Table of Contents generated with DocToc
- 25 Zftp Function System
25 Zftp Function System
25.1 Description
This describes the set of shell functions supplied with the source
distribution as an interface to the zftp
builtin command, allowing you
to perform FTP operations from the shell command line or within
functions or scripts. The interface is similar to a traditional FTP
client (e.g. the ftp
command itself, see man page ftp(1)), but as it
is entirely done within the shell all the familiar completion, editing
and globbing features, and so on, are present, and macros are
particularly simple to write as they are just ordinary shell functions.
The prerequisite is that the zftp
command, as described in The
zsh/zftp Module , must be
available in the version of zsh
installed at your site. If the shell
is configured to load new commands at run time, it probably is: typing
‘zmodload zsh/zftp
’ will make sure (if that runs silently, it has
worked). If this is not the case, it is possible zftp
was linked into
the shell anyway: to test this, type ‘which zftp
’ and if zftp
is
available you will get the message ‘zftp: shell built-in command
’.
Commands given directly with zftp
builtin may be interspersed between
the functions in this suite; in a few cases, using zftp
directly may
cause some of the status information stored in shell parameters to
become invalid. Note in particular the description of the variables
$ZFTP_TMOUT
, $ZFTP_PREFS
and $ZFTP_VERBOSE
for zftp
.
25.2 Installation
You should make sure all the functions from the Functions/Zftp
directory of the source distribution are available; they all begin with
the two letters ‘zf
’. They may already have been installed on your
system; otherwise, you will need to find them and copy them. The
directory should appear as one of the elements of the $fpath
array
(this should already be the case if they were installed), and at least
the function zfinit
should be autoloaded; it will autoload the rest.
Finally, to initialize the use of the system you need to call the
zfinit
function. The following code in your .zshrc
will arrange for
this; assume the functions are stored in the directory ~/myfns
:
fpath=(~/myfns $fpath)
autoload -U zfinit
zfinit
Note that zfinit
assumes you are using the zmodload
method to load
the zftp
command. If it is already built into the shell, change
zfinit
to zfinit -n
. It is helpful (though not essential) if the
call to zfinit
appears after any code to initialize the new completion
system, else unnecessary compctl
commands will be given.
25.3 Functions
The sequence of operations in performing a file transfer is essentially
the same as that in a standard FTP client. Note that, due to a quirk of
the shell’s getopts
builtin, for those functions that handle options
you must use ‘-``-
’ rather than ‘-
’ to ensure the remaining
arguments are treated literally (a single ‘-
’ is treated as an
argument).
25.3.1 Opening a connection
zfparams
[ host
[ user
[ password
... ] ] ]
Set or show the parameters for a future zfopen
with no arguments. If
no arguments are given, the current parameters are displayed (the
password will be shown as a line of asterisks). If a host
is given,
and either the user
or password
is not, they will be prompted for;
also, any parameter given as ‘?
’ will be prompted for, and if the
‘?
’ is followed by a string, that will be used as the prompt. As
zfopen
calls zfparams
to store the parameters, this usually need not
be called directly.
A single argument ‘-
’ will delete the stored parameters. This will
also cause the memory of the last directory (and so on) on the other
host to be deleted.
zfopen
[ -1
] [ host
[ user
[ password
[ account
] ]
] ]
If host
is present, open a connection to that host under username
user
with password password
(and, on the rare occasions when it is
necessary, account account
). If a necessary parameter is missing or
given as ‘?
’ it will be prompted for. If host
is not present, use a
previously stored set of parameters.
If the command was successful, and the terminal is compatible with
xterm
or is sun-cmd
, a summary will appear in the title bar, giving
the local host:directory
and the remote host:directory
; this is
handled by the function zftp_chpwd
, described below.
Normally, the host
, user
and password
are internally recorded for
later re-opening, either by a zfopen
with no arguments, or
automatically (see below). With the option ‘-1
’, no information is
stored. Also, if an open command with arguments failed, the parameters
will not be retained (and any previous parameters will also be deleted).
