File::Path(3p) Perl Programmers Reference Guide File::Path(3p) #
File::Path(3p) Perl Programmers Reference Guide File::Path(3p)
NNAAMMEE #
File::Path - Create or remove directory trees
VVEERRSSIIOONN #
2.18 - released November 4 2020.
SSYYNNOOPPSSIISS #
use File::Path qw(make_path remove_tree);
@created = make_path('foo/bar/baz', '/zug/zwang');
@created = make_path('foo/bar/baz', '/zug/zwang', {
verbose => 1,
mode => 0711,
});
make_path('foo/bar/baz', '/zug/zwang', {
chmod => 0777,
});
$removed_count = remove_tree('foo/bar/baz', '/zug/zwang', {
verbose => 1,
error => \my $err_list,
safe => 1,
});
# legacy (interface promoted before v2.00)
@created = mkpath('/foo/bar/baz');
@created = mkpath('/foo/bar/baz', 1, 0711);
@created = mkpath(['/foo/bar/baz', 'blurfl/quux'], 1, 0711);
$removed_count = rmtree('foo/bar/baz', 1, 1);
$removed_count = rmtree(['foo/bar/baz', 'blurfl/quux'], 1, 1);
# legacy (interface promoted before v2.06)
@created = mkpath('foo/bar/baz', '/zug/zwang', { verbose => 1, mode => 0711 });
$removed_count = rmtree('foo/bar/baz', '/zug/zwang', { verbose => 1, mode => 0711 });
DDEESSCCRRIIPPTTIIOONN #
This module provides a convenient way to create directories of arbitrary
depth and to delete an entire directory subtree from the filesystem.
The following functions are provided:
make_path( $dir1, $dir2, .... )
make_path( $dir1, $dir2, ...., \%opts )
The "make_path" function creates the given directories if they don't
exist before, much like the Unix command "mkdir -p".
The function accepts a list of directories to be created. Its
behaviour may be tuned by an optional hashref appearing as the last
parameter on the call.
The function returns the list of directories actually created during
the call; in scalar context the number of directories created.
The following keys are recognised in the option hash:
mode => $num
The numeric permissions mode to apply to each created directory
(defaults to 0777), to be modified by the current "umask". If the
directory already exists (and thus does not need to be created),
the permissions will not be modified.
"mask" is recognised as an alias for this parameter.
chmod => $num
Takes a numeric mode to apply to each created directory (not
modified by the current "umask"). If the directory already exists
(and thus does not need to be created), the permissions will not
be modified.
verbose => $bool
If present, will cause "make_path" to print the name of each
directory as it is created. By default nothing is printed.
error => \$err
If present, it should be a reference to a scalar. This scalar
will be made to reference an array, which will be used to store
any errors that are encountered. See the "ERROR HANDLING"
section for more information.
If this parameter is not used, certain error conditions may raise
a fatal error that will cause the program to halt, unless trapped
in an "eval" block.
owner => $owner
user => $owner
uid => $owner
If present, will cause any created directory to be owned by
$owner. If the value is numeric, it will be interpreted as a
uid; otherwise a username is assumed. An error will be issued if
the username cannot be mapped to a uid, the uid does not exist or
the process lacks the privileges to change ownership.
Ownership of directories that already exist will not be changed.
"user" and "uid" are aliases of "owner".
group => $group
If present, will cause any created directory to be owned by the
group $group. If the value is numeric, it will be interpreted as
a gid; otherwise a group name is assumed. An error will be issued
if the group name cannot be mapped to a gid, the gid does not
exist or the process lacks the privileges to change group
ownership.
Group ownership of directories that already exist will not be
changed.
make_path '/var/tmp/webcache', {owner=>'nobody', group=>'nogroup'};
mkpath( $dir )
mkpath( $dir, $verbose, $mode )
mkpath( [$dir1, $dir2,...], $verbose, $mode )
mkpath( $dir1, $dir2,..., \%opt )
The "mkpath()" function provide the legacy interface of "make_path()"
with a different interpretation of the arguments passed. The
behaviour and return value of the function is otherwise identical to
"make_path()".
remove_tree( $dir1, $dir2, .... )
remove_tree( $dir1, $dir2, ...., \%opts )
The "remove_tree" function deletes the given directories and any
files and subdirectories they might contain, much like the Unix
command "rm -rf" or the Windows commands "rmdir /s" and "rd /s".
