GLOB
Section: Linux Programmer's Manual (3)
Updated: 11 May 1998
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,
which is a
glob_t
which is declared in
<glob.h>
and includes the following elements defined by POSIX.2 (more may be
present as a GNU extension):
typedef struct
{
int gl_pathc; /* Count of paths matched so far */
char **gl_pathv; /* List of matched pathnames. */
int gl_offs; /* Slots to reserve in `gl_pathv'. */
} glob_t;
Results are stored in dynamically allocated storage.
The parameter
flags
is made up of bitwise OR of zero or more the following symbolic
constants, which modify the of behaviour of
glob():
- GLOB_ERR
-
which means to return upon read error (because a directory does not
have read permission, for example),
- GLOB_MARK
-
which means to append a slash to each path which corresponds to a directory,
- GLOB_NOSORT
-
which means don't sort the returned pathnames (they are by default),
- GLOB_DOOFS
-
which means that
pglob->gl_offs
slots will be reserved at the beginning of the list of strings in
pglob->pathv,
- GLOB_NOCHECK
-
which means that, if no pattern matches, to return the original pattern,
- GLOB_APPEND
-
which means to append to the results of a previous call. Do not set
this flag on the first invocation of
glob().
- GLOB_NOESCAPE
-
which means that meta characters cannot be quoted by backslashes.
The flags may also include some of the following, which are GNU
extensions and not defined by POSIX.2:
- GLOB_PERIOD
-
which means that a leading period can be matched by meta characters,
- GLOB_ALTDIRFUNC
-
which means that alternative functions
pglob->gl_closedir,
pglob->gl_readdir,
pglob->gl_opendir,
pglob->gl_lstat, and
pglob->gl_stat
are used for file system access instead of the normal library
functions,
- GLOB_BRACE
-
which means that
csh(1)
style brace expresions {a,b} are expanded,
- GLOB_NOMAGIC
-
which means that the pattern is returned if it contains no metacharacters,
- GLOB_TILDE
-
which means that tilde expansion is carried out, and
- GLOB_ONLYDIR
-
which means that only directories are matched.
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(), readdir(), or stat().
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
a pointer to the list of matched pathnames. The first pointer after
the last pathname is
NULL.
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 VALUES
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.
EXAMPLES
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_DOOFS, NULL, &globbuf);
glob("../*.c", GLOB_DOOFS | GLOB_APPEND, NULL, &globbuf);
globbuf.gl_pathv[0] = "ls";
globbuf.gl_pathv[1] = "-l";
execvp("ls", &globbuf.gl_pathv[0]);
CONFORMING TO
POSIX.2
BUGS
The
glob()
function may fail due to failure of underlying function calls, such as
malloc() or opendir().
These will store their error code in
errno.
The structure elements
gl_pathc
and
gl_offs
should be declared as
size_t,
according to POSIX.2, but are declared as
int.
SEE ALSO
ls(1),
sh(1),
stat(2),
exec(3),
malloc(3),
opendir(3),
readdir(3),
wordexp(3),
glob(7)