| File::Path - Create or remove directory trees |
File::Path - Create or remove directory trees
2.16 - released August 31 2018.
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 });
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 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:
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.
umask). If the directory already exists
(and thus does not need to be created), the permissions will
not be modified.
make_path to print the name of each directory
as it is created. By default nothing is printed.
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.
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. 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() 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 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.
NOTE: 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:
remove_tree to print the name of each file as
it is unlinked. By default nothing is printed.
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.
remove_tree( '/tmp', {keep_root => 1} );
remove_tree( '/tmp', {result => \my $list} );
print "unlinked $_\n" for @$list;
This is a useful alternative to the verbose key.
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() 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().
NOTE: 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
},
);
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.
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 not 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);
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.
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:
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.
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 carped about. Program execution will not be halted.
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).
path(s) specifiedmake_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.
make_path gives you this warning, it may mean that
you have exceeded your filesystem's maximum path length.
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.
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.
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.
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.
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.
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.
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.
The solution is to chdir out of the child directory to a place
outside the directory tree to be removed.
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.
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.
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.
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.
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.
remove_tree was unable to
restore its permissions from a permissive state back to a possibly
more restrictive setting. (Permissions given in octal).
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.
remove_tree failed to remove a file. Probably a permissions issue.
remove_tree was also unable
to restore the permissions on the file to a possibly less permissive
setting. (Permissions given in octal).
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.
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.
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.
When removing directory trees, if you want to examine each file to decide whether to delete it (and possibly leaving large swathes alone), File::Find::Rule offers a convenient and flexible approach to examining directory trees.
The following describes File::Path limitations and how to report bugs.
File::Path 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
File::Path::Tiny module for functionality similar to File::Path but which does
not chdir.
File::Path 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 File::Path to perform operations, it is strongly suggested you assure filesystem availability by reading the root of the mounted filesystem.
Please report all bugs on the RT queue, either via the web interface:
http://rt.cpan.org/NoAuth/Bugs.html
or by email:
bug-File-Path@rt.cpan.org
In either case, please attach 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
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.
Prior authors and maintainers: Tim Bunce, Charles Bailey, and David Landgren <david@landgren.net>.
Current maintainers are Richard Elberger <riche@cpan.org> and James (Jim) Keenan <jkeenan@cpan.org>.
Contributors to File::Path, in alphabetical order by first name.
This module is copyright (C) Charles Bailey, Tim Bunce, David Landgren, James Keenan and Richard Elberger 1995-2018. All rights reserved.
This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.
| File::Path - Create or remove directory trees |