xref: /openbsd-src/gnu/usr.bin/perl/lib/File/Basename.pm (revision 04bf48b9e2bc58227ac0da17f40089433d4f734e)
1package File::Basename;
2
3=head1 NAME
4
5fileparse - split a pathname into pieces
6
7basename - extract just the filename from a path
8
9dirname - extract just the directory from a path
10
11=head1 SYNOPSIS
12
13    use File::Basename;
14
15    ($name,$path,$suffix) = fileparse($fullname,@suffixlist);
16    $name = fileparse($fullname,@suffixlist);
17    fileparse_set_fstype($os_string);
18    $basename = basename($fullname,@suffixlist);
19    $dirname = dirname($fullname);
20
21    ($name,$path,$suffix) = fileparse("lib/File/Basename.pm",qr{\.pm});
22    fileparse_set_fstype("VMS");
23    $basename = basename("lib/File/Basename.pm",".pm");
24    $dirname = dirname("lib/File/Basename.pm");
25
26=head1 DESCRIPTION
27
28These routines allow you to parse file specifications into useful
29pieces using the syntax of different operating systems.
30
31=over 4
32
33=item fileparse_set_fstype
34
35You select the syntax via the routine fileparse_set_fstype().
36
37If the argument passed to it contains one of the substrings
38"VMS", "MSDOS", "MacOS", "AmigaOS" or "MSWin32", the file specification
39syntax of that operating system is used in future calls to
40fileparse(), basename(), and dirname().  If it contains none of
41these substrings, Unix syntax is used.  This pattern matching is
42case-insensitive.  If you've selected VMS syntax, and the file
43specification you pass to one of these routines contains a "/",
44they assume you are using Unix emulation and apply the Unix syntax
45rules instead, for that function call only.
46
47If the argument passed to it contains one of the substrings "VMS",
48"MSDOS", "MacOS", "AmigaOS", "os2", "MSWin32" or "RISCOS", then the pattern
49matching for suffix removal is performed without regard for case,
50since those systems are not case-sensitive when opening existing files
51(though some of them preserve case on file creation).
52
53If you haven't called fileparse_set_fstype(), the syntax is chosen
54by examining the builtin variable C<$^O> according to these rules.
55
56=item fileparse
57
58The fileparse() routine divides a file specification into three
59parts: a leading B<path>, a file B<name>, and a B<suffix>.  The
60B<path> contains everything up to and including the last directory
61separator in the input file specification.  The remainder of the input
62file specification is then divided into B<name> and B<suffix> based on
63the optional patterns you specify in C<@suffixlist>.  Each element of
64this list can be a qr-quoted pattern (or a string which is interpreted
65as a regular expression), and is matched
66against the end of B<name>.  If this succeeds, the matching portion of
67B<name> is removed and prepended to B<suffix>.  By proper use of
68C<@suffixlist>, you can remove file types or versions for examination.
69
70You are guaranteed that if you concatenate B<path>, B<name>, and
71B<suffix> together in that order, the result will denote the same
72file as the input file specification.
73
74In scalar context, fileparse() returns only the B<name> part of the filename.
75
76=back
77
78=head1 EXAMPLES
79
80Using Unix file syntax:
81
82    ($base,$path,$type) = fileparse('/virgil/aeneid/draft.book7',
83				    qr{\.book\d+});
84
85would yield
86
87    $base eq 'draft'
88    $path eq '/virgil/aeneid/',
89    $type eq '.book7'
90
91Similarly, using VMS syntax:
92
93    ($name,$dir,$type) = fileparse('Doc_Root:[Help]Rhetoric.Rnh',
94				   qr{\..*});
95
96would yield
97
98    $name eq 'Rhetoric'
99    $dir  eq 'Doc_Root:[Help]'
100    $type eq '.Rnh'
101
102=over
103
104=item C<basename>
105
106The basename() routine returns the first element of the list produced
107by calling fileparse() with the same arguments, except that it always
108quotes metacharacters in the given suffixes.  It is provided for
109programmer compatibility with the Unix shell command basename(1).
