1File::Spec::Mac(3) User Contributed Perl Documentation File::Spec::Mac(3)
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6 File::Spec::Mac - File::Spec for Mac OS (Classic)
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9 require File::Spec::Mac; # Done internally by File::Spec if needed
10
12 Methods for manipulating file specifications.
13
15 canonpath
16 On Mac OS, there's nothing to be done. Returns what it's given.
17 catdir()
19 Concatenate two or more directory names to form a path separated by
20 colons (":") ending with a directory. Resulting paths are relative by
21 default, but can be forced to be absolute (but avoid this, see
22 below). Automatically puts a trailing ":" on the end of the complete
23 path, because that's what's done in MacPerl's environment and helps
24 to distinguish a file path from a directory path.
25 IMPORTANT NOTE: Beginning with version 1.3 of this module, the
27 resulting path is relative by default and not absolute. This decision
28 was made due to portability reasons. Since "File::Spec->catdir()"
29 returns relative paths on all other operating systems, it will now
30 also follow this convention on Mac OS. Note that this may break some
31 existing scripts.
32 The intended purpose of this routine is to concatenate directory
34 names. But because of the nature of Macintosh paths, some additional
35 possibilities are allowed to make using this routine give reasonable
36 results for some common situations. In other words, you are also
37 allowed to concatenate paths instead of directory names (strictly
38 speaking, a string like ":a" is a path, but not a name, since it
39 contains a punctuation character ":").
40 So, beside calls like
42 catdir("a") = ":a:"
44 catdir("a","b") = ":a:b:"
45 catdir() = "" (special case)
46 calls like the following
48 catdir(":a:") = ":a:"
50 catdir(":a","b") = ":a:b:"
51 catdir(":a:","b") = ":a:b:"
52 catdir(":a:",":b:") = ":a:b:"
53 catdir(":") = ":"
54 are allowed.
56 Here are the rules that are used in catdir(); note that we try to be
58 as compatible as possible to Unix:
59 1.
61 The resulting path is relative by default, i.e. the resulting path
62 will have a leading colon.
63 2.
65 A trailing colon is added automatically to the resulting path, to
66 denote a directory.
67 3.
69 Generally, each argument has one leading ":" and one trailing ":"
70 removed (if any). They are then joined together by a ":". Special
71 treatment applies for arguments denoting updir paths like "::lib:",
72 see (4), or arguments consisting solely of colons ("colon paths"),
73 see (5).
74 4.
76 When an updir path like ":::lib::" is passed as argument, the
77 number of directories to climb up is handled correctly, not
78 removing leading or trailing colons when necessary. E.g.
79 catdir(":::a","::b","c") = ":::a::b:c:"
81 catdir(":::a::","::b","c") = ":::a:::b:c:"
82 5.
84 Adding a colon ":" or empty string "" to a path at any position
85 doesn't alter the path, i.e. these arguments are ignored. (When a
86 "" is passed as the first argument, it has a special meaning, see
87 (6)). This way, a colon ":" is handled like a "." (curdir) on Unix,
88 while an empty string "" is generally ignored (see "canonpath()" in
89 File::Spec::Unix ). Likewise, a "::" is handled like a ".."
90 (updir), and a ":::" is handled like a "../.." etc. E.g.
91 catdir("a",":",":","b") = ":a:b:"
93 catdir("a",":","::",":b") = ":a::b:"
94 6.
96 If the first argument is an empty string "" or is a volume name,
97 i.e. matches the pattern /^[^:]+:/, the resulting path is absolute.
98 7.
100 Passing an empty string "" as the first argument to catdir() is
101 like passing"File::Spec->rootdir()" as the first argument, i.e.
102 catdir("","a","b") is the same as
104 catdir(rootdir(),"a","b").
106 This is true on Unix, where "catdir("","a","b")" yields "/a/b" and
108 rootdir() is "/". Note that rootdir() on Mac OS is the startup
109 volume, which is the closest in concept to Unix' "/". This should
110 help to run existing scripts originally written for Unix.
111 8.
113 For absolute paths, some cleanup is done, to ensure that the volume
114 name isn't immediately followed by updirs. This is invalid, because
115 this would go beyond "root". Generally, these cases are handled
116 like their Unix counterparts:
117 Unix:
119 Unix->catdir("","") = "/"
120 Unix->catdir("",".") = "/"
121 Unix->catdir("","..") = "/" # can't go
122 # beyond root
123 Unix->catdir("",".","..","..","a") = "/a"
124 Mac:
125 Mac->catdir("","") = rootdir() # (e.g. "HD:")
126 Mac->catdir("",":") = rootdir()
127 Mac->catdir("","::") = rootdir() # can't go
128 # beyond root
129 Mac->catdir("",":","::","::","a") = rootdir() . "a:"
130 # (e.g. "HD:a:")
131 However, this approach is limited to the first arguments following
133 "root" (again, see "canonpath()" in File::Spec::Unix. If there are
134 more arguments that move up the directory tree, an invalid path
135 going beyond root can be created.
