GLOB
Section: Linux Programmer's Manual (3)
Updated: 2007-10-10
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NAME
glob, globfree - find pathnames matching a pattern, free memory from glob()
SYNOPSIS
#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);
DESCRIPTION
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 file system 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 non-directory 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 non-zero, 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.
RETURN VALUE
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.
CONFORMING TO
POSIX.2, POSIX.1-2001.
NOTES
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 libc4, libc5 and glibc 2.0.
BUGS
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.
EXAMPLE
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]);
SEE ALSO
ls(1),
sh(1),
stat(2),
exec(3),
fnmatch(3),
malloc(3),
opendir(3),
readdir(3),
wordexp(3),
glob(7)
COLOPHON
This page is part of release 3.22 of the Linux
man-pages
project.
A description of the project,
and information about reporting bugs,
can be found at
http://www.kernel.org/doc/man-pages/.