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NAME
File::Path - Create or remove directory trees
VERSION
This document describes version 2.09 of File::Path, released
2013-01-17.
SYNOPSIS
use File::Path qw(make_path remove_tree);
make_path('foo/bar/baz', '/zug/zwang');
make_path('foo/bar/baz', '/zug/zwang', {
verbose => 1,
mode => 0711,
});
remove_tree('foo/bar/baz', '/zug/zwang');
remove_tree('foo/bar/baz', '/zug/zwang', {
verbose => 1,
error => \my $err_list,
});
# legacy (interface promoted before v2.00)
mkpath('/foo/bar/baz');
mkpath('/foo/bar/baz', 1, 0711);
mkpath(['/foo/bar/baz', 'blurfl/quux'], 1, 0711);
rmtree('foo/bar/baz', 1, 1);
rmtree(['foo/bar/baz', 'blurfl/quux'], 1, 1);
# legacy (interface promoted before v2.06)
mkpath('foo/bar/baz', '/zug/zwang', { verbose => 1, mode => 0711 });
rmtree('foo/bar/baz', '/zug/zwang', { verbose => 1, mode => 0711 });
DESCRIPTION
This module provide 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 exists 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.
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 will 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 as username is assumed. An error will be issued
if the username cannot be mapped to a uid, or the uid does not
exist, or the process lacks the privileges to change ownership.
Ownwership 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 as group name is assumed. An error will be
issued if the group name cannot be mapped to a gid, or the gid
does not exist, or the process lacks the privileges to change
group ownership.
Group ownwership 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 -r" or "del /s" on Windows.
The function accepts a list of directories to be removed. Its
behaviour may be tuned by an optional hashref appearing as the last
parameter on the call.
The functions 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().
ERROR HANDLING
NOTE:
The following error handling mechanism is considered experimental
and is subject to change pending feedback from users.
If "make_path" or "remove_tree" encounter 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) {
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 occured.
NOTES
"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);
API CHANGES
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.
SECURITY CONSIDERATIONS
There were race conditions 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.
DIAGNOSTICS
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 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 /some/path/to/here
and you are attempting to remove an ancestor, such as /some/path.
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 have
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
because some objects that were unable to be removed remain in the
directory, or 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.
SEE ALSO
o 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".
o 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), File::Find::Rule offers a convenient and flexible approach
to examining directory trees.
BUGS
Please report all bugs on the RT queue:
<http://rt.cpan.org/NoAuth/Bugs.html?Dist=File-Path>;
You can also send pull requests to the Github repository:
<https://github.com/dland/File-Path>;
ACKNOWLEDGEMENTS
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.
AUTHORS
Tim Bunce and Charles Bailey. Currently maintained by David Landgren
<david AT landgren.net>.
COPYRIGHT
This module is copyright (C) Charles Bailey, Tim Bunce and David
Landgren 1995-2013. All rights reserved.
LICENSE
This library is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.
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