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, 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 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 parameter flags is made up of bitwise OR
of zero or more the following symbolic constants, which
modify the of behavior of glob():
GLOB_ERRwhich means to return upon read error (because a directory does not have read permission, for example),
GLOB_MARKwhich means to append a slash to each path which corresponds to a directory,
GLOB_NOSORTwhich means don't sort the returned pathnames (they are by default),
GLOB_DOOFFSwhich means that pglob->gl_offs slots
will be reserved at the beginning of the list of
strings in pglob->pathv,
GLOB_NOCHECKwhich means that, if no pattern matches, to return the original pattern,
GLOB_APPENDwhich means to append to the results of a previous
call. Do not set this flag on the first invocation of
glob().
GLOB_NOESCAPEwhich 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_PERIODwhich means that a leading period can be matched by meta characters,
GLOB_ALTDIRFUNCwhich 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_BRACEwhich means that csh(1) style brace
expressions {a,b} are expanded,
GLOB_NOMAGICwhich means that the pattern is returned if it contains no metacharacters,
GLOB_TILDEwhich means that tilde expansion is carried out, and
GLOB_ONLYDIRwhich 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(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 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.
On successful completion, glob() returns zero. Other possible returns
are:
GLOB_NOSPACEfor running out of memory,
GLOB_ABORTEDfor a read error, and
GLOB_NOMATCHfor no found matches.
The structure elements gl_pathc and gl_offs are declared as
size_t in glibc
2.1, as they should according to POSIX.2, but are declared as
int in libc4, libc5
and 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)
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