xref: /freebsd/lib/libc/gen/glob.3 (revision afe61c15161c324a7af299a9b8457aba5afc92db)
1.\" Copyright (c) 1989, 1991, 1993, 1994
2.\"	The Regents of the University of California.  All rights reserved.
3.\"
4.\" This code is derived from software contributed to Berkeley by
5.\" Guido van Rossum.
6.\" Redistribution and use in source and binary forms, with or without
7.\" modification, are permitted provided that the following conditions
8.\" are met:
9.\" 1. Redistributions of source code must retain the above copyright
10.\"    notice, this list of conditions and the following disclaimer.
11.\" 2. Redistributions in binary form must reproduce the above copyright
12.\"    notice, this list of conditions and the following disclaimer in the
13.\"    documentation and/or other materials provided with the distribution.
14.\" 3. All advertising materials mentioning features or use of this software
15.\"    must display the following acknowledgement:
16.\"	This product includes software developed by the University of
17.\"	California, Berkeley and its contributors.
18.\" 4. Neither the name of the University nor the names of its contributors
19.\"    may be used to endorse or promote products derived from this software
20.\"    without specific prior written permission.
21.\"
22.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32.\" SUCH DAMAGE.
33.\"
34.\"     @(#)glob.3	8.3 (Berkeley) 4/16/94
35.\"
36.Dd April 16, 1994
37.Dt GLOB 3
38.Os
39.Sh NAME
40.Nm glob ,
41.Nm globfree
42.Nd generate pathnames matching a pattern
43.Sh SYNOPSIS
44.Fd #include <glob.h>
45.Ft int
46.Fn glob "const char *pattern" "int flags" "const int (*errfunc)(const char *, int)" "glob_t *pglob"
47.Ft void
48.Fn globfree "glob_t *pglob"
49.Sh DESCRIPTION
50The
51.Fn glob
52function
53is a pathname generator that implements the rules for file name pattern
54matching used by the shell.
55.Pp
56The include file
57.Pa glob.h
58defines the structure type
59.Fa glob_t ,
60which contains at least the following fields:
61.Bd -literal
62typedef struct {
63	int gl_pathc;		/* count of total paths so far */
64	int gl_matchc;		/* count of paths matching pattern */
65	int gl_offs;		/* reserved at beginning of gl_pathv */
66	int gl_flags;		/* returned flags */
67	char **gl_pathv;	/* list of paths matching pattern */
68} glob_t;
69.Ed
70.Pp
71The argument
72.Fa pattern
73is a pointer to a pathname pattern to be expanded.
74The
75.Fn glob
76argument
77matches all accessible pathnames against the pattern and creates
78a list of the pathnames that match.
79In order to have access to a pathname,
80.Fn glob
81requires search permission on every component of a path except the last
82and read permission on each directory of any filename component of
83.Fa pattern
84that contains any of the special characters
85.Ql * ,
86.Ql ?
87or
88.Ql [ .
89.Pp
90The
91.Fn glob
92argument
93stores the number of matched pathnames into the
94.Fa gl_pathc
95field, and a pointer to a list of pointers to pathnames into the
96.Fa gl_pathv
97field.
98The first pointer after the last pathname is
99.Dv NULL .
100If the pattern does not match any pathnames, the returned number of
101matched paths is set to zero.
102.Pp
103It is the caller's responsibility to create the structure pointed to by
104.Fa pglob .
105The
106.Fn glob
107function allocates other space as needed, including the memory pointed
108to by
109.Fa gl_pathv .
110.Pp
111The argument
112.Fa flags
113is used to modify the behavior of
114.Fn glob .
115The value of
116.Fa flags
117is the bitwise inclusive
118.Tn OR
119of any of the following
120values defined in
121.Pa glob.h :
122.Bl -tag -width GLOB_ALTDIRFUNC
123.It Dv GLOB_APPEND
124Append pathnames generated to the ones from a previous call (or calls)
125to
126.Fn glob .
127The value of
128.Fa gl_pathc
129will be the total matches found by this call and the previous call(s).
130The pathnames are appended to, not merged with the pathnames returned by
131the previous call(s).
132Between calls, the caller must not change the setting of the
133.Dv GLOB_DOOFFS
134flag, nor change the value of
135.Fa gl_offs
136when
137.Dv GLOB_DOOFFS
138is set, nor (obviously) call
139.Fn globfree
140for
141.Fa pglob .
