glob(3C)

NAME

glob(), globfree() — file name generation function

SYNOPSIS

#include <glob.h> 

int glob( 
     const char *__restrict pattern, 
     int flags, 
     int (*errfunc)(const char *, int), 
     glob_t *__restrict pglob 
); 

void globfree(glob_t *pglob); 

DESCRIPTION

glob() is a path name generator. pattern is a pointer to a path name pattern to be expanded. If pattern contains any of the special characters *, ?, or [, pattern is matched against all accessible path names. In order to have access to a path name, glob() requires:

Search permission on every component of a path except the last.
Read permission on each directory of any file name component of pattern that contains any of the above special characters.

glob() stores the number of matched path names in pglob -> gl_pathc and a pointer to a sorted list of path names in pglob->gl_pathv. The first pointer after the last path name is a NULL pointer.

It is the caller's responsibility to allocate space for the structure pointed to by pglob. glob() allocates other space as needed, including the memory pointed to by gl_pathv. globfree() 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 the bit-wise inclusive OR of the following constants defined in <glob.h>:

GLOB_NOESCAPE

Disable backslash escaping.

GLOB_ERR

Causes glob() to return when it first encounters a directory that it cannot open or read. Ordinarily, glob() continues to find matches.

GLOB_MARK

Each path name that matches pattern and is a directory, has a / appended.

GLOB_NOSORT

Ordinarily, glob() sorts the matching path names according to the currently active collation sequence as defined by the LC_COLLATE category. When this flag is used, the order of path names returned is unspecified.

GLOB_NOCHECK

If pattern does not match any path name, glob() returns a list consisting of only pattern, and the number of matched path names is 1.

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 points to pglob->gl_offs NULL pointers, followed by pglob->gl_pathc path name pointers, followed by a NULL pointer.

GLOB_APPEND

Append path names generated to the ones from a previous call to glob().

The GLOB_APPEND flag can be used to append a new set of path names 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 call must not set GLOB_APPEND. All subsequent calls must set it.
All of 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 GOB_DOOFFS and pglob->gl_offs.
- Pointers to the path names that were in the pglob->gl_pathv list before the call, in the same order as before.
- Pointers to the new path names generated by the second call, in the specified order.
The count returned in pglob->gl_pathc will be the total number of path names 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 NULL, glob() calls (*errfunc)() with two arguments:

A pointer to the path that failed.
The value of errno from the failure.

If errfunc is called and returns nonzero, 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 NULL or (*errfunc)() returns zero, the error is ignored.

Pattern Matching Notation

The form of the patterns is the Pattern Matching Notation as qualified for Filename Expansion (see regexp(5)) with the following exceptions:

Tilde (~) expansion is not performed.
Variable expansion is not performed.

EXTERNAL INFLUENCES

Locale

The LC_COLLATE category determines the collating sequence used in compiling and executing regular expressions, and also the order of the returned paths if GLOB_NOSORT is not selected.

The LC_CTYPE category determines the interpretation of text as single byte and/or multibyte characters, and determines which characters are matched by character class expressions in regular expressions.

International Code Set Support

Single byte and multibyte character code sets are supported.

RETURN VALUE

If glob() terminates due to an error, it returns one of the following constants (defined in <glob.h>); otherwise, it returns zero.

GLOB_NOSPACE: An attempt to allocate memory failed.
GLOB_ABORTED: The scan was stopped because GLOB_ERR was set or (*errfunc)() returned nonzero.
GLOB_NOMATCH: The pattern does not match any existing path name, and GLOB_NOCHECK was not set in flags.

In any case, the argument pglob->gl_pathc returns the number of matched path names and the argument pglob->gl_pathv contains a pointer to a null-terminated list of matched and sorted path names.

However, if pglob->gl_pathc is zero, the content of pglob->gl_pathv is undefined.

If the pattern argument passed to glob() is badly constructed, glob() returns zero and sets gl_pathc to zero unless GLOB_NOCHECK was set, in which case pattern is returned and gl_pathc is set to 1.

WARNINGS

GLOB_APPEND must not be set in an initial call to glob().

AUTHOR

glob() and globfree() were developed by OSF and HP.

STANDARDS CONFORMANCE

glob(): XPG4, POSIX.2

globfree(): XPG4, POSIX.2