glob - 100% Perl implementation of (t)csh ``globbing''
On the command-line:
glob 'eenie{meenie,mynie,moe}*.[ch]'
As a Perl function:
use FastGlob qw(glob); @list = &glob('eenie{meenie,mynie,moe}*.[ch]');
The glob command/function implements globbing in perl, rather than forking a csh
like Perl's built-in glob()
call. This is faster than the
built-in glob()
call, and more robust (on many platforms, csh
chokes on echo *
if too many files are in the directory.)
The expressions that are passed as arguments to glob must adhere to csh/tcsh pattern-matching syntax for wildcard filename expansion (also known as globbing). Unquoted words containing an asterisk (*), question-mark (?), square-brackets ([...]), or curly-braces ({...}), or beginning with a tilde (~), are expanded into an alphabetically sorted list of filenames, as follows:
Match any (zero or more) characters.
Match any single character.
Match any single character in the given character class. The character
class is the enclosed list(s)
or range(s).
A list
is a string of characters. A range is two characters separated by a dash
(-), and includes all the characters in between the two characters given
(inclusive). If a dash (-) is intended to be part of the character class it
must be the first character given.
Expand the given ``word-set'' to each string (or filename-matching pattern)
in the comma-separated list. Unlike the pattern-matching expressions above,
the expansion of this construct is not sorted. For instance, {foo,bar}
expands to foo bar
(not bar foo
). As special cases, unmatched { and }, and the ``empty set'' (the string
{}) are treated as ordinary characters instead of pattern-matching
meta-characters. A backslash (\) may be used to escape an opening or
closing curly brace, or the backslash character itself. Note that word-sets may be nested!
The home directory of the invoking user as indicated by the value of the
variable $HOME
.
The home directory of the user whose login name is 'username', as indicated by the password entry for the named user.
Only the patterns *, ? and [...] imply pattern matching; an error results if no filename matches a pattern that contains them. When a period or ``dot'' (.) is the first character in a filename or pathname component, it must be matched explicitly. The filename component separator character (e.g., / or slash) must also be matched explicitly.
When invoking glob as a script from the command-line, if the very first argument is -0 (a minus sign followed by the number zero), then a NUL character (``\0'') is used to separate the expanded words and/or filenames when printing them to standard output. Otherwise a newline is used as the word/filename output separator.
When invoking glob as a function from the FastGlob
module, There are several module-local variables that can be set for
alternate environments, they are listed below with their (UNIX-ish)
defaults.
$FastGlob::dirsep = '/'; # directory path separator $FastGlob::rootpat = '\A\Z'; # root directory prefix pattern $FastGlob::curdir = '.'; # name of current directory in dir $FastGlob::parentdir = '..'; # name of parent directory in dir $FastGlob::hidedotfiles = 1; # hide filenames starting with .
So for MS-DOS for example, you could set these to:
$FastGlob::dirsep = '\\'; # directory path separator $FastGlob::rootpat = '[A-Z]:'; # <Drive letter><colon> pattern $FastGlob::curdir = '.'; # name of current directory in dir $FastGlob::parentdir = '..'; # name of parent directory in dir
$FastGlob::hidedotfiles = 0; # hide filenames starting with .
And for MacOS to:
$FastGlob::dirsep = ':'; # directory path separator $FastGlob::rootpat = '\A\Z'; # root directory prefix pattern $FastGlob::curdir = '.'; # name of current directory in dir $FastGlob::parentdir = '..'; # name of parent directory in dir $FastGlob::hidedotfiles = 0; # hide filenames starting with .
Furthermore, after a call to glob, the variable $FastGlob::matched
will indicate the number of valid filenames that were matched, and the
array @FastGlob::errors
well contain a (possibly empty) list of error messages.
When glob is invoked as a script from the command-line, the exit-status returned will be 0 if any files were matched or word-sets were expanded; 1 if no files/word-sets were matched/expanded; and 2 if some other kind of error occurred.
When glob is invoked as a function from the FastGlob
module, the return value will be an array of matching filenames and
expanded word-sets.
If no filenames are matched and pattern-matching characters were used (*, ?, or [...]), then an error message of ``No Match'' is issued. If a user's home directory is specified using tilde-expansion (e.g., ~username) but the corresponding username or their home directory cannot be found, then the error message ``Unknown user: username'' is issued.
NOTE that when glob is invoked as a script from the command-line then error messages are issued
by printing them to standard diagnostic output (STDERR); When glob is invoked as a function from the
FastGlob
module, then error messages are issued by storing in the
@FastGlob::errors
array.
Copyright (c) 1997-1999 Marc Mengel. All rights reserved.
This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.
Marc Mengel <mengel@fnal.gov>
Modified to use qr// (and some other minor speedups), to explode subexpressions in curly braces (a la csh -- rather than using just plain alternation), and made callable as a standalone script.