The function accepts a list of directories to be removed. (In point
of fact, it will also accept filesystem entries which are not
directories, such as regular files and symlinks. But, as its name
suggests, its intent is to remove trees rather than individual
files.)
"remove_tree()"'s behaviour may be tuned by an optional hashref
appearing as the last parameter on the call. If an empty string is
passed to "remove_tree", an error will occur.
NNOOTTEE:: For security reasons, we strongly advise use of the hashref-
as-final-argument syntax -- specifically, with a setting of the
"safe" element to a true value.
remove_tree( $dir1, $dir2, ....,
{
safe => 1,
... # other key-value pairs
},
);
The function returns the number of files successfully deleted.
The following keys are recognised in the option hash:
verbose => $bool
If present, will cause "remove_tree" to print the name of each
file as it is unlinked. By default nothing is printed.
safe => $bool
When set to a true value, will cause "remove_tree" to skip the
files for which the process lacks the required privileges needed
to delete files, such as delete privileges on VMS. In other
words, the code will make no attempt to alter file permissions.
Thus, if the process is interrupted, no filesystem object will be
left in a more permissive mode.
keep_root => $bool
When set to a true value, will cause all files and subdirectories
to be removed, except the initially specified directories. This
comes in handy when cleaning out an application's scratch
directory.
remove_tree( '/tmp', {keep_root => 1} );
result => \$res
If present, it should be a reference to a scalar. This scalar
will be made to reference an array, which will be used to store
all files and directories unlinked during the call. If nothing is
unlinked, the array will be empty.
remove_tree( '/tmp', {result => \my $list} );
print "unlinked $_\n" for @$list;
This is a useful alternative to the "verbose" key.
error => \$err
If present, it should be a reference to a scalar. This scalar
will be made to reference an array, which will be used to store
any errors that are encountered. See the "ERROR HANDLING"
section for more information.
Removing things is a much more dangerous proposition than
creating things. As such, there are certain conditions that
"remove_tree" may encounter that are so dangerous that the only
sane action left is to kill the program.
Use "error" to trap all that is reasonable (problems with
permissions and the like), and let it die if things get out of
hand. This is the safest course of action.
rmtree( $dir )
rmtree( $dir, $verbose, $safe )
rmtree( [$dir1, $dir2,...], $verbose, $safe )
rmtree( $dir1, $dir2,..., \%opt )
The "rmtree()" function provide the legacy interface of
"remove_tree()" with a different interpretation of the arguments
passed. The behaviour and return value of the function is otherwise
identical to "remove_tree()".
NNOOTTEE:: For security reasons, we strongly advise use of the hashref-
as-final-argument syntax, specifically with a setting of the "safe"
element to a true value.
rmtree( $dir1, $dir2, ....,
{
safe => 1,
... # other key-value pairs
},
);
EERRRROORR HHAANNDDLLIINNGG #
NNOOTTEE:: #
The following error handling mechanism is consistent throughout all
code paths EXCEPT in cases where the ROOT node is nonexistent. In
version 2.11 the maintainers attempted to rectify this inconsistency
but too many downstream modules encountered problems. In such case,
if you require root node evaluation or error checking prior to
calling "make_path" or "remove_tree", you should take additional
precautions.
If "make_path" or "remove_tree" encounters an error, a diagnostic message
will be printed to "STDERR" via "carp" (for non-fatal errors) or via
"croak" (for fatal errors).
If this behaviour is not desirable, the "error" attribute may be used to
hold a reference to a variable, which will be used to store the
diagnostics. The variable is made a reference to an array of hash
references. Each hash contain a single key/value pair where the key is
the name of the file, and the value is the error message (including the
contents of $! when appropriate). If a general error is encountered the
diagnostic key will be empty.
An example usage looks like:
remove_tree( 'foo/bar', 'bar/rat', {error => \my $err} );
if ($err && @$err) {
for my $diag (@$err) {
my ($file, $message) = %$diag;
if ($file eq '') {
print "general error: $message\n";
}
else {
print "problem unlinking $file: $message\n";
}
}
}
else {
print "No error encountered\n";
}
Note that if no errors are encountered, $err will reference an empty
array. This means that $err will always end up TRUE; so you need to test
@$err to determine if errors occurred.
