int glob(const char *pattern, int flags, int (*errfunc)(const char *epath, int eerrno), glob_t *pglob);
void globfree(glob_t *pglob);
The structure type glob_t is defined in the header <glob_h>.
pattern is a pointer to a pathname pattern to be expanded. glob matches all accessible pathnames against this pattern and develops 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:
* ? [
glob stores 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 are in sort order as defined by the current setting of the LC_COLLATE category. The first pointer after the last pathname is a null pointer. If the pattern does not match any pathnames, the returned number of matched paths is set to zero, and the contents of pglob-> gl_pathv are undefined.
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 globfree function frees 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 the header <glob.h>:
GLOB_APPEND can be used to append a new set of pathnames to those found in a previous call to glob. The following rules apply when two or more calls to glob are made with the same value of pglob and without intervening calls to globfree.
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:
The globfree function returns no value.
If glob terminates due to an error, it returns 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.
If (*errfunc) is called and returns non-zero, or if the GLOB_ERR flag is set in flags, glob stops the scan and returns 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 zero, the error is ignored.
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 zero, 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 pathname if wildcards are specified, but wants to treat the pattern as just a string otherwise.
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.
ls -l *.cbut 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 = "ls"; globbuf.gl_pathv = "-l"; execvp ("ls", &globbuf.gl_pathv);Using the same example:
ls -l *.c *.hcould 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); ...