On Apache/1.3.41 (Unix) PHP/5.2.5 mod_perl/1.30 mod_gzip/1.3.26.1a
Under GNU General Public License
2008-12-02 08:07 @38.103.63.58 CrawledBy CCBot/1.0 (+http://www.commoncrawl.org/bot.html)
GLOB(P) GLOB(P)
NAME
glob, globfree - generate pathnames matching a pattern
SYNOPSIS
#include <glob.h>
int glob(const char *restrict pattern, int flags,
int(*errfunc)(const char *epath, int eerrno),
glob_t *restrict pglob);
void globfree(glob_t *pglob);
DESCRIPTION
The glob() function is a pathname generator that shall implement the rules defined
in the Shell and Utilities volume of IEEE Std 1003.1-2001, Section 2.13, Pattern
Matching Notation, with optional support for rule 3 in the Shell and Utilities vol-
ume of IEEE Std 1003.1-2001, Section 2.13.3, Patterns Used for Filename Expansion.
The structure type glob_t is defined in <glob.h> and includes at least the follow-
ing members:
Member Type Member Name Description
size_t gl_pathc Count of paths matched by pattern.
char ** gl_pathv Pointer to a list of matched pathnames.
size_t gl_offs Slots to reserve at the beginning of gl_pathv.
The argument pattern is a pointer to a pathname pattern to be expanded. The glob()
function shall match all accessible pathnames against this pattern and develop a
list of all 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 following special characters: â€â€™*â€â€™ , â€â€™?â€â€™ , and â€â€™[â€â€™ .
The glob() function shall store the number of matched pathnames into
pglob->gl_pathc and a pointer to a list of pointers to pathnames into
pglob->gl_pathv. The pathnames shall be in sort order as defined by the current
setting of the LC_COLLATE category; see the Base Definitions volume of
IEEE Std 1003.1-2001, Section 7.3.2, LC_COLLATE. The first pointer after the last
pathname shall be a null pointer. If the pattern does not match any pathnames, the
returned number of matched paths is set to 0, and the contents of pglob->gl_pathv
are implementation-defined.
It is the caller’s responsibility to create the structure pointed to by pglob. The
glob() function shall allocate other space as needed, including the memory pointed
to by gl_pathv. The globfree() function shall free any space associated with pglob
from a previous call to glob().
The flags argument is used to control the behavior of glob(). The value of flags
is a bitwise-inclusive OR of zero or more of the following constants, which are
defined in <glob.h>:
GLOB_APPEND
Append pathnames generated to the ones from a previous call to glob().
GLOB_DOOFFS
Make use of pglob->gl_offs. If this flag is set, pglob->gl_offs is used to
specify how many null pointers to add to the beginning of pglob->gl_pathv.
In other words, pglob->gl_pathv shall point to pglob->gl_offs null pointers,
followed by pglob->gl_pathc pathname pointers, followed by a null pointer.
GLOB_ERR
Cause 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 shall have a slash
appended.
GLOB_NOCHECK
Supports rule 3 in the Shell and Utilities volume of IEEE Std 1003.1-2001,
Section 2.13.3, Patterns Used for Filename Expansion. If pattern does not
match any pathname, then glob() shall return a list consisting of only pat-
tern, and the number of matched pathnames is 1.
GLOB_NOESCAPE
Disable backslash escaping.
GLOB_NOSORT
Ordinarily, glob() sorts the matching pathnames according to the current
setting of the LC_COLLATE category; see the Base Definitions volume of
IEEE Std 1003.1-2001, Section 7.3.2, LC_COLLATE. When this flag is used, the
order of pathnames returned is unspecified.
The GLOB_APPEND flag can be used to append a new set of pathnames to those found in
a previous call to glob(). The following rules apply to applications when two or
more calls to glob() are made with the same value of pglob and without intervening
calls to globfree():
1. The first such call shall not set GLOB_APPEND. All subsequent calls shall set
it.
2. All the calls shall set GLOB_DOOFFS, or all shall not set it.
3. After the second call, pglob->gl_pathv points to a list containing the follow-
ing:
a. Zero or more null pointers, as specified by GLOB_DOOFFS and pglob->gl_offs.
b. Pointers to the pathnames that were in the pglob->gl_pathv list before the
call, in the same order as before.
c. Pointers to the new pathnames generated by the second call, in the speci-
fied order.
4. The count returned in pglob->gl_pathc shall be the total number of pathnames
from the two calls.
5. The application can change any of the fields after a call to glob(). If it
does, the application shall reset them to the original value before a subse-
quent call, using the same pglob value, to globfree() or glob() with the
GLOB_APPEND flag.
If, during the search, a directory is encountered that cannot be opened or read and
errfunc is not a null pointer, glob() calls (*errfunc()) with two arguments:
1. The epath argument is a pointer to the path that failed.
2. The eerrno argument is the value of errno from the failure, as set by
opendir(), readdir(), or stat(). (Other values may be used to report other
errors not explicitly documented for those functions.)
If (*errfunc()) is called and returns non-zero, or if the GLOB_ERR flag is set in
flags, glob() shall stop the scan and return GLOB_ABORTED after setting gl_pathc
and gl_pathv in pglob to reflect the paths already scanned. If GLOB_ERR is not set
and either errfunc is a null pointer or (*errfunc()) returns 0, the error shall be
ignored.