A zfopen
on its own, or a zfopen -1
, never alters the stored
parameters.
Both zfopen
and zfanon
(but not zfparams
) understand URLs of the
form ftp://``host
/path...
as meaning to connect to the host
, then
change directory to path
(which must be a directory, not a file). The
‘ftp://
’ can be omitted; the trailing ‘/
’ is enough to trigger
recognition of the path
. Note prefixes other than ‘ftp:
’ are not
recognized, and that all characters after the first slash beyond host
are significant in path
.
zfanon
[ -1
] host
Open a connection host
for anonymous FTP. The username used is
‘anonymous
’. The password (which will be reported the first time) is
generated as user``@``host
; this is then stored in the shell parameter
$EMAIL_ADDR
which can alternatively be set manually to a
25.3.2 Directory management
zfcd
[ dir
]
zfcd -
zfcd
old
new
Change the current directory on the remote server: this is implemented
to have many of the features of the shell builtin cd
.
In the first form with dir
present, change to the directory dir
. The
command ‘zfcd ..
’ is treated specially, so is guaranteed to work on
non-UNIX servers (note this is handled internally by zftp
). If dir
is omitted, has the effect of ‘zfcd ~
’.
The second form changes to the directory previously current.
The third form attempts to change the current directory by replacing the
first occurrence of the string old
with the string new
in the
current directory.
Note that in this command, and indeed anywhere a remote filename is
expected, the string which on the local host corresponds to ‘~
’ is
converted back to a ‘~
’ before being passed to the remote machine.
This is convenient because of the way expansion is performed on the
command line before zfcd
receives a string. For example, suppose the
command is ‘zfcd ~/foo
’. The shell will expand this to a full path
such as ‘zfcd /home/user2/pws/foo
’. At this stage, zfcd
recognises
the initial path as corresponding to ‘~
’ and will send the directory
to the remote host as ~/foo
, so that the ‘~
’ will be expanded by the
server to the correct remote host directory. Other named directories of
the form ‘~name
’ are not treated in this fashion.
zfhere
Change directory on the remote server to the one corresponding to the
current local directory, with special handling of ‘~
’ as in zfcd
.
For example, if the current local directory is ~/foo/bar
, then
zfhere
performs the effect of ‘zfcd ~/foo/bar
’.
zfdir
[ -rfd
] [ -
] [ dir-options
] [ dir
]
Produce a long directory listing. The arguments dir-options
and dir
are passed directly to the server and their effect is implementation
dependent, but specifying a particular remote directory dir
is usually
possible. The output is passed through a pager given by the environment
variable $PAGER
, or ‘more
’ if that is not set.
The directory is usually cached for re-use. In fact, two caches are
maintained. One is for use when there is no dir-options
or dir
, i.e.
a full listing of the current remote directory; it is flushed when the
current remote directory changes. The other is kept for repeated use of
zfdir
with the same arguments; for example, repeated use of ‘zfdir /pub/gnu
’ will only require the directory to be retrieved on the first
call. Alternatively, this cache can be re-viewed with the -r
option.
As relative directories will confuse zfdir
, the -f
option can be
used to force the cache to be flushed before the directory is listed.
The option -d
will delete both caches without showing a directory
listing; it will also delete the cache of file names in the current
remote directory, if any.
zfls
[ ls-options
] [ dir
]
List files on the remote server. With no arguments, this will produce a simple list of file names for the current remote directory. Any arguments are passed directly to the server. No pager and no caching is used.
25.3.3 Status commands
zftype
[ type
]
With no arguments, show the type of data to be transferred, usually
ASCII or binary. With an argument, change the type: the types ‘A
’ or
‘ASCII
’ for ASCII data and ‘B
’ or ‘BINARY
’, ‘I
’ or ‘IMAGE
’
for binary data are understood case-insensitively.
zfstat
[ -v
]
Show the status of the current or last connection, as well as the status
of some of zftp
’s status variables. With the -v
option, a more
verbose listing is produced by querying the server for its version of
events, too.
