NAME
zshzftpsys - zftp function front-end
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 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
zshmodules(1) , 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.
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.
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).
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 suitable string.
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.
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.
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:
this requires version 5 of perl, 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.
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 local
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.
Closing the connection
zfclose
Close the connection.
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.
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.
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.
Currently this requires perl version 5 to perform the conversion
from GMT to local time. This is unfortunately difficult to do
using shell code alone.
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.
MISCELLANEOUS FEATURES
Configuration
Various styles are available using the standard shell style mechanism,
described in zshmodules(1). 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.
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.
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.
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.