142.It Dv GLOB_DOOFFS
143Make use of the
144.Fa gl_offs
145field.
146If this flag is set,
147.Fa gl_offs
148is used to specify how many
149.Dv NULL
150pointers to prepend to the beginning
151of the
152.Fa gl_pathv
153field.
154In other words,
155.Fa gl_pathv
156will point to
157.Fa gl_offs
158.Dv NULL
159pointers,
160followed by
161.Fa gl_pathc
162pathname pointers, followed by a
163.Dv NULL
164pointer.
165.It Dv GLOB_ERR
166Causes
167.Fn glob
168to return when it encounters a directory that it cannot open or read.
169Ordinarily,
170.Fn glob
171continues to find matches.
172.It Dv GLOB_MARK
173Each pathname that is a directory that matches
174.Fa pattern
175has a slash
176appended.
177.It Dv GLOB_NOCHECK
178If
179.Fa pattern
180does not match any pathname, then
181.Fn glob
182returns a list
183consisting of only
184.Fa pattern ,
185with the number of total pathnames is set to 1, and the number of matched
186pathnames set to 0.
187If
188.Dv GLOB_QUOTE
189is set, its effect is present in the pattern returned.
190.It Dv GLOB_NOSORT
191By default, the pathnames are sorted in ascending
192.Tn ASCII
193order;
194this flag prevents that sorting (speeding up
195.Fn glob ) .
196.El
197.Pp
198The following values may also be included in
199.Fa flags ,
200however, they are non-standard extensions to
201.St -p1003.2 .
202.Bl -tag -width GLOB_ALTDIRFUNC
203.It Dv GLOB_ALTDIRFUNC
204The following additional fields in the pglob structure have been
205initialized with alternate functions for glob to use to open, read,
206and close directories and to get stat information on names found
207in those directories.
208.Bd -literal
209void *(*gl_opendir)(const char * name);
210struct dirent *(*gl_readdir)(void *);
211void (*gl_closedir)(void *);
212int (*gl_lstat)(const char *name, struct stat *st);
213int (*gl_stat)(const char *name, struct stat *st);
214.Ed
215.Pp
216This extension is provided to allow programs such as
217.Xr restore 8
218to provide globbing from directories stored on tape.
219.It Dv GLOB_BRACE
220Pre-process the pattern string to expand
221.Ql {pat,pat,...}
222strings like
223.Xr csh 1. The pattern
224.Ql {}
225is left unexpanded for historical reasons
226.Xr (Csh 1
227does the same thing to
228ease typing
229of
230.Xr find 1
231patterns).
232.It Dv GLOB_MAGCHAR
233Set by the
234.Fn glob
235function if the pattern included globbing characters.
236See the description of the usage of the
237.Fa gl_matchc
238structure member for more details.
239.It Dv GLOB_NOMAGIC
240Is the same as
241.Dv GLOB_NOCHECK
242but it only appends the
243.Fa pattern
244if it does not contain any of the special characters ``*'', ``?'' or ``[''.
245.Dv GLOB_NOMAGIC
246is provided to simplify implementing the historic
247.Xr csh 1
248globbing behavior and should probably not be used anywhere else.
249.It Dv GLOB_QUOTE
250Use the backslash
251.Pq Ql \e
252character for quoting: every occurrence of
253a backslash followed by a character in the pattern is replaced by that
254character, avoiding any special interpretation of the character.
255.It Dv GLOB_TILDE
256Expand patterns that start with
257.Ql ~
258to user name home directories.
259.El
260.Pp
261If, during the search, a directory is encountered that cannot be opened
262or read and
263.Fa errfunc
264is
265.Pf non- Dv NULL ,
266.Fn glob
267calls
268.Fa (*errfunc)(path, errno) .
269This may be unintuitive: a pattern like
270.Ql */Makefile
271will try to
272.Xr stat 2
273.Ql foo/Makefile
274even if
275.Ql foo
276is not a directory, resulting in a
277call to
278.Fa errfunc .
279The error routine can suppress this action by testing for
280.Dv ENOENT
281and
282.Dv ENOTDIR ;
283however, the
284.Dv GLOB_ERR
285flag will still cause an immediate
286return when this happens.