25.3.4 Retrieving files
The commands for retrieving files all take at least two options. -G
suppresses remote filename expansion which would otherwise be performed
(see below for a more detailed description of that). -t
attempts to
set the modification time of the local file to that of the remote file:
see the description of the function zfrtime
below for more
information.
zfget
[ -Gtc
] file1
...
Retrieve all the listed files file1
... one at a time from the remote
server. If a file contains a ‘/
’, the full name is passed to the
remote server, but the file is stored locally under the name given by
the part after the final ‘/
’. The option -c
(cat) forces all files
to be sent as a single stream to standard output; in this case the -t
option has no effect.
zfuget
[ -Gvst
] file1
...
As zfget
, but only retrieve files where the version on the remote
server is newer (has a later modification time), or where the local file
does not exist. If the remote file is older but the files have different
sizes, or if the sizes are the same but the remote file is newer, the
user will usually be queried. With the option -s
, the command runs
silently and will always retrieve the file in either of those two cases.
With the option -v
, the command prints more information about the
files while it is working out whether or not to transfer them.
zfcget
[ -Gt
] file1
...
As zfget
, but if any of the local files exists, and is shorter than
the corresponding remote file, the command assumes that it is the result
of a partially completed transfer and attempts to transfer the rest of
the file. This is useful on a poor connection which keeps failing.
Note that this requires a commonly implemented, but non-standard, version of the FTP protocol, so is not guaranteed to work on all servers.
zfgcp
[ -Gt
] remote-file
local-file
zfgcp
[ -Gt
] rfile1
... ldir
This retrieves files from the remote server with arguments behaving
similarly to the cp
command.
In the first form, copy remote-file
from the server to the local file
local-file
.
In the second form, copy all the remote files rfile1
... into the
local directory ldir
retaining the same basenames. This assumes UNIX
directory semantics.
25.3.5 Sending files
zfput
[ -r
] file1
...
Send all the file1
... given separately to the remote server. If a
filename contains a ‘/
’, the full filename is used locally to find the
file, but only the basename is used for the remote file name.
With the option -r
, if any of the files
are directories they are
sent recursively with all their subdirectories, including files
beginning with ‘.
’. This requires that the remote machine understand
UNIX file semantics, since ‘/
’ is used as a directory separator.
zfuput
[ -vs
] file1
...
As zfput
, but only send files which are newer than their remote
equivalents, or if the remote file does not exist. The logic is the same
as for zfuget
, but reversed between local and remote files.
zfcput
file1
...
As zfput
, but if any remote file already exists and is shorter than
the local equivalent, assume it is the result of an incomplete transfer
and send the rest of the file to append to the existing part. As the FTP
append command is part of the standard set, this is in principle more
likely to work than zfcget
.
zfpcp
local-file
remote-file
zfpcp
lfile1
... rdir
This sends files to the remote server with arguments behaving similarly
to the cp
command.
With two arguments, copy local-file
to the server as remote-file
.
With more than two arguments, copy all the local files lfile1
... into
the existing remote directory rdir
retaining the same basenames. This
assumes UNIX directory semantics.
A problem arises if you attempt to use zfpcp
lfile1
rdir
, i.e. the
second form of copying but with two arguments, as the command has no
simple way of knowing if rdir
corresponds to a directory or a
filename. It attempts to resolve this in various ways. First, if the
rdir
argument is ‘.
’ or ‘..
’ or ends in a slash, it is assumed to
be a directory. Secondly, if the operation of copying to a remote file
in the first form failed, and the remote server sends back the expected
failure code 553 and a reply including the string ‘Is a directory
’,
then zfpcp
will retry using the second form.
