Syntax-K

Know-How für Ihr Projekt

Perl Documentation

NAME

File::Glob - Perl extension for BSD glob routine

SYNOPSIS

use File::Glob ':bsd_glob';
@list = bsd_glob('*.[ch]');
$homedir = bsd_glob('~gnat', GLOB_TILDE | GLOB_ERR);
if (GLOB_ERROR) {
  # an error occurred reading $homedir
}
## override the core glob (CORE::glob() does this automatically
## by default anyway, since v5.6.0)
use File::Glob ':globally';
my @sources = <*.{c,h,y}>;
## override the core glob, forcing case sensitivity
use File::Glob qw(:globally :case);
my @sources = <*.{c,h,y}>;
## override the core glob forcing case insensitivity
use File::Glob qw(:globally :nocase);
my @sources = <*.{c,h,y}>;
## glob on all files in home directory
use File::Glob ':globally';
my @sources = <~gnat/*>;

DESCRIPTION

The glob angle-bracket operator <> is a pathname generator that implements the rules for file name pattern matching used by Unix-like shells such as the Bourne shell or C shell.

File::Glob::bsd_glob() implements the FreeBSD glob(3) routine, which is a superset of the POSIX glob() (described in IEEE Std 1003.2 "POSIX.2"). bsd_glob() takes a mandatory pattern argument, and an optional flags argument, and returns a list of filenames matching the pattern, with interpretation of the pattern modified by the flags variable.

Since v5.6.0, Perl's CORE::glob() is implemented in terms of bsd_glob(). Note that they don't share the same prototype--CORE::glob() only accepts a single argument. Due to historical reasons, CORE::glob() will also split its argument on whitespace, treating it as multiple patterns, whereas bsd_glob() considers them as one pattern. But see :bsd_glob under "EXPORTS", below.

META CHARACTERS

\       Quote the next metacharacter
[]      Character class
{}      Multiple pattern
*       Match any string of characters
?       Match any single character
~       User name home directory

The metanotation a{b,c,d}e is a shorthand for abe ace ade. Left to right order is preserved, with results of matches being sorted separately at a low level to preserve this order. As a special case {, }, and {} are passed undisturbed.

EXPORTS

See also the "POSIX FLAGS" below, which can be exported individually.

:bsd_glob

The :bsd_glob export tag exports bsd_glob() and the constants listed below. It also overrides glob() in the calling package with one that behaves like bsd_glob() with regard to spaces (the space is treated as part of a file name), but supports iteration in scalar context; i.e., it preserves the core function's feature of returning the next item each time it is called.

:glob

The :glob tag, now discouraged, is the old version of :bsd_glob. It exports the same constants and functions, but its glob() override does not support iteration; it returns the last file name in scalar context. That means this will loop forever:

use File::Glob ':glob';
while (my $file = <* copy.txt>) {
	...
}

bsd_glob

This function, which is included in the two export tags listed above, takes one or two arguments. The first is the glob pattern. The second is a set of flags ORed together. The available flags are listed below under "POSIX FLAGS". If the second argument is omitted, GLOB_CSH (or GLOB_CSH|GLOB_NOCASE on VMS and DOSish systems) is used by default.

:nocase and :case

These two export tags globally modify the default flags that bsd_glob() and, except on VMS, Perl's built-in glob operator use. GLOB_NOCASE is turned on or off, respectively.

csh_glob

The csh_glob() function can also be exported, but you should not use it directly unless you really know what you are doing. It splits the pattern into words and feeds each one to bsd_glob(). Perl's own glob() function uses this internally.

POSIX FLAGS

The POSIX defined flags for bsd_glob() are:

The FreeBSD extensions to the POSIX standard are the following flags:

The POSIX provided GLOB_APPEND, GLOB_DOOFFS, and the FreeBSD extensions GLOB_ALTDIRFUNC, and GLOB_MAGCHAR flags have not been implemented in the Perl version because they involve more complex interaction with the underlying C structures.

The following flag has been added in the Perl implementation for csh compatibility:

DIAGNOSTICS

bsd_glob() returns a list of matching paths, possibly zero length. If an error occurred, &File::Glob::GLOB_ERROR will be non-zero and $! will be set. &File::Glob::GLOB_ERROR is guaranteed to be zero if no error occurred, or one of the following values otherwise:

In the case where bsd_glob() has found some matching paths, but is interrupted by an error, it will return a list of filenames and set &File::Glob::ERROR.

Note that bsd_glob() deviates from POSIX and FreeBSD glob(3) behaviour by not considering ENOENT and ENOTDIR as errors - bsd_glob() will continue processing despite those errors, unless the GLOB_ERR flag is set.

Be aware that all filenames returned from File::Glob are tainted.

NOTES

SEE ALSO

"glob" in perlfunc, glob(3)

AUTHOR

The Perl interface was written by Nathan Torkington <gnat@frii.com>, and is released under the artistic license. Further modifications were made by Greg Bacon <gbacon@cs.uah.edu>, Gurusamy Sarathy <gsar@activestate.com>, and Thomas Wegner <wegner_thomas@yahoo.com>. The C glob code has the following copyright:

Copyright (c) 1989, 1993 The Regents of the University of California. All rights reserved.

This code is derived from software contributed to Berkeley by Guido van Rossum.

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

  1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.

  2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.

  3. Neither the name of the University nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.