setq buffer-file-name filename)
		    (set-buffer-modified-p mod-p)))
		;; save value used by the real write-region
		(setq coding-system-used last-coding-system-used)
		(if binary
		    (ange-ftp-set-binary-mode host user))

		;; tell the process filter what size the transfer will be.
		(let ((attr (file-attributes temp)))
		  (if attr
		      (ange-ftp-set-xfer-size host user (nth 7 attr))))

		;; put or append the file.
		(let ((result (ange-ftp-send-cmd host user
						 (list cmd temp name)
						 (format "Writing %s" abbr))))
		  (or (car result)
		      (signal 'ftp-error
			      (list
			       "Opening output file"
			       (format "FTP Error: \"%s\"" (cdr result))
			       filename)))))
	    (ange-ftp-del-tmp-name temp)
	    (if binary 
		(ange-ftp-set-ascii-mode host user)))
	  (if (eq visit t)
	      (progn
		(set-visited-file-modtime '(0 0))
		(ange-ftp-set-buffer-mode)
		(setq buffer-file-name filename)
		(set-buffer-modified-p nil)))
	  ;; ensure `last-coding-system-used' has an appropriate value
	  (setq last-coding-system-used coding-system-used)
	  (ange-ftp-message "Wrote %s" abbr)
	  (ange-ftp-add-file-entry filename))
      (ange-ftp-real-write-region start end filename append visit))))

(defun ange-ftp-insert-file-contents (filename &optional visit beg end replace)
  (barf-if-buffer-read-only)
  (setq filename (expand-file-name filename))
  (let ((parsed (ange-ftp-ftp-name filename)))
    (if parsed
	(progn
	  (if visit
	      (setq buffer-file-name filename))
	  (if (or (file-exists-p filename)
		  (progn
		    (setq ange-ftp-ls-cache-file nil)
		    (ange-ftp-del-hash-entry (file-name-directory filename)
					     ange-ftp-files-hashtable)
		    (file-exists-p filename)))
	      (let* ((host (nth 0 parsed))
		     (user (nth 1 parsed))
		     (name (ange-ftp-quote-string (nth 2 parsed)))
		     (temp (ange-ftp-make-tmp-name host))
		     (binary (or (ange-ftp-binary-file filename)
				 (memq (ange-ftp-host-type host user)
				       '(unix dumb-unix))))
		     (abbr (ange-ftp-abbreviate-filename filename))
		     (coding-system-used last-coding-system-used)
		     size)
		(unwind-protect
		    (progn
		      (if binary
			  (ange-ftp-set-binary-mode host user))
		      (let ((result (ange-ftp-send-cmd host user
					      (list 'get name temp)
					      (format "Retrieving %s" abbr))))
			(or (car result)
			    (signal 'ftp-error
				    (list
				     "Opening input file"
				     (format "FTP Error: \"%s\"" (cdr result))
				     filename))))
		      (if (or (ange-ftp-real-file-readable-p temp)
			      (sleep-for ange-ftp-retry-time)
			      ;; Wait for file to hopefully appear.
			      (ange-ftp-real-file-readable-p temp))
			  (setq
			   size
			   (nth 1 (ange-ftp-real-insert-file-contents
				   temp visit beg end replace))
			   coding-system-used last-coding-system-used
			   ;; override autodetection of buffer file type
			   ;; to ensure buffer is saved in DOS format
			   buffer-file-type binary)
			(signal 'ftp-error
				(list
				 "Opening input file:"
				 (format
				  "FTP Error: %s not arrived or readable"
				  filename)))))
		  (if binary
		      (ange-ftp-set-ascii-mode host user))
		  (ange-ftp-del-tmp-name temp))
		(if visit
		    (progn
		      (set-visited-file-modtime '(0 0))
		      (setq buffer-file-name filename)))
		(setq last-coding-system-used coding-system-used)
		(list filename size))
	    (signal 'file-error
		    (list 
		     "Opening input file"
		     filename))))
      (ange-ftp-real-insert-file-contents filename visit beg end replace))))
 
(defun ange-ftp-expand-symlink (file dir)
  (if (file-name-absolute-p file)
      (ange-ftp-replace-name-component dir file)
    (expand-file-name file dir)))

(defun ange-ftp-file-symlink-p (file)
  ;; call ange-ftp-expand-file-name rather than the normal
  ;; expand-file-name to stop loops when using a package that
  ;; redefines both file-symlink-p and expand-file-name.
  (setq file (ange-ftp-expand-file-name file))
  (if (ange-ftp-ftp-name file)
      (let ((file-ent
	     (ange-ftp-get-hash-entry
	      (ange-ftp-get-file-part file)
	      (ange-ftp-get-files (file-name-directory file)))))
	(if (stringp file-ent)
	    (if (file-name-absolute-p file-ent)
		(ange-ftp-replace-name-component
		      (file-name-directory file) file-ent)
	      file-ent)))
    (ange-ftp-real-file-symlink-p file)))