110
111=item C<dirname>
112
113The dirname() routine returns the directory portion of the input file
114specification.  When using VMS or MacOS syntax, this is identical to the
115second element of the list produced by calling fileparse() with the same
116input file specification.  (Under VMS, if there is no directory information
117in the input file specification, then the current default device and
118directory are returned.)  When using Unix or MSDOS syntax, the return
119value conforms to the behavior of the Unix shell command dirname(1).  This
120is usually the same as the behavior of fileparse(), but differs in some
121cases.  For example, for the input file specification F<lib/>, fileparse()
122considers the directory name to be F<lib/>, while dirname() considers the
123directory name to be F<.>).
124
125=back
126
127=cut
128
129
130## use strict;
131# A bit of juggling to insure that C<use re 'taint';> always works, since
132# File::Basename is used during the Perl build, when the re extension may
133# not be available.
134BEGIN {
135  unless (eval { require re; })
136    { eval ' sub re::import { $^H |= 0x00100000; } ' } # HINT_RE_TAINT
137  import re 'taint';
138}
139
140
141
142use 5.006;
143use warnings;
144our(@ISA, @EXPORT, $VERSION, $Fileparse_fstype, $Fileparse_igncase);
145require Exporter;
146@ISA = qw(Exporter);
147@EXPORT = qw(fileparse fileparse_set_fstype basename dirname);
148$VERSION = "2.73";
149
150
151#   fileparse_set_fstype() - specify OS-based rules used in future
152#                            calls to routines in this package
153#
154#   Currently recognized values: VMS, MSDOS, MacOS, AmigaOS, os2, RISCOS
155#       Any other name uses Unix-style rules and is case-sensitive
156
157sub fileparse_set_fstype {
158  my @old = ($Fileparse_fstype, $Fileparse_igncase);
159  if (@_) {
160    $Fileparse_fstype = $_[0];
161    $Fileparse_igncase = ($_[0] =~ /^(?:MacOS|VMS|AmigaOS|os2|RISCOS|MSWin32|MSDOS)/i);
162  }
163  wantarray ? @old : $old[0];
164}
165
166#   fileparse() - parse file specification
167#
168#   Version 2.4  27-Sep-1996  Charles Bailey  bailey@genetics.upenn.edu
169
170
171sub fileparse {
172  my($fullname,@suffices) = @_;
173  unless (defined $fullname) {
174      require Carp;
175      Carp::croak("fileparse(): need a valid pathname");
176  }
177  my($fstype,$igncase) = ($Fileparse_fstype, $Fileparse_igncase);
178  my($dirpath,$tail,$suffix,$basename);
179  my($taint) = substr($fullname,0,0);  # Is $fullname tainted?
