Homepage: https://www.gnu.org/software/emacs
Author: Andy Norman
Transparent FTP support for GNU Emacs
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, connects to the host 'anorman' as
user 'ange', gets the file '/tmp/notes' and pops 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 customized to a certain
extent by changing ange-ftp-name-format. There are limitations.
The `host' part has an optional suffix `#port' which may be used to
specify a non-default port number for the connection.
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 init 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. Also, you can
set the variable ange-ftp-vms-host-regexp in your init 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$$:/ANONYMOUS/SDSCPUB/NEXT/README.TXT;1
i.e. to log in as anonymous on ymir.claremont.edu and grab the file:
[.CSV.POLICY]RULES.MEM
you would type:
C-x C-f /anonymous@ymir.claremont.edu:CSV/POLICY/RULES.MEM
A valid VMS filename is of the form: FILE.TYPE;##
where FILE can be up to 39 characters
TYPE can be up to 39 characters
## is a version number (an integer between 1 and 32,767)
Valid characters in FILE and TYPE are A-Z 0-9 _ - $
$ cannot begin a filename, and - cannot be used as the first or last
character.
Tips:
1. Although VMS is not case sensitive, EMACS running under UNIX is.
Therefore, to access a VMS file, you must enter the filename with upper
case letters.
2. To access the latest version of file under VMS, you use the filename
without the ";" and version number. You should always edit the latest
version of a file. If you want to edit an earlier version, copy it to a
new file first. This has nothing to do with ange-ftp, but is simply
good VMS operating practice. Therefore, to edit FILE.TXT;3 (say 3 is
latest version), do C-x C-f /ymir.claremont.edu:FILE.TXT. If you
inadvertently do C-x C-f /ymir.claremont.edu:FILE.TXT;3, you will find
that VMS will not allow you to save the file because it will refuse to
overwrite FILE.TXT;3, but instead will want to create FILE.TXT;4, and
attach the buffer to this file. To get out of this situation, M-x
write-file /ymir.claremont.edu:FILE.TXT will attach the buffer to
latest version of the file. For this reason, in dired "f"
(dired-find-file), always loads the file sans version, whereas "v",
(dired-view-file), always loads the explicit version number. The
reasoning being that it reasonable to view old versions of a file, but
not to edit them.
3. EMACS has a feature in which it does environment variable substitution
in filenames. Therefore, to enter a $ in a filename, you must quote it
by typing $$.
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 init 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 init 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 other words, 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.
BS2000 support:
Ange-ftp has full support for BS2000 hosts. It should be able to
automatically recognize any BS2000 machine. However, if it fails to
do this, you can use the command ange-ftp-add-bs2000-host. As well,
you can set the variable ange-ftp-bs2000-host-regexp in your .emacs
file. We would be grateful if you would report any failures to auto-
matically recognize a BS2000 host as a bug.
If you want to access the POSIX subsystem on BS2000 you MUST use
command ange-ftp-add-bs2000-posix-host for that particular
hostname. ange-ftp can't decide if you want to access the native
filesystem or the POSIX filesystem, so it accesses the native
filesystem by default. And if you have an ASCII filesystem in
your BS2000 POSIX subsystem you must use
ange-ftp-binary-file-name-regexp to access its files.
Filename Syntax:
For ease of *implementation*, the user enters the BS2000 filename
syntax in a UNIX-y way. For example:
:PUB:$PUBLIC.ANONYMOUS.SDSCPUB.NEXT.README.TXT
would be entered as:
/:PUB:/$$PUBLIC/ANONYMOUS.SDSCPUB.NEXT.README.TXT
You don't have to type pubset and account, if they have default values,
i.e. to log in as anonymous on bs2000.anywhere.com and grab the file
IMPORTANT.TEXT.ON.BS2000 on the default pubset X on userid PUBLIC
(there are only 8 characters in a valid username), you could type:
C-x C-f /public@bs2000.anywhere.com:/IMPORTANT.TEXT.ON.BS2000
or
C-x C-f /anonym@bs2000.anywhere.com:/:X:/$$PUBLIC/IMPORTANT.TEXT.ON.BS2000
If X is not your default pubset, you could add it as 'subdirectory' (BS2000
has a flat architecture) with the command
(setq ange-ftp-bs2000-additional-pubsets '(":X:"))
and then you could type:
C-x C-f /anonym@bs2000.anywhere.com:/:X:/IMPORTANT.TEXT.ON.BS2000
Valid characters in an BS2000 filename are A-Z 0-9 $ # @ . -
If the first character in a filename is # or @, this is replaced with
ange-ftp-bs2000-special-prefix because names starting with # or @
are reserved for temporary files.
This is especially important for auto-save files.
Valid file generations are ending with ([+|-|*]0-9...) .
File generations are not supported yet!
A filename must at least contain one character (A-Z) and cannot be longer
than 41 characters.
Tips:
1. Although BS2000 is not case sensitive, EMACS running under UNIX is.
Therefore, to access a BS2000 file, you must enter the filename with
upper case letters.
2. 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 $$.
3. BS2000 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.
------------------------------------------------------------------
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 report a
bug to the Emacs maintainers via M-x report-emacs-bug.
-----------------------------------------------------------
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.