GLOB
Section: C Library Functions (3)
Updated: March 19, 1991
Index
Return to Main Contents
NAME
glob, globfree - generate pathnames matching a pattern
SYNOPSIS
#include <glob.h>
glob(const char *pattern, int flags,
const int (*errfunc)(char *, int), glob_t *pglob);
void globfree(glob_t *pglob);
DESCRIPTION
Glob
is a pathname generator that implements the rules for file name pattern
matching used by the shell.
The include file
glob.h
defines the structure type
glob_t,
which contains at least the following fields:
-
typedef struct {
int gl_pathc; /* count of total paths so far */
int gl_matchc; /* count of paths matching pattern */
int gl_offs; /* reserved at beginning of gl_pathv */
int gl_flags; /* returned flags */
char **gl_pathv; /* list of paths matching pattern */
} glob_t;
The argument
pattern
is a pointer to a pathname pattern to be expanded.
Glob
matches all accessible pathnames against the pattern and creates
a list of the pathnames that match.
In order to have access to a pathname,
glob
requires search permission on every component of a path except the last
and read permission on each directory of any filename component of
pattern
that contains any of the special characters ``*'', ``?'' or ``[''.
Glob
stores the number of matched pathnames into the
gl_pathc
field, and a pointer to a list of pointers to pathnames into the
gl_pathv
field.
The first pointer after the last pathname is NULL.
If the pattern does not match any pathnames, the returned number of
matched paths is set to zero.
It is the caller's responsibility to create the structure pointed to by
pglob.
The
glob
function allocates other space as needed, including the memory pointed
to by
gl_pathv.
The argument
flags
is used to modify the behavior of
glob.
The value of
flags
is the bitwise inclusive OR of any of the following
values defined in
glob.h:
- GLOB_APPEND
-
Append pathnames generated to the ones from a previous call (or calls)
to
glob.
The value of
gl_pathc
will be the total matches found by this call and the previous call(s).
The pathnames are appended to, not merged with the pathnames returned by
the previous call(s).
Between calls, the caller must not change the setting of the
GLOB_DOOFFS flag, nor change the value of
gl_offs
when
GLOB_DOOFFS is set, nor (obviously) call
globfree
for
pglob.
- GLOB_DOOFFS
-
Make use of the
gl_offs
field.
If this flag is set,
gl_offs
is used to specify how many NULL pointers to prepend to the beginning
of the
gl_pathv
field.
In other words,
gl_pathv
will point to
gl_offs
NULL pointers,
followed by
gl_pathc
pathname pointers, followed by a NULL pointer.
- GLOB_ERR
-
Causes
glob
to return when it encounters a directory that it cannot open or read.
Ordinarily,
glob
continues to find matches.
- GLOB_MARK
-
Each pathname that is a directory that matches
pattern
has a slash
appended.
- GLOB_NOSORT
-
By default, the pathnames are sorted in ascending ASCII order;
this flag prevents that sorting (speeding up
glob).
- GLOB_NOCHECK
-
If
pattern
does not match any pathname, then
glob
returns a list
consisting of only
pattern,
with the number of total pathnames is set to 1, and the number of matched
pathnames set to 0.
If
GLOB_QUOTE
is set, its effect is present in the pattern returned.
- GLOB_QUOTE
-
Use the backslash (``\'') character for quoting: every occurrence of
a backslash followed by a character in the pattern is replaced by that
character, avoiding any special interpretation of the character.
- GLOB_NOMAGIC
-
Is the same as GLOB_NOCHECK but it only appends the
pattern
if it does not contain any of the special characters ``*'', ``?'' or ``[''.
GLOB_NOMAGIC is used to simplify implementing the globbing behavior in
csh(1).
If, during the search, a directory is encountered that cannot be opened
or read and
errfunc
is non-NULL,
glob
calls (*errfunc)(path, errno).
This may be unintuitive: a pattern like ``*/Makefile'' will try to
stat(2)
``foo/Makefile'' even if ``foo'' is not a directory, resulting in a
call to
errfunc.
The error routine can suppress this action by testing for ENOENT and
ENOTDIR; however, the GLOB_ERR flag will still cause an immediate
return when this happens.
If
errfunc
returns non-zero,
glob
stops the scan and returns
GLOB_ABEND
after setting
gl_pathc
and
gl_pathv
to reflect any paths already matched.
This also happens if an error is encountered and
GLOB_ERR
is set in
flags,
regardless of the return value of
errfunc,
if called.
If
GLOB_ERR
is not set and either
errfunc
is NULL or
errfunc
returns zero, the error is ignored.
The
globfree
function frees any space associated with
pglob
from a previous call(s) to
glob.
RETURNS
On successful completion,
glob
returns zero.
In addition the fields of
pglob
contain the values described below:
- gl_pathc
-
contains the total number of matched pathnames so far.
This includes other matches from previous invocations of
glob
if
GLOB_APPEND
was specified.
- gl_matchc
-
contains the number of matched pathnames in the current invocation of
glob.
- gl_flags
-
contains a copy of the
flags
parameter with the bit GLOB_MAGCHAR set if
pattern
contained any of the special characters ``*'', ``?'' or ``['', cleared
if not.
- gl_pathv
-
contains a pointer to a NULL-terminated list of matched pathnames.
However, if
gl_pathc
is zero, the contents of
gl_pathv
are undefined.
If
glob
terminates due to an error, it sets errno and returns one of the
following non-zero constants, which are defined in the include
file <glob.h>:
- GLOB_NOSPACE
-
An attempt to allocate memory failed.
- GLOB_ABEND
-
The scan was stopped because an error was encountered and either
GLOB_ERR was set or (*errfunc)() returned non-zero.
The arguments
pglob->gl_pathc
and
pglob->gl_pathv
are still set as specified above.
STANDARDS
The
glob
function is expected to be POSIX 1003.2 compatible with the exception
that the flag
GLOB_QUOTE
and the fields
gl_matchc
and
gl_flags
should not be used by applications striving for strict POSIX conformance.
EXAMPLE
A rough equivalent of ``ls -l *.c *.h'' can be obtained with the
following code:
- glob_t g;
g.gl_offs = 2;
glob("*.c", GLOB_DOOFFS, NULL, &g);
glob("*.h", GLOB_DOOFFS | GLOB_APPEND, NULL, &g);
g.gl_pathv[0] = "ls";
g.gl_pathv[1] = "-l";
execvp("ls", g.gl_pathv);
SEE ALSO
sh(1), fnmatch(3), wordexp(3), regexp(3)
BUGS
Patterns longer than MAXPATHLEN may cause unchecked errors.
Glob
may fail and set errno for any of the errors specified for the
library routines
stat (2),
closedir (3),
opendir (3),
readdir (3),
malloc (3),
and
free (3).
Index
- NAME
-
- SYNOPSIS
-
- DESCRIPTION
-
- RETURNS
-
- STANDARDS
-
- EXAMPLE
-
- SEE ALSO
-
- BUGS
-
This document was created by
man2html,
using the manual pages.
Time: 23:42:50 GMT, December 11, 2024