NNOOTTEESS #
"File::Path" blindly exports "mkpath" and "rmtree" into the current
namespace. These days, this is considered bad style, but to change it now
would break too much code. Nonetheless, you are invited to specify what
it is you are expecting to use:
use File::Path 'rmtree';
The routines "make_path" and "remove_tree" are nnoott exported by default.
You must specify which ones you want to use.
use File::Path 'remove_tree';
Note that a side-effect of the above is that "mkpath" and "rmtree" are no
longer exported at all. This is due to the way the "Exporter" module
works. If you are migrating a codebase to use the new interface, you will
have to list everything explicitly. But that's just good practice anyway.
use File::Path qw(remove_tree rmtree);
_A_P_I _C_H_A_N_G_E_S #
The API was changed in the 2.0 branch. For a time, "mkpath" and "rmtree"
tried, unsuccessfully, to deal with the two different calling mechanisms.
This approach was considered a failure.
The new semantics are now only available with "make_path" and
"remove_tree". The old semantics are only available through "mkpath" and
"rmtree". Users are strongly encouraged to upgrade to at least 2.08 in
order to avoid surprises.
_S_E_C_U_R_I_T_Y _C_O_N_S_I_D_E_R_A_T_I_O_N_S #
There were race conditions in the 1.x implementations of File::Path's
"rmtree" function (although sometimes patched depending on the OS
distribution or platform). The 2.0 version contains code to avoid the
problem mentioned in CVE-2002-0435.
See the following pages for more information:
http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=286905
http://www.nntp.perl.org/group/perl.perl5.porters/2005/01/msg97623.html
http://www.debian.org/security/2005/dsa-696
Additionally, unless the "safe" parameter is set (or the third parameter
in the traditional interface is TRUE), should a "remove_tree" be
interrupted, files that were originally in read-only mode may now have
their permissions set to a read-write (or "delete OK") mode.
The following CVE reports were previously filed against File-Path and are
believed to have been addressed:
• <http://cve.circl.lu/cve/CVE-2004-0452>
• <http://cve.circl.lu/cve/CVE-2005-0448>
In February 2017 the cPanel Security Team reported an additional
vulnerability in File-Path. The "chmod()" logic to make directories
traversable can be abused to set the mode on an attacker-chosen file to
an attacker-chosen value. This is due to the time-of-check-to-time-of-
use (TOCTTOU) race condition
(<https://en.wikipedia.org/wiki/Time_of_check_to_time_of_use>) between
the "stat()" that decides the inode is a directory and the "chmod()" that
tries to make it user-rwx. CPAN versions 2.13 and later incorporate a
patch provided by John Lightsey to address this problem. This
vulnerability has been reported as CVE-2017-6512.
DDIIAAGGNNOOSSTTIICCSS #
FATAL errors will cause the program to halt ("croak"), since the problem
is so severe that it would be dangerous to continue. (This can always be
trapped with "eval", but it's not a good idea. Under the circumstances,
dying is the best thing to do).
SEVERE errors may be trapped using the modern interface. If the they are
not trapped, or if the old interface is used, such an error will cause
the program will halt.
All other errors may be trapped using the modern interface, otherwise
they will be "carp"ed about. Program execution will not be halted.
mkdir [path]: [errmsg] (SEVERE)
"make_path" was unable to create the path. Probably some sort of
permissions error at the point of departure or insufficient resources
(such as free inodes on Unix).
No root path(s) specified
"make_path" was not given any paths to create. This message is only
emitted if the routine is called with the traditional interface. The
modern interface will remain silent if given nothing to do.
No such file or directory
On Windows, if "make_path" gives you this warning, it may mean that
you have exceeded your filesystem's maximum path length.
cannot fetch initial working directory: [errmsg]
"remove_tree" attempted to determine the initial directory by calling
"Cwd::getcwd", but the call failed for some reason. No attempt will
be made to delete anything.
cannot stat initial working directory: [errmsg]
"remove_tree" attempted to stat the initial directory (after having
successfully obtained its name via "getcwd"), however, the call
failed for some reason. No attempt will be made to delete anything.
cannot chdir to [dir]: [errmsg]
"remove_tree" attempted to set the working directory in order to
begin deleting the objects therein, but was unsuccessful. This is
usually a permissions issue. The routine will continue to delete
other things, but this directory will be left intact.