136 As you've seen, you can force catdir() to create an absolute path by
138 passing either an empty string or a path that begins with a volume
139 name as the first argument. However, you are strongly encouraged not
140 to do so, since this is done only for backward compatibility. Newer
141 versions of File::Spec come with a method called catpath() (see
142 below), that is designed to offer a portable solution for the
143 creation of absolute paths. It takes volume, directory and file
144 portions and returns an entire path. While catdir() is still suitable
145 for the concatenation of directory names, you are encouraged to use
146 catpath() to concatenate volume names and directory paths. E.g.
147 $dir = File::Spec->catdir("tmp","sources");
149 $abs_path = File::Spec->catpath("MacintoshHD:", $dir,"");
150 yields
152 "MacintoshHD:tmp:sources:" .
154 catfile
156 Concatenate one or more directory names and a filename to form a
157 complete path ending with a filename. Resulting paths are relative by
158 default, but can be forced to be absolute (but avoid this).
159 IMPORTANT NOTE: Beginning with version 1.3 of this module, the
161 resulting path is relative by default and not absolute. This decision
162 was made due to portability reasons. Since "File::Spec->catfile()"
163 returns relative paths on all other operating systems, it will now
164 also follow this convention on Mac OS. Note that this may break some
165 existing scripts.
166 The last argument is always considered to be the file portion. Since
168 catfile() uses catdir() (see above) for the concatenation of the
169 directory portions (if any), the following with regard to relative
170 and absolute paths is true:
171 catfile("") = ""
173 catfile("file") = "file"
174 but
176 catfile("","") = rootdir() # (e.g. "HD:")
178 catfile("","file") = rootdir() . file # (e.g. "HD:file")
179 catfile("HD:","file") = "HD:file"
180 This means that catdir() is called only when there are two or more
182 arguments, as one might expect.
183 Note that the leading ":" is removed from the filename, so that
185 catfile("a","b","file") = ":a:b:file" and
187 catfile("a","b",":file") = ":a:b:file"
189 give the same answer.
191 To concatenate volume names, directory paths and filenames, you are
193 encouraged to use catpath() (see below).
194 curdir
196 Returns a string representing the current directory. On Mac OS, this
197 is ":".
198 devnull
200 Returns a string representing the null device. On Mac OS, this is
201 "Dev:Null".
202 rootdir
204 Returns the empty string. Mac OS has no real root directory.
205 tmpdir
207 Returns the contents of $ENV{TMPDIR}, if that directory exits or the
208 current working directory otherwise. Under MacPerl, $ENV{TMPDIR} will
209 contain a path like "MacintoshHD:Temporary Items:", which is a hidden
210 directory on your startup volume.
211 updir
213 Returns a string representing the parent directory. On Mac OS, this
214 is "::".
215 file_name_is_absolute
217 Takes as argument a path and returns true, if it is an absolute path.
218 If the path has a leading ":", it's a relative path. Otherwise, it's
219 an absolute path, unless the path doesn't contain any colons, i.e.
220 it's a name like "a". In this particular case, the path is considered
221 to be relative (i.e. it is considered to be a filename). Use ":" in
222 the appropriate place in the path if you want to distinguish
223 unambiguously. As a special case, the filename '' is always
224 considered to be absolute. Note that with version 1.2 of
225 File::Spec::Mac, this does no longer consult the local filesystem.
226 E.g.
228 File::Spec->file_name_is_absolute("a"); # false (relative)
230 File::Spec->file_name_is_absolute(":a:b:"); # false (relative)
231 File::Spec->file_name_is_absolute("MacintoshHD:");
232 # true (absolute)
233 File::Spec->file_name_is_absolute(""); # true (absolute)
234 path
236 Returns the null list for the MacPerl application, since the concept
237 is usually meaningless under Mac OS. But if you're using the MacPerl
238 tool under MPW, it gives back $ENV{Commands} suitably split, as is
239 done in :lib:ExtUtils:MM_Mac.pm.
