zsh/Doc/Zsh/mod_files.yo

COMMENT(!MOD!zsh/files
Some basic file manipulation commands as builtins.
!MOD!)
cindex(files, manipulating)
The tt(zsh/files) module makes available some common commands for file
manipulation as builtins; these commands are probably not needed for
many normal situations but can be useful in emergency recovery
situations with constrained resources.  The commands do not implement
all features now required by relevant standards committees.

For all commands, a variant beginning tt(zf_) is also available and loaded
automatically.  Using the features capability of zmodload will let you load
only those names you want.

The commands loaded by default are:

startitem()
findex(chgrp)
item(tt(chgrp) [ tt(-hRs) ] var(group) var(filename) ...)(
Changes group of files specified.  This is equivalent to tt(chown) with
a var(user-spec) argument of `tt(:)var(group)'.
)
findex(chown)
item(tt(chown) [ tt(-hRs) ] var(user-spec) var(filename) ...)(
Changes ownership and group of files specified.

The var(user-spec) can be in four forms:

startsitem()
sitem(var(user))(change owner to var(user); do not change group)
sitem(var(user)tt(::))(change owner to var(user); do not change group)
sitem(var(user)tt(:))(change owner to var(user); change group to var(user)'s primary group)
sitem(var(user)tt(:)var(group))(change owner to var(user); change group to var(group))
sitem(tt(:)var(group))(do not change owner; change group to var(group))
endsitem()

In each case, the `tt(:)' may instead be a `tt(.)'.  The rule is that
if there is a `tt(:)' then the separator is `tt(:)', otherwise
if there is a `tt(.)' then the separator is `tt(.)', otherwise
there is no separator.

Each of var(user) and var(group) may be either a username (or group name, as
appropriate) or a decimal user ID (group ID).  Interpretation as a name
takes precedence, if there is an all-numeric username (or group name).

If the target is a symbolic link, the tt(-h) option causes tt(chown) to set
the ownership of the link instead of its target.

The tt(-R) option causes tt(chown) to recursively descend into directories,
changing the ownership of all files in the directory after
changing the ownership of the directory itself.

The tt(-s) option is a zsh extension to tt(chown) functionality.  It enables
paranoid behaviour, intended to avoid security problems involving
a tt(chown) being tricked into affecting files other than the ones
intended.  It will refuse to follow symbolic links, so that (for example)
``tt(chown luser /tmp/foo/passwd)'' can't accidentally chown tt(/etc/passwd)
if tt(/tmp/foo) happens to be a link to tt(/etc).  It will also check
where it is after leaving directories, so that a recursive chown of
a deep directory tree can't end up recursively chowning tt(/usr) as
a result of directories being moved up the tree.
)
findex(ln)
xitem(tt(ln) [ tt(-dfhins) ] var(filename) var(dest))
item(tt(ln) [ tt(-dfhins) ] var(filename) ... var(dir))(
Creates hard (or, with tt(-s), symbolic) links.  In the first form, the
specified var(dest)ination is created, as a link to the specified
var(filename).  In the second form, each of the var(filename)s is
taken in turn, and linked to a pathname in the specified var(dir)ectory
that has the same last pathname component.

Normally, tt(ln) will not attempt to create hard links to
directories.  This check can be overridden using the tt(-d) option.
Typically only the super-user can actually succeed in creating
hard links to directories.
This does not apply to symbolic links in any case.

By default, existing files cannot be replaced by links.
The tt(-i) option causes the user to be queried about replacing
existing files.  The tt(-f) option causes existing files to be
silently deleted, without querying.  tt(-f) takes precedence.

The tt(-h) and tt(-n) options are identical and both exist for
compatibility; either one indicates that if the target is a symlink
then it should not be dereferenced.
Typically this is used in combination with tt(-sf) so that if an
existing link points to a directory then it will be removed,
instead of followed.
If this option is used with multiple filenames and the target
is a symbolic link pointing to a directory then the result is
an error.
)
findex(mkdir)
item(tt(mkdir) [ tt(-p) ] [ tt(-m) var(mode) ] var(dir) ...)(
Creates directories.  With the tt(-p) option, non-existing parent
directories are first created if necessary, and there will be
no complaint if the directory already exists.
The tt(-m) option can be used to specify (in octal) a set of file permissions
for the created directories, otherwise mode 777 modified by the current
tt(umask) (see manref(umask)(2)) is used.
)
findex(mv)
xitem(tt(mv) [ tt(-fi) ] var(filename) var(dest))
item(tt(mv) [ tt(-fi) ] var(filename) ... var(dir))(
Moves files.  In the first form, the specified var(filename) is moved
to the specified var(dest)ination.  In the second form, each of the
var(filename)s is
taken in turn, and moved to a pathname in the specified var(dir)ectory
that has the same last pathname component.

By default, the user will be queried before replacing any file
that the user cannot write to, but writable files will be silently
removed.
The tt(-i) option causes the user to be queried about replacing
any existing files.  The tt(-f) option causes any existing files to be
silently deleted, without querying.  tt(-f) takes precedence.

Note that this tt(mv) will not move files across devices.
Historical versions of tt(mv), when actual renaming is impossible,
fall back on copying and removing files; if this behaviour is desired,
use tt(cp) and tt(rm) manually.  This may change in a future version.
)
findex(rm)
item(tt(rm) [ tt(-dfirs) ] var(filename) ...)(
Removes files and directories specified.

Normally, tt(rm) will not remove directories (except with the tt(-r)
option).  The tt(-d) option causes tt(rm) to try removing directories
with tt(unlink) (see manref(unlink)(2)), the same method used for files.
Typically only the super-user can actually succeed in unlinking
directories in this way.
tt(-d) takes precedence over tt(-r).

By default, the user will be queried before removing any file
that the user cannot write to, but writable files will be silently
removed.
The tt(-i) option causes the user to be queried about removing
any files.  The tt(-f) option causes files to be
silently deleted, without querying, and suppresses all error indications.
tt(-f) takes precedence.

The tt(-r) option causes tt(rm) to recursively descend into directories,
deleting all files in the directory before removing the directory with
the tt(rmdir) system call (see manref(rmdir)(2)).

The tt(-s) option is a zsh extension to tt(rm) functionality.  It enables
paranoid behaviour, intended to avoid common security problems involving
a root-run tt(rm) being tricked into removing files other than the ones
intended.  It will refuse to follow symbolic links, so that (for example)
``tt(rm /tmp/foo/passwd)'' can't accidentally remove tt(/etc/passwd)
if tt(/tmp/foo) happens to be a link to tt(/etc).  It will also check
where it is after leaving directories, so that a recursive removal of
a deep directory tree can't end up recursively removing tt(/usr) as
a result of directories being moved up the tree.
)
findex(rmdir)
item(tt(rmdir) var(dir) ...)(
Removes empty directories specified.
)
findex(sync)
item(tt(sync))(
Calls the system call of the same name (see manref(sync)(2)), which
flushes dirty buffers to disk.  It might return before the I/O has
actually been completed.
)
enditem()