GLOB(3) manual page
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glob, globfree - find pathnames matching
a pattern, free memory from glob()
#include <glob.h>
int glob(const char *pattern, int flags,
int (*errfunc) (const char *epath, int eerrno),
glob_t *pglob);
void globfree(glob_t *pglob);
The glob() function searches for
all the pathnames matching pattern according to the rules used by the shell
(see glob(7)
). No tilde expansion or parameter substitution is done; if
you want these, use wordexp(3)
.
The globfree() function frees the dynamically
allocated storage from an earlier call to glob().
The results of a glob()
call are stored in the structure pointed to by pglob. This structure is
of type glob_t (declared in <glob.h>) and includes the following elements
defined by POSIX.2 (more may be present as an extension):
typedef struct {
size_t gl_pathc; /* Count of paths matched so far */
char **gl_pathv; /* List of matched pathnames. */
size_t gl_offs; /* Slots to reserve in gl_pathv. */
} glob_t;
Results are stored in dynamically allocated storage.
The argument flags
is made up of the bitwise OR of zero or more the following symbolic constants,
which modify the behavior of glob():
- GLOB_ERR
- Return upon a read error
(because a directory does not have read permission, for example). By default,
glob() attempts carry on despite errors, reading all of the directories
that it can.
- GLOB_MARK
- Append a slash to each path which corresponds to
a directory.
- GLOB_NOSORT
- Don’t sort the returned pathnames. The only reason
to do this is to save processing time. By default, the returned pathnames
are sorted.
- GLOB_DOOFFS
- Reserve pglob->gl_offs slots at the beginning of the
list of strings in pglob->pathv. The reserved slots contain null pointers.
- GLOB_NOCHECK
- If no pattern matches, return the original pattern. By default,
glob() returns GLOB_NOMATCH if there are no matches.
- GLOB_APPEND
- Append
the results of this call to the vector of results returned by a previous
call to glob(). Do not set this flag on the first invocation of glob().
- GLOB_NOESCAPE
- Don’t allow backslash (aq\aq) to be used as an escape character. Normally,
a backslash can be used to quote the following character, providing a mechanism
to turn off the special meaning metacharacters.
flags may also include any
of the following, which are GNU extensions and not defined by POSIX.2:
- GLOB_PERIOD
- Allow a leading period to be matched by metacharacters. By default, metacharacters
can’t match a leading period.
- GLOB_ALTDIRFUNC
- Use alternative functions pglob->gl_closedir,
pglob->gl_readdir, pglob->gl_opendir, pglob->gl_lstat, and pglob->gl_stat for filesystem
access instead of the normal library functions.
- GLOB_BRACE
- Expand csh(1)
style brace expressions of the form {a,b}. Brace expressions can be nested.
Thus, for example, specifying the pattern "{foo/{,cat,dog},bar}" would
return the same results as four separate glob() calls using the strings:
"foo/", "foo/cat", "foo/dog", and "bar".
- GLOB_NOMAGIC
- If the pattern contains
no metacharacters, then it should be returned as the sole matching word,
even if there is no file with that name.
- GLOB_TILDE
- Carry out tilde expansion.
If a tilde (aq~aq) is the only character in the pattern, or an initial
tilde is followed immediately by a slash (aq/aq), then the home directory
of the caller is substituted for the tilde. If an initial tilde is followed
by a username (e.g., "~andrea/bin"), then the tilde and username are substituted
by the home directory of that user. If the username is invalid, or the home
directory cannot be determined, then no substitution is performed.
- GLOB_TILDE_CHECK
- This provides behavior similar to that of GLOB_TILDE. The difference is
that if the username is invalid, or the home directory cannot be determined,
then instead of using the pattern itself as the name, glob() returns GLOB_NOMATCH
to indicate an error.
- GLOB_ONLYDIR
- This is a hint to glob() that the caller
is interested only in directories that match the pattern. If the implementation
can easily determine file-type information, then nondirectory files are
not returned to the caller. However, the caller must still check that returned
files are directories. (The purpose of this flag is merely to optimize performance
when the caller is interested only in directories.)
If errfunc is not NULL,
it will be called in case of an error with the arguments epath, a pointer
to the path which failed, and eerrno, the value of errno as returned from
one of the calls to opendir(3)
, readdir(3)
, or stat(2)
. If errfunc returns
nonzero, or if GLOB_ERR is set, glob() will terminate after the call to
errfunc.
Upon successful return, pglob->gl_pathc contains the number of matched
pathnames and pglob->gl_pathv contains a pointer to the list of pointers
to matched pathnames. The list of pointers is terminated by a null pointer.
It is possible to call glob() several times. In that case, the GLOB_APPEND
flag has to be set in flags on the second and later invocations.
As a GNU
extension, pglob->gl_flags is set to the flags specified, ored with GLOB_MAGCHAR
if any metacharacters were found.
On successful completion,
glob() returns zero. Other possible returns are:
- GLOB_NOSPACE
- for running
out of memory,
- GLOB_ABORTED
- for a read error, and
- GLOB_NOMATCH
- for no found
matches.
POSIX.2, POSIX.1-2001.
The structure elements gl_pathc
and gl_offs are declared as size_t in glibc 2.1, as they should be according
to POSIX.2, but are declared as int in glibc 2.0.
The glob() function
may fail due to failure of underlying function calls, such as malloc(3)
or opendir(3)
. These will store their error code in errno.
One example
of use is the following code, which simulates typing
ls -l *.c ../*.c
in the
shell:
glob_t globbuf;
globbuf.gl_offs = 2;
glob("*.c", GLOB_DOOFFS, NULL, &globbuf);
glob("../*.c", GLOB_DOOFFS | GLOB_APPEND, NULL, &globbuf);
globbuf.gl_pathv[0] = "ls";
globbuf.gl_pathv[1] = "-l";
execvp("ls", &globbuf.gl_pathv[0]);
ls(1)
, sh(1)
, stat(2)
, exec(3)
, fnmatch(3)
, malloc(3)
, opendir(3)
,
readdir(3)
, wordexp(3)
, glob(7)
This page is part of release 3.78
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