287.Pp
288If
289.Fa errfunc
290returns non-zero,
291.Fn glob
292stops the scan and returns
293.Dv GLOB_ABEND
294after setting
295.Fa gl_pathc
296and
297.Fa gl_pathv
298to reflect any paths already matched.
299This also happens if an error is encountered and
300.Dv GLOB_ERR
301is set in
302.Fa flags ,
303regardless of the return value of
304.Fa errfunc ,
305if called.
306If
307.Dv GLOB_ERR
308is not set and either
309.Fa errfunc
310is
311.Dv NULL
312or
313.Fa errfunc
314returns zero, the error is ignored.
315.Pp
316The
317.Fn globfree
318function frees any space associated with
319.Fa pglob
320from a previous call(s) to
321.Fn glob .
322.Sh RETURN VALUES
323On successful completion,
324.Fn glob
325returns zero.
326In addition the fields of
327.Fa pglob
328contain the values described below:
329.Bl -tag -width GLOB_NOCHECK
330.It Fa gl_pathc
331contains the total number of matched pathnames so far.
332This includes other matches from previous invocations of
333.Fn glob
334if
335.Dv GLOB_APPEND
336was specified.
337.It Fa gl_matchc
338contains the number of matched pathnames in the current invocation of
339.Fn glob .
340.It Fa gl_flags
341contains a copy of the
342.Fa flags
343parameter with the bit
344.Dv GLOB_MAGCHAR
345set if
346.Fa pattern
347contained any of the special characters ``*'', ``?'' or ``['', cleared
348if not.
349.It Fa gl_pathv
350contains a pointer to a
351.Dv NULL Ns -terminated
352list of matched pathnames.
353However, if
354.Fa gl_pathc
355is zero, the contents of
356.Fa gl_pathv
357are undefined.
358.El
359.Pp
360If
361.Fn glob
362terminates due to an error, it sets errno and returns one of the
363following non-zero constants, which are defined in the include
364file
365.Aq Pa glob.h :
366.Bl -tag -width GLOB_NOCHECK
367.It Dv GLOB_NOSPACE
368An attempt to allocate memory failed.
369.It Dv GLOB_ABEND
370The scan was stopped because an error was encountered and either
371.Dv GLOB_ERR
372was set or
373.Fa (*errfunc)()
374returned non-zero.
375.El
376.Pp
377The arguments
378.Fa pglob\->gl_pathc
379and
380.Fa pglob\->gl_pathv
381are still set as specified above.
382.Sh EXAMPLE
383A rough equivalent of
384.Ql "ls -l *.c *.h"
385can be obtained with the
386following code:
387.Bd -literal -offset indent
388glob_t g;
389
390g.gl_offs = 2;
391glob("*.c", GLOB_DOOFFS, NULL, &g);
392glob("*.h", GLOB_DOOFFS | GLOB_APPEND, NULL, &g);
393g.gl_pathv[0] = "ls";
394g.gl_pathv[1] = "-l";
395execvp("ls", g.gl_pathv);
396.Ed
397.Sh SEE ALSO
398.Xr sh 1 ,
399.Xr fnmatch 3 ,
400.Xr regexp 3
401.Sh STANDARDS
402The
403.Fn glob
404function is expected to be
405.St -p1003.2
406compatible with the exception
407that the flags
408.Dv GLOB_ALTDIRFUNC,
409.Dv GLOB_BRACE
410.Dv GLOB_MAGCHAR,
411.Dv GLOB_NOMAGIC,
412.Dv GLOB_QUOTE,
413and
414.Dv GLOB_TILDE,
415and the fields
416.Fa gl_matchc
417and
418.Fa gl_flags
419should not be used by applications striving for strict
420.Tn POSIX
421conformance.
422.Sh HISTORY
423The
424.Fn glob
425and
426.Fn globfree
427functions first appeared in 4.4BSD.
428.Sh BUGS
429Patterns longer than
430.Dv MAXPATHLEN
431may cause unchecked errors.
432.Pp
433The
434.Fn glob
435argument
436may fail and set errno for any of the errors specified for the
437library routines
438.Xr stat 2 ,
439.Xr closedir 3 ,
440.Xr opendir 3 ,
441.Xr readdir 3 ,
442.Xr malloc 3 ,
443and
444.Xr free 3 .
445