240 splitpath
242 ($volume,$directories,$file) = File::Spec->splitpath( $path );
243 ($volume,$directories,$file) = File::Spec->splitpath( $path,
244 $no_file );
245 Splits a path into volume, directory, and filename portions.
247 On Mac OS, assumes that the last part of the path is a filename
249 unless $no_file is true or a trailing separator ":" is present.
250 The volume portion is always returned with a trailing ":". The
252 directory portion is always returned with a leading (to denote a
253 relative path) and a trailing ":" (to denote a directory). The file
254 portion is always returned without a leading ":". Empty portions are
255 returned as empty string ''.
256 The results can be passed to catpath() to get back a path equivalent
258 to (usually identical to) the original path.
259 splitdir
261 The opposite of catdir().
262 @dirs = File::Spec->splitdir( $directories );
264 $directories should be only the directory portion of the path on
266 systems that have the concept of a volume or that have path syntax
267 that differentiates files from directories. Consider using
268 splitpath() otherwise.
269 Unlike just splitting the directories on the separator, empty
271 directory names ("") can be returned. Since catdir() on Mac OS always
272 appends a trailing colon to distinguish a directory path from a file
273 path, a single trailing colon will be ignored, i.e. there's no empty
274 directory name after it.
275 Hence, on Mac OS, both
277 File::Spec->splitdir( ":a:b::c:" ); and
279 File::Spec->splitdir( ":a:b::c" );
280 yield:
282 ( "a", "b", "::", "c")
284 while
286 File::Spec->splitdir( ":a:b::c::" );
288 yields:
290 ( "a", "b", "::", "c", "::")
292 catpath
294 $path = File::Spec->catpath($volume,$directory,$file);
295 Takes volume, directory and file portions and returns an entire path.
297 On Mac OS, $volume, $directory and $file are concatenated. A ':' is
298 inserted if need be. You may pass an empty string for each portion.
299 If all portions are empty, the empty string is returned. If $volume
300 is empty, the result will be a relative path, beginning with a ':'.
301 If $volume and $directory are empty, a leading ":" (if any) is
302 removed form $file and the remainder is returned. If $file is empty,
303 the resulting path will have a trailing ':'.
304 abs2rel
306 Takes a destination path and an optional base path and returns a
307 relative path from the base path to the destination path:
308 $rel_path = File::Spec->abs2rel( $path ) ;
310 $rel_path = File::Spec->abs2rel( $path, $base ) ;
311 Note that both paths are assumed to have a notation that
313 distinguishes a directory path (with trailing ':') from a file path
314 (without trailing ':').
315 If $base is not present or '', then the current working directory is
317 used. If $base is relative, then it is converted to absolute form
318 using rel2abs(). This means that it is taken to be relative to the
319 current working directory.
320 If $path and $base appear to be on two different volumes, we will not
322 attempt to resolve the two paths, and we will instead simply return
323 $path. Note that previous versions of this module ignored the volume
324 of $base, which resulted in garbage results part of the time.
325 If $base doesn't have a trailing colon, the last element of $base is
327 assumed to be a filename. This filename is ignored. Otherwise all
328 path components are assumed to be directories.
329 If $path is relative, it is converted to absolute form using
331 rel2abs(). This means that it is taken to be relative to the current
332 working directory.
333 Based on code written by Shigio Yamaguchi.
335 rel2abs
337 Converts a relative path to an absolute path:
338 $abs_path = File::Spec->rel2abs( $path ) ;
340 $abs_path = File::Spec->rel2abs( $path, $base ) ;
341 Note that both paths are assumed to have a notation that
343 distinguishes a directory path (with trailing ':') from a file path
344 (without trailing ':').
345 If $base is not present or '', then $base is set to the current
347 working directory. If $base is relative, then it is converted to
348 absolute form using rel2abs(). This means that it is taken to be
349 relative to the current working directory.
350 If $base doesn't have a trailing colon, the last element of $base is
352 assumed to be a filename. This filename is ignored. Otherwise all
353 path components are assumed to be directories.
354 If $path is already absolute, it is returned and $base is ignored.
356 Based on code written by Shigio Yamaguchi.
358
360 See the authors list in File::Spec. Mac OS support by Paul Schinder
361 <schinder@pobox.com> and Thomas Wegner <wegner_thomas@yahoo.com>.
362
364 Copyright (c) 2004 by the Perl 5 Porters. All rights reserved.
365 This program is free software; you can redistribute it and/or modify it
367 under the same terms as Perl itself.
368
370 See File::Spec and File::Spec::Unix. This package overrides the
371 implementation of these methods, not the semantics.
372perl v5.36.0 2023-01-20 File::Spec::Mac(3)