(defun ange-ftp-file-exists-p (name)
  (setq name (expand-file-name name))
  (if (ange-ftp-ftp-name name)
      (if (ange-ftp-file-entry-p name)
	  (let ((file-ent (ange-ftp-get-file-entry name)))
	    (if (stringp file-ent)
		(file-exists-p
		 (ange-ftp-expand-symlink file-ent
					  (file-name-directory
					   (directory-file-name name))))
	      t)))
    (ange-ftp-real-file-exists-p name)))

(defun ange-ftp-file-directory-p (name)
  (setq name (expand-file-name name))
  (if (ange-ftp-ftp-name name)
      ;; We do a file-name-as-directory on name here because some
      ;; machines (VMS) use a .DIR to indicate the filename associated
      ;; with a directory. This needs to be canonicalized.
      (let ((file-ent (ange-ftp-get-file-entry
		       (ange-ftp-file-name-as-directory name))))
	(if (stringp file-ent)
	    (file-directory-p
	     (ange-ftp-expand-symlink file-ent
				      (file-name-directory
				       (directory-file-name name))))
	  file-ent))
    (ange-ftp-real-file-directory-p name)))

(defun ange-ftp-directory-files (directory &optional full match
					   &rest v19-args)
  (setq directory (expand-file-name directory))
  (if (ange-ftp-ftp-name directory)
      (progn
	(ange-ftp-barf-if-not-directory directory)
	(let ((tail (ange-ftp-hash-table-keys
		     (ange-ftp-get-files directory)))
	      files f)
	  (setq directory (file-name-as-directory directory))
	  (save-match-data
	    (while tail
	      (setq f (car tail)
		    tail (cdr tail))
	      (if (or (not match) (string-match match f))
		  (setq files
			(cons (if full (concat directory f) f) files)))))
	  (nreverse files)))
    (apply 'ange-ftp-real-directory-files directory full match v19-args)))

(defun ange-ftp-file-attributes (file)
  (setq file (expand-file-name file))
  (let ((parsed (ange-ftp-ftp-name file)))
    (if parsed
	(let ((part (ange-ftp-get-file-part file))
	      (files (ange-ftp-get-files (file-name-directory file))))
	  (if (ange-ftp-hash-entry-exists-p part files)
	      (let ((host (nth 0 parsed))
		    (user (nth 1 parsed))
		    (name (nth 2 parsed))
		    (dirp (ange-ftp-get-hash-entry part files))
		    (inode (ange-ftp-get-hash-entry
			    file ange-ftp-inodes-hashtable)))
		(unless inode
		  (setq inode ange-ftp-next-inode-number
			ange-ftp-next-inode-number (1+ inode))
		  (ange-ftp-put-hash-entry file inode ange-ftp-inodes-hashtable))
		(list (if (and (stringp dirp) (file-name-absolute-p dirp))
			  (ange-ftp-expand-symlink dirp
						   (file-name-directory file))
			dirp)		;0 file type
		      -1		;1 link count
		      -1		;2 uid
		      -1		;3 gid
		      '(0 0)		;4 atime
		      '(0 0)		;5 mtime
		      '(0 0)		;6 ctime
		      -1		;7 size
		      (concat (if (stringp dirp) "l" (if dirp "d" "-"))
			      "?????????") ;8 mode
		      nil		;9 gid weird
		      inode		;10 "inode number".
		      -1		;11 device number [v19 only]
		      ))))
      (ange-ftp-real-file-attributes file))))

(defun ange-ftp-file-writable-p (file)
  (setq file (expand-file-name file))
  (if (ange-ftp-ftp-name file)
      (or (file-exists-p file)		;guess here for speed
	  (file-directory-p (file-name-directory file)))
    (ange-ftp-real-file-writable-p file)))

(defun ange-ftp-file-readable-p (file)
  (setq file (expand-file-name file))
  (if (ange-ftp-ftp-name file)
      (file-exists-p file)
    (ange-ftp-real-file-readable-p file)))

(defun ange-ftp-file-executable-p (file)
  (setq file (expand-file-name file))
  (if (ange-ftp-ftp-name file)
      (file-exists-p file)
    (ange-ftp-real-file-executable-p file)))

(defun ange-ftp-delete-file (file)
  (interactive "fDelete file: ")
  (setq file (expand-file-name file))
  (let ((parsed (ange-ftp-ftp-name file)))
    (if parsed
	(let* ((host (nth 0 parsed))
	       (user (nth 1 parsed))
	       (name