25.3.6 Closing the connection
zfclose
Close the connection.
25.3.7 Session management
zfsession
[ -lvod
] [ sessname
]
Allows you to manage multiple FTP sessions at once. By default,
connections take place in a session called ‘default
’; by giving the
command ‘zfsession
sessname
’ you can change to a new or existing
session with a name of your choice. The new session remembers its own
connection, as well as associated shell parameters, and also the
host/user parameters set by zfparams
. Hence you can have different
sessions set up to connect to different hosts, each remembering the
appropriate host, user and password.
With no arguments, zfsession
prints the name of the current session;
with the option -l
it lists all sessions which currently exist, and
with the option -v
it gives a verbose list showing the host and
directory for each session, where the current session is marked with an
asterisk. With -o
, it will switch to the most recent previous session.
With -d
, the given session (or else the current one) is removed;
everything to do with it is completely forgotten. If it was the only
session, a new session called ‘default
’ is created and made current.
It is safest not to delete sessions while background commands using
zftp
are active.
zftransfer
sess1``:``file1
sess2``:``file2
Transfer files between two sessions; no local copy is made. The file is
read from the session sess1
as file1
and written to session sess2
as file file2
; file1
and file2
may be relative to the current
directories of the session. Either sess1
or sess2
may be omitted
(though the colon should be retained if there is a possibility of a
colon appearing in the file name) and defaults to the current session;
file2
may be omitted or may end with a slash, in which case the
basename of file1
will be added. The sessions sess1
and sess2
must
be distinct.
The operation is performed using pipes, so it is required that the connections still be valid in a subshell, which is not the case under versions of some operating systems, presumably due to a system bug.
25.3.8 Bookmarks
The two functions zfmark
and zfgoto
allow you to ‘bookmark’ the
present location (host, user and directory) of the current FTP
connection for later use. The file to be used for storing and retrieving
bookmarks is given by the parameter $ZFTP_BMFILE
; if not set when one
of the two functions is called, it will be set to the file .zfbkmarks
in the directory where your zsh startup files live (usually ~
).
zfmark
[ bookmark
]
If given an argument, mark the current host, user and directory under
the name bookmark
for later use by zfgoto
. If there is no connection
open, use the values for the last connection immediately before it was
closed; it is an error if there was none. Any existing bookmark under
the same name will be silently replaced.
If not given an argument, list the existing bookmarks and the points to
which they refer in the form user``@``host``:``directory
; this is the
format in which they are stored, and the file may be edited directly.
zfgoto
[ -n
] bookmark
Return to the location given by bookmark
, as previously set by
zfmark
. If the location has user ‘ftp
’ or ‘anonymous
’, open the
connection with zfanon
, so that no password is required. If the user
and host parameters match those stored for the current session, if any,
those will be used, and again no password is required. Otherwise a
password will be prompted for.
With the option -n
, the bookmark is taken to be a nickname stored by
the ncftp
program in its bookmark file, which is assumed to be
~/.ncftp/bookmarks
. The function works identically in other ways. Note
that there is no mechanism for adding or modifying ncftp
bookmarks
from the zftp functions.
25.3.9 Other functions
Mostly, these functions will not be called directly (apart from
zfinit
), but are described here for completeness. You may wish to
alter zftp_chpwd
and zftp_progress
, in particular.
zfinit
[ -n
]
As described above, this is used to initialize the zftp function system.