The glob() function shall not fail because of large files.
RETURN VALUE
Upon successful completion, glob() shall return 0. The argument pglob->gl_pathc
shall return the number of matched pathnames and the argument pglob->gl_pathv shall
contain a pointer to a null-terminated list of matched and sorted pathnames. How-
ever, if pglob->gl_pathc is 0, the content of pglob->gl_pathv is undefined.
The globfree() function shall not return a value.
If glob() terminates due to an error, it shall return one of the non-zero constants
defined in <glob.h>. The arguments pglob->gl_pathc and pglob->gl_pathv are still
set as defined above.
ERRORS
The glob() function shall fail and return the corresponding value if:
GLOB_ABORTED
The scan was stopped because GLOB_ERR was set or (*errfunc()) returned non-
zero.
GLOB_NOMATCH
The pattern does not match any existing pathname, and GLOB_NOCHECK was not
set in flags.
GLOB_NOSPACE
An attempt to allocate memory failed.
The following sections are informative.
EXAMPLES
One use of the GLOB_DOOFFS flag is by applications that build an argument list for
use with execv(), execve(), or execvp(). Suppose, for example, that an application
wants to do the equivalent of:
ls -l *.c
but for some reason:
system("ls -l *.c")
is not acceptable. The application could obtain approximately the same result using
the sequence:
globbuf.gl_offs = 2;
glob("*.c", GLOB_DOOFFS, NULL, &globbuf);
globbuf.gl_pathv[0] = "ls";
globbuf.gl_pathv[1] = "-l";
execvp("ls", &globbuf.gl_pathv[0]);
Using the same example:
ls -l *.c *.h
could be approximately simulated using GLOB_APPEND as follows:
globbuf.gl_offs = 2;
glob("*.c", GLOB_DOOFFS, NULL, &globbuf);
glob("*.h", GLOB_DOOFFS|GLOB_APPEND, NULL, &globbuf);
...
APPLICATION USAGE
This function is not provided for the purpose of enabling utilities to perform
pathname expansion on their arguments, as this operation is performed by the shell,
and utilities are explicitly not expected to redo this. Instead, it is provided for
applications that need to do pathname expansion on strings obtained from other
sources, such as a pattern typed by a user or read from a file.
If a utility needs to see if a pathname matches a given pattern, it can use
fnmatch().
Note that gl_pathc and gl_pathv have meaning even if glob() fails. This allows
glob() to report partial results in the event of an error. However, if gl_pathc is
0, gl_pathv is unspecified even if glob() did not return an error.
The GLOB_NOCHECK option could be used when an application wants to expand a path-
name if wildcards are specified, but wants to treat the pattern as just a string
otherwise. The sh utility might use this for option-arguments, for example.
The new pathnames generated by a subsequent call with GLOB_APPEND are not sorted
together with the previous pathnames. This mirrors the way that the shell handles
pathname expansion when multiple expansions are done on a command line.
Applications that need tilde and parameter expansion should use wordexp().
RATIONALE
It was claimed that the GLOB_DOOFFS flag is unnecessary because it could be simu-
lated using:
new = (char **)malloc((n + pglob->gl_pathc + 1)
* sizeof(char *));
(void) memcpy(new+n, pglob->gl_pathv,
pglob->gl_pathc * sizeof(char *));
(void) memset(new, 0, n * sizeof(char *));
free(pglob->gl_pathv);
pglob->gl_pathv = new;
However, this assumes that the memory pointed to by gl_pathv is a block that was
separately created using malloc(). This is not necessarily the case. An application
should make no assumptions about how the memory referenced by fields in pglob was
allocated. It might have been obtained from malloc() in a large chunk and then
carved up within glob(), or it might have been created using a different memory
allocator. It is not the intent of the standard developers to specify or imply how
the memory used by glob() is managed.
The GLOB_APPEND flag would be used when an application wants to expand several dif-
ferent patterns into a single list.
FUTURE DIRECTIONS
None.
SEE ALSO
exec() , fnmatch() , opendir() , readdir() , stat() , wordexp() , the Base Defini-
tions volume of IEEE Std 1003.1-2001, <glob.h>, the Shell and Utilities volume of
IEEE Std 1003.1-2001
COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form from IEEE Std
1003.1, 2003 Edition, Standard for Information Technology -- Portable Operating
System Interface (POSIX), The Open Group Base Specifications Issue 6, Copyright (C)
2001-2003 by the Institute of Electrical and Electronics Engineers, Inc and The
Open Group. In the event of any discrepancy between this version and the original
IEEE and The Open Group Standard, the original IEEE and The Open Group Standard is
the referee document. The original Standard can be obtained online at
http://www.opengroup.org/unix/online.html .
POSIX 2003 GLOB(P)
Generated by $Id: phpMan.php,v 4.55 2007/09/05 04:42:51 chedong Exp $ Author: Che Dong
On Apache/1.3.41 (Unix) PHP/5.2.5 mod_perl/1.30 mod_gzip/1.3.26.1a
Under GNU General Public License
2008-12-02 08:07 @38.103.63.58 CrawledBy CCBot/1.0 (+http://www.commoncrawl.org/bot.html)