directory [dir] changed before chdir, expected dev=[n] ino=[n], actual
dev=[n] ino=[n], aborting. (FATAL)
"remove_tree" recorded the device and inode of a directory, and then
moved into it. It then performed a "stat" on the current directory
and detected that the device and inode were no longer the same. As
this is at the heart of the race condition problem, the program will
die at this point.
cannot make directory [dir] read+writeable: [errmsg]
"remove_tree" attempted to change the permissions on the current
directory to ensure that subsequent unlinkings would not run into
problems, but was unable to do so. The permissions remain as they
were, and the program will carry on, doing the best it can.
cannot read [dir]: [errmsg]
"remove_tree" tried to read the contents of the directory in order to
acquire the names of the directory entries to be unlinked, but was
unsuccessful. This is usually a permissions issue. The program will
continue, but the files in this directory will remain after the call.
cannot reset chmod [dir]: [errmsg]
"remove_tree", after having deleted everything in a directory,
attempted to restore its permissions to the original state but
failed. The directory may wind up being left behind.
cannot remove [dir] when cwd is [dir]
The current working directory of the program is _/_s_o_m_e_/_p_a_t_h_/_t_o_/_h_e_r_e
and you are attempting to remove an ancestor, such as _/_s_o_m_e_/_p_a_t_h.
The directory tree is left untouched.
The solution is to "chdir" out of the child directory to a place
outside the directory tree to be removed.
cannot chdir to [parent-dir] from [child-dir]: [errmsg], aborting.
(FATAL) #
"remove_tree", after having deleted everything and restored the
permissions of a directory, was unable to chdir back to the parent.
The program halts to avoid a race condition from occurring.
cannot stat prior working directory [dir]: [errmsg], aborting. (FATAL)
"remove_tree" was unable to stat the parent directory after having
returned from the child. Since there is no way of knowing if we
returned to where we think we should be (by comparing device and
inode) the only way out is to "croak".
previous directory [parent-dir] changed before entering [child-dir],
expected dev=[n] ino=[n], actual dev=[n] ino=[n], aborting. (FATAL)
When "remove_tree" returned from deleting files in a child directory,
a check revealed that the parent directory it returned to wasn't the
one it started out from. This is considered a sign of malicious
activity.
cannot make directory [dir] writeable: [errmsg]
Just before removing a directory (after having successfully removed
everything it contained), "remove_tree" attempted to set the
permissions on the directory to ensure it could be removed and
failed. Program execution continues, but the directory may possibly
not be deleted.
cannot remove directory [dir]: [errmsg]
"remove_tree" attempted to remove a directory, but failed. This may
be because some objects that were unable to be removed remain in the
directory, or it could be a permissions issue. The directory will be
left behind.
cannot restore permissions of [dir] to [0nnn]: [errmsg]
After having failed to remove a directory, "remove_tree" was unable
to restore its permissions from a permissive state back to a possibly
more restrictive setting. (Permissions given in octal).
cannot make file [file] writeable: [errmsg]
"remove_tree" attempted to force the permissions of a file to ensure
it could be deleted, but failed to do so. It will, however, still
attempt to unlink the file.
cannot unlink file [file]: [errmsg]
"remove_tree" failed to remove a file. Probably a permissions issue.
cannot restore permissions of [file] to [0nnn]: [errmsg]
After having failed to remove a file, "remove_tree" was also unable
to restore the permissions on the file to a possibly less permissive
setting. (Permissions given in octal).
unable to map [owner] to a uid, ownership not changed");
"make_path" was instructed to give the ownership of created
directories to the symbolic name [owner], but "getpwnam" did not
return the corresponding numeric uid. The directory will be created,
but ownership will not be changed.
unable to map [group] to a gid, group ownership not changed
"make_path" was instructed to give the group ownership of created
directories to the symbolic name [group], but "getgrnam" did not
return the corresponding numeric gid. The directory will be created,
but group ownership will not be changed.
SSEEEE AALLSSOO #
• File::Remove
Allows files and directories to be moved to the Trashcan/Recycle Bin
(where they may later be restored if necessary) if the operating
system supports such functionality. This feature may one day be made
available directly in "File::Path".