The -n
option should be used if the zftp command is already built into
the shell.
zfautocheck
[ -dn
]
This function is called to implement automatic reopening behaviour, as
described in more detail below. The options must appear in the first
argument; -n
prevents the command from changing to the old directory,
while -d
prevents it from setting the variable do_close
, which it
otherwise does as a flag for automatically closing the connection after
a transfer. The host and directory for the last session are stored in
the variable $zflastsession
, but the internal host/user/password
parameters must also be correctly set.
zfcd_match prefix suffix
This performs matching for completion of remote directory names. If the
remote server is UNIX, it will attempt to persuade the server to list
the remote directory with subdirectories marked, which usually works but
is not guaranteed. On other hosts it simply calls zfget_match
and
hence completes all files, not just directories. On some systems,
directories may not even look like filenames.
zfget_match prefix suffix
This performs matching for completion of remote filenames. It caches
files for the current directory (only) in the shell parameter
$zftp_fcache
. It is in the form to be called by the -K
option of
compctl
, but also works when called from a widget-style completion
function with prefix
and suffix
set appropriately.
zfrglob varname
Perform remote globbing, as describes in more detail below. varname
is
the name of a variable containing the pattern to be expanded; if there
were any matches, the same variable will be set to the expanded set of
filenames on return.
zfrtime
lfile
rfile
[ time
]
Set the local file lfile
to have the same modification time as the
remote file rfile
, or the explicit time time
in FTP format
CCYYMMDDhhmmSS
for the GMT timezone. This uses the shell’s
zsh/datetime
module to perform the conversion from GMT to local time.
zftp_chpwd
This function is called every time a connection is opened, or closed, or
the remote directory changes. This version alters the title bar of an
xterm
-compatible or sun-cmd
terminal emulator to reflect the local
and remote hostnames and current directories. It works best when
combined with the function chpwd
. In particular, a function of the
form
chpwd() {
if [[ -n $ZFTP_USER ]]; then
zftp_chpwd
else
# usual chpwd e.g put host:directory in title bar
fi
}
fits in well.
zftp_progress
This function shows the status of the transfer. It will not write
anything unless the output is going to a terminal; however, if you
transfer files in the background, you should turn off progress reports
by hand using ‘zstyle ’:zftp:*’ progress none
’. Note also that if you
alter it, any output must be to standard error, as standard output may
be a file being received. The form of the progress meter, or whether it
is used at all, can be configured without altering the function, as
described in the next section.
zffcache
This is used to implement caching of files in the current directory for
each session separately. It is used by zfget_match
and zfrglob
.
25.4 Miscellaneous Features
25.4.1 Configuration
Various styles are available using the standard shell style mechanism,
described in The zsh/zutil
Module. Briefly, the command
‘zstyle ’:zftp:*’
style
value
...’. defines the style
to have
value value
; more than one value may be given, although that is not
useful in the cases described here. These values will then be used
throughout the zftp function system. For more precise control, the first
argument, which gives a context in which the style applies, can be
modified to include a particular function, as for example
‘:zftp:zfget
’: the style will then have the given value only in
the zfget
function. Values for the same style in different contexts
may be set; the most specific function will be used, where strings are
held to be more specific than patterns, and longer patterns and shorter
patterns. Note that only the top level function name, as called by the
user, is used; calling of lower level functions is transparent to the
user. Hence modifications to the title bar in zftp_chpwd
use the
contexts :zftp:zfopen
, :zftp:zfcd
, etc., depending where it was
called from. The following styles are understood:
progress
Controls the way that zftp_progress
reports on the progress of a
transfer. If empty, unset, or ‘none
’, no progress report is made; if
‘bar
’ a growing bar of inverse video is shown; if ‘percent
’ (or
any other string, though this may change in future), the percentage of
the file transferred is shown. The bar meter requires that the width of
the terminal be available via the $COLUMNS
parameter (normally this is
set automatically). If the size of the file being transferred is not
available, bar
and percent
meters will simply show the number of
bytes transferred so far.
When zfinit
is run, if this style is not defined for the context
:zftp:*
, it will be set to ‘bar’.
update
Specifies the minimum time interval between updates of the progress
meter in seconds. No update is made unless new data has been received,
so the actual time interval is limited only by $ZFTP_TIMEOUT
.
