glob(3G)
glob - generate pathnames matching a pattern
As shipped in IRIX 6.5.22. Last changed in IRIX 6.5.15.
NAME glob - generate pathnames matching a pattern 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 structure type glob_t is defined in the header <glob.h> and includes at least the following members: MemberType MemberName Description _______________________________________________________________ size_t gl_offs Slots to reserve at start of gl_pathv. char ** gl_pathv Pointer to list of matched pathnames. size_t gl_pathc Count of paths matched by pattern. The argument pattern is a pointer to a pathname pattern to be expanded. The glob function 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 characters: * ? [ The glob function 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 undetermined. It is the caller's responsibility to create the structure pointed to by glob. glob allocates other space as needed, including the memory pointed to by gl_pathv. The globfree function frees any space associated with glob from a previous call to glob. The flags argument is used to control the behaviour 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 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 will point to pglob->gl_offs null pointers, followed by pglob->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_NOCHECK If pattern does not match any pathname, then glob returns a list consisting of only pattern, and the number of matched pathnames is one (1). GLOB_NOESCAPE Disable backslash escaping. GLOB_NOSORT Ordinarily, glob sorts the matching pathnames according to the current setting of the LC_COLLATE category. When this flag is used the order of pathnames returned is unspecified. GLOB_LIMIT Limit the amount of memory used by matches to {ARG_MAX} [see sysconf(2)]. This option should be set for programs that can be coerced to a denial of service attack via patterns that expand to a very large number of matches. 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 when two or more calls to glob are made with the same value of pglob and without intervening calls to globfree: The first such call must not set GLOB_APPEND. All subsequent calls must set it. All the calls must set GLOB_DOOFFS, or all must not set it. After the second call, pglob->gl_pathv points to a list containing the following: Zero or more null pointers, as specified by GLOB_DOOFFS and pglob->gl_offs. Pointers to the pathnames that were in the pglob->gl_pathv list before the call, in the same order as before. Pointers to the new pathnames generated by the second call, in the specified order. The count returned in pglob->gl_pathc will be the total number of pathnames from the two calls. The application can change any of the fields after a call to glob. If it does, it must reset them to the original value before a subsequent 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: The epath argument is a pointer to the path that failed. The eerrno argument is the value of errno from that failure, as set by opendir(), readdir() or stat(). (Other values may be used to report other errors not explicitly documented for those functions.) The following constants are defined as error return values for glob: 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, or if errno was 0, GLOB_LIMIT was specified in the flags and the amount of memory required for the matched patterns exceeded {ARG_MAX}. 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_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. RETURN VALUE On successful completion, glob returns zero. The argument pglob->gl_pathc returns the number of matched pathnames and the argument pglob->gl_pathv contains a pointer to a null-terminated list of matched and sorted pathnames. However, if pglob->gl_pathc is zero, the contents of pglob->gl_pathv is undefined. 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. 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"; execp ("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 the 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 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 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 sheel handles pathname expansion when multiple expansions are done on a command line. Applications that need tilde and parameter expansion should use wordexp. SEE ALSO execv(2), fnmatch(3g), opendir(3b), readdir(3b), stat(2), wordexp(3g), <glob.h>.