• File::Find::Rule
When removing directory trees, if you want to examine each file to
decide whether to delete it (and possibly leaving large swathes
alone), _F_i_l_e_:_:_F_i_n_d_:_:_R_u_l_e offers a convenient and flexible approach to
examining directory trees.
BBUUGGSS AANNDD LLIIMMIITTAATTIIOONNSS #
The following describes _F_i_l_e_:_:_P_a_t_h limitations and how to report bugs.
MMUULLTTIITTHHRREEAADDEEDD AAPPPPLLIICCAATTIIOONNSS #
_F_i_l_e_:_:_P_a_t_h "rmtree" and "remove_tree" will not work with multithreaded
applications due to its use of "chdir". At this time, no warning or
error is generated in this situation. You will certainly encounter
unexpected results.
The implementation that surfaces this limitation will not be changed. See
the _F_i_l_e_:_:_P_a_t_h_:_:_T_i_n_y module for functionality similar to _F_i_l_e_:_:_P_a_t_h but
which does not "chdir".
NNFFSS MMoouunntt PPooiinnttss _F_i_l_e_:_:_P_a_t_h is not responsible for triggering the automounts, mirror mounts, and the contents of network mounted filesystems. If your NFS implementation requires an action to be performed on the filesystem in order for _F_i_l_e_:_:_P_a_t_h to perform operations, it is strongly suggested you assure filesystem availability by reading the root of the mounted filesystem.
RREEPPOORRTTIINNGG BBUUGGSS #
Please report all bugs on the RT queue, either via the web interface:
<http://rt.cpan.org/NoAuth/Bugs.html?Dist=File-Path>
or by email:
bug-File-Path@rt.cpan.org
In either case, please aattttaacchh patches to the bug report rather than
including them inline in the web post or the body of the email.
You can also send pull requests to the Github repository:
<https://github.com/rpcme/File-Path>
AACCKKNNOOWWLLEEDDGGEEMMEENNTTSS #
Paul Szabo identified the race condition originally, and Brendan O'Dea
wrote an implementation for Debian that addressed the problem. That code
was used as a basis for the current code. Their efforts are greatly
appreciated.
Gisle Aas made a number of improvements to the documentation for 2.07 and
his advice and assistance is also greatly appreciated.
AAUUTTHHOORRSS #
Prior authors and maintainers: Tim Bunce, Charles Bailey, and David
Landgren <_d_a_v_i_d_@_l_a_n_d_g_r_e_n_._n_e_t>.
Current maintainers are Richard Elberger <_r_i_c_h_e_@_c_p_a_n_._o_r_g> and James (Jim)
Keenan <_j_k_e_e_n_a_n_@_c_p_a_n_._o_r_g>.
CCOONNTTRRIIBBUUTTOORRSS #
Contributors to File::Path, in alphabetical order by first name.
<_b_u_l_k_d_d_@_c_p_a_n_._o_r_g>
Charlie Gonzalez <_i_t_c_h_a_r_l_i_e_@_c_p_a_n_._o_r_g>
Craig A. Berry <_c_r_a_i_g_b_e_r_r_y_@_m_a_c_._c_o_m>
James E Keenan <_j_k_e_e_n_a_n_@_c_p_a_n_._o_r_g>
John Lightsey <_j_o_h_n_@_p_e_r_l_s_e_c_._o_r_g>
Nigel Horne <_n_j_h_@_b_a_n_d_s_m_a_n_._c_o_._u_k>
Richard Elberger <_r_i_c_h_e_@_c_p_a_n_._o_r_g>
Ryan Yee <_r_y_e_e_@_c_p_a_n_._o_r_g>
Skye Shaw <_s_h_a_w_@_c_p_a_n_._o_r_g>
Tom Lutz <_t_o_m_m_y_l_u_t_z_@_g_m_a_i_l_._c_o_m>
Will Sheppard <_w_i_l_l_s_h_e_p_p_a_r_d_@_g_i_t_h_u_b>
CCOOPPYYRRIIGGHHTT #
This module is copyright (C) Charles Bailey, Tim Bunce, David Landgren,
James Keenan and Richard Elberger 1995-2020. All rights reserved.
LLIICCEENNSSEE #
This library is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.
perl v5.36.3 2023-02-15 File::Path(3p)