As described for progress
, zfinit
will force this to default to 1.
remote-glob
If set to ‘1
’, ‘yes
’ or ‘true
’, filename generation (globbing) is
performed on the remote machine instead of by zsh itself; see below.
titlebar
If set to ‘1
’, ‘yes
’ or ‘true
’, zftp_chpwd
will put the remote
host and remote directory into the titlebar of terminal emulators such
as xterm or sun-cmd that allow this.
As described for progress
, zfinit
will force this to default to 1.
chpwd
If set to ‘1
’ ‘yes
’ or ‘true
’, zftp_chpwd
will call the function
chpwd
when a connection is closed. This is useful if the remote host
details were put into the terminal title bar by zftp_chpwd
and your
usual chpwd
also modifies the title bar.
When zfinit
is run, it will determine whether chpwd
exists and if so
it will set the default value for the style to 1 if none exists already.
Note that there is also an associative array zfconfig
which contains
values used by the function system. This should not be modified or
overwritten.
25.4.2 Remote globbing
The commands for retrieving files usually perform filename generation
(globbing) on their arguments; this can be turned off by passing the
option -G
to each of the commands. Normally this operates by
retrieving a complete list of files for the directory in question, then
matching these locally against the pattern supplied. This has the
advantage that the full range of zsh patterns (respecting the setting of
the option EXTENDED_GLOB
) can be used. However, it means that the
directory part of a filename will not be expanded and must be given
exactly. If the remote server does not support the UNIX directory
semantics, directory handling is problematic and it is recommended that
globbing only be used within the current directory. The list of files in
the current directory, if retrieved, will be cached, so that subsequent
globs in the same directory without an intervening zfcd
are much
faster.
If the remote-glob
style (see above) is set, globbing is instead
performed on the remote host: the server is asked for a list of matching
files. This is highly dependent on how the server is implemented, though
typically UNIX servers will provide support for basic glob patterns.
This may in some cases be faster, as it avoids retrieving the entire
list of directory contents.
25.4.3 Automatic and temporary reopening
As described for the zfopen
command, a subsequent zfopen
with no
parameters will reopen the connection to the last host (this includes
connections made with the zfanon
command). Opened in this fashion, the
connection starts in the default remote directory and will remain open
until explicitly closed.
Automatic re-opening is also available. If a connection is not currently
open and a command requiring a connection is given, the last connection
is implicitly reopened. In this case the directory which was current
when the connection was closed again becomes the current directory
(unless, of course, the command given changes it). Automatic reopening
will also take place if the connection was close by the remote server
for whatever reason (e.g. a timeout). It is not available if the -1
option to zfopen
or zfanon
was used.
Furthermore, if the command issued is a file transfer, the connection
will be closed after the transfer is finished, hence providing a
one-shot mode for transfers. This does not apply to directory changing
or listing commands; for example a zfdir
may reopen a connection but
will leave it open. Also, automatic closure will only ever happen in the
same command as automatic opening, i.e a zfdir
directly followed by a
zfget
will never close the connection automatically.
Information about the previous connection is given by the zfstat
function. So, for example, if that reports:
Session: default
Not connected.
Last session: ftp.bar.com:/pub/textfiles
then the command zfget file.txt
will attempt to reopen a connection to
ftp.bar.com
, retrieve the file /pub/textfiles/file.txt
, and
immediately close the connection again. On the other hand, zfcd ..
will open the connection in the directory /pub
and leave it open.
Note that all the above is local to each session; if you return to a previous session, the connection for that session is the one which will be reopened.
25.4.4 Completion
Completion of local and remote files, directories, sessions and
bookmarks is supported. The older, compctl
-style completion is defined
when zfinit
is called; support for the new widget-based completion
system is provided in the function Completion/Zsh/Command/_zftp
, which
should be installed with the other functions of the completion system
and hence should automatically be available.
This document was generated on February 15, 2020 using
texi2html 5.0.
Zsh version 5.8, released on February 14, 2020.