180
181  if ($fstype =~ /^VMS/i) {
182    if ($fullname =~ m#/#) { $fstype = '' }  # We're doing Unix emulation
183    else {
184      ($dirpath,$basename) = ($fullname =~ /^(.*[:>\]])?(.*)/s);
185      $dirpath ||= '';  # should always be defined
186    }
187  }
188  if ($fstype =~ /^MS(DOS|Win32)|epoc/i) {
189    ($dirpath,$basename) = ($fullname =~ /^((?:.*[:\\\/])?)(.*)/s);
190    $dirpath .= '.\\' unless $dirpath =~ /[\\\/]\z/;
191  }
192  elsif ($fstype =~ /^os2/i) {
193    ($dirpath,$basename) = ($fullname =~ m#^((?:.*[:\\/])?)(.*)#s);
194    $dirpath = './' unless $dirpath;	# Can't be 0
195    $dirpath .= '/' unless $dirpath =~ m#[\\/]\z#;
196  }
197  elsif ($fstype =~ /^MacOS/si) {
198    ($dirpath,$basename) = ($fullname =~ /^(.*:)?(.*)/s);
199    $dirpath = ':' unless $dirpath;
200  }
201  elsif ($fstype =~ /^AmigaOS/i) {
202    ($dirpath,$basename) = ($fullname =~ /(.*[:\/])?(.*)/s);
203    $dirpath = './' unless $dirpath;
204  }
205  elsif ($fstype !~ /^VMS/i) {  # default to Unix
206    ($dirpath,$basename) = ($fullname =~ m#^(.*/)?(.*)#s);
207    if ($^O eq 'VMS' and $fullname =~ m:^(/[^/]+/000000(/|$))(.*):) {
208      # dev:[000000] is top of VMS tree, similar to Unix '/'
209      # so strip it off and treat the rest as "normal"
210      my $devspec  = $1;
211      my $remainder = $3;
212      ($dirpath,$basename) = ($remainder =~ m#^(.*/)?(.*)#s);
213      $dirpath ||= '';  # should always be defined
214      $dirpath = $devspec.$dirpath;
215    }
216    $dirpath = './' unless $dirpath;
217  }
218
219  if (@suffices) {
220    $tail = '';
221    foreach $suffix (@suffices) {
222      my $pat = ($igncase ? '(?i)' : '') . "($suffix)\$";
223      if ($basename =~ s/$pat//s) {
224        $taint .= substr($suffix,0,0);
225        $tail = $1 . $tail;
226      }
227    }
228  }
229
230  $tail .= $taint if defined $tail; # avoid warning if $tail == undef
231  wantarray ? ($basename .= $taint, $dirpath .= $taint, $tail)
232            : ($basename .= $taint);
233}
234
235
236#   basename() - returns first element of list returned by fileparse()
237
238sub basename {
239  my($name) = shift;
240  (fileparse($name, map("\Q$_\E",@_)))[0];
241}
242
243
244#    dirname() - returns device and directory portion of file specification
245#        Behavior matches that of Unix dirname(1) exactly for Unix and MSDOS
246#        filespecs except for names ending with a separator, e.g., "/xx/yy/".
247#        This differs from the second element of the list returned
248#        by fileparse() in that the trailing '/' (Unix) or '\' (MSDOS) (and
249#        the last directory name if the filespec ends in a '/' or '\'), is lost.
250
251sub dirname {
252    my($basename,$dirname) = fileparse($_[0]);
253    my($fstype) = $Fileparse_fstype;
254
255    if ($fstype =~ /VMS/i) {
256        if ($_[0] =~ m#/#) { $fstype = '' }
257        else { return $dirname || $ENV{DEFAULT} }
258    }
259    if ($fstype =~ /MacOS/i) {
260	if( !length($basename) && $dirname !~ /^[^:]+:\z/) {
261	    $dirname =~ s/([^:]):\z/$1/s;
262	    ($basename,$dirname) = fileparse $dirname;
263	}
264	$dirname .= ":" unless $dirname =~ /:\z/;
265    }
266    elsif ($fstype =~ /MS(DOS|Win32)|os2/i) {
267        $dirname =~ s/([^:])[\\\/]*\z/$1/;
268        unless( length($basename) ) {
269	    ($basename,$dirname) = fileparse $dirname;
270	    $dirname =~ s/([^:])[\\\/]*\z/$1/;
271	}
272    }
273    elsif ($fstype =~ /AmigaOS/i) {
274        if ( $dirname =~ /:\z/) { return $dirname }
275        chop $dirname;
276        $dirname =~ s#[^:/]+\z## unless length($basename);
277    }
278    else {
279        $dirname =~ s:(.)/*\z:$1:s;
280        unless( length($basename) ) {
281	    local($File::Basename::Fileparse_fstype) = $fstype;
282	    ($basename,$dirname) = fileparse $dirname;
283	    $dirname =~ s:(.)/*\z:$1:s;
284	}
285    }
286
287    $dirname;
288}
289
290fileparse_set_fstype $^O;
291
2921;
293