path: root/newlib/libc/posix/glob.3

GLOB(3)                            BSD Library Functions Manual                           GLOB(3)

NAME
     glob, globfree -- generate pathnames matching a pattern

LIBRARY
     Standard C Library (libc, -lc)

SYNOPSIS
     #include <glob.h>

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

     void
     globfree(glob_t *pglob);

DESCRIPTION
     The glob() function is a pathname generator that implements the rules for file name pattern
     matching used by the shell.

     The include file glob.h defines the structure type glob_t, which contains at least the fol-
     lowing fields:

     typedef struct {
             int gl_pathc;           /* count of total paths so far */
             int gl_matchc;          /* count of paths matching pattern */
             int gl_offs;            /* reserved at beginning of gl_pathv */
             int gl_flags;           /* returned flags */
             char **gl_pathv;        /* list of paths matching pattern */
     } glob_t;

     The argument pattern is a pointer to a pathname pattern to be expanded.  The glob() argument
     matches all accessible pathnames against the pattern and creates a list of the pathnames
     that match.  In order to have access to a pathname, glob() requires search permission on ev-
     ery component of a path except the last and read permission on each directory of any file-
     name component of pattern that contains any of the special characters '*', '?' or '['.

     The glob() argument stores the number of matched pathnames into the gl_pathc field, and a
     pointer to a list of pointers to pathnames into the gl_pathv field.  The first pointer after
     the last pathname is NULL.  If the pattern does not match any pathnames, the returned number
     of matched paths is set to zero.

     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 argument flags is used to modify the behavior of glob().  The value of flags is the bit-
     wise inclusive OR of any of the following values defined in glob.h:

     GLOB_APPEND      Append pathnames generated to the ones from a previous call (or calls) to
                      glob().  The value of gl_pathc will be the total matches found by this call
                      and the previous call(s).  The pathnames are appended to, not merged with
                      the pathnames returned by the previous call(s).  Between calls, the caller
                      must not change the setting of the GLOB_DOOFFS flag, nor change the value
                      of gl_offs when GLOB_DOOFFS is set, nor (obviously) call globfree() for
                      pglob.

     GLOB_DOOFFS      Make use of the gl_offs field.  If this flag is set, gl_offs is used to
                      specify how many NULL pointers to prepend to the beginning of the gl_pathv
                      field.  In other words, gl_pathv will point to gl_offs NULL pointers, fol-
                      lowed by 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 ap-
                      pended.

     GLOB_NOCHECK     If pattern does not match any pathname, then glob() returns a list consist-
                      ing of only pattern, with the number of total pathnames is set to 1, and
                      the number of matched pathnames set to 0.  If GLOB_QUOTE is set, its effect
                      is present in the pattern returned.

     GLOB_NOSORT      By default, the pathnames are sorted in ascending ASCII order; this flag
                      prevents that sorting (speeding up glob()).

     The following values may also be included in flags, however, they are non-standard exten-
     sions to IEEE Std 1003.2 ("POSIX.2").

     GLOB_ALTDIRFUNC  The following additional fields in the pglob structure have been initial-
                      ized with alternate functions for glob to use to open, read, and close di-
                      rectories and to get stat information on names found in those directories.

                      void *(*gl_opendir)(const char * name);
                      struct dirent *(*gl_readdir)(void *);
                      void (*gl_closedir)(void *);
                      int (*gl_lstat)(const char *name, struct stat *st);
                      int (*gl_stat)(const char *name, struct stat *st);

                      This extension is provided to allow programs such as restore(8) to provide
                      globbing from directories stored on tape.

     GLOB_BRACE       Pre-process the pattern string to expand '{pat,pat,...}' strings like
                      csh(1).  The pattern '{}' is left unexpanded for historical reasons (and
                      csh(1) does the same thing to ease typing of find(1) patterns).

     GLOB_MAGCHAR     Set by the glob() function if the pattern included globbing characters.
                      See the description of the usage of the gl_matchc structure member for more
                      details.

     GLOB_NOMAGIC     Is the same as GLOB_NOCHECK but it only appends the pattern if it does not
                      contain any of the special characters ``*'', ``?'' or ``[''.  GLOB_NOMAGIC
                      is provided to simplify implementing the historic csh(1) globbing behavior
                      and should probably not be used anywhere else.

     GLOB_QUOTE       Use the backslash ('\') character for quoting: every occurrence of a back-
                      slash followed by a character in the pattern is replaced by that character,
                      avoiding any special interpretation of the character.

     GLOB_TILDE       Expand patterns that start with '~' to user name home directories.

     GLOB_LIMIT       Limit the total number of returned pathnames to the value provided in
                      gl_matchc (default ARG_MAX).  This option should be set for programs that
                      can be coerced into a denial of service attack via patterns that expand to
                      a very large number of matches, such as a long string of '*/../*/..'.

     If, during the search, a directory is encountered that cannot be opened or read and errfunc
     is non-NULL, glob() calls (*errfunc)(path, errno).  This may be unintuitive: a pattern like
     '*/Makefile' will try to stat(2) 'foo/Makefile' even if 'foo' is not a directory, resulting
     in a call to errfunc.  The error routine can suppress this action by testing for ENOENT and
     ENOTDIR; however, the GLOB_ERR flag will still cause an immediate return when this happens.

     If errfunc returns non-zero, glob() stops the scan and returns GLOB_ABEND after setting
     gl_pathc and gl_pathv to reflect any paths already matched.  This also happens if an error
     is encountered and GLOB_ERR is set in flags, regardless of the return value of errfunc, if
     called.  If GLOB_ERR is not set and either errfunc is NULL or errfunc returns zero, the er-
     ror is ignored.

     The globfree() function frees any space associated with pglob from a previous call(s) to
     glob().

RETURN VALUES
     On successful completion, glob() returns zero.  In addition the fields of pglob contain the
     values described below:

     gl_pathc      contains the total number of matched pathnames so far.  This includes other
                   matches from previous invocations of glob() if GLOB_APPEND was specified.

     gl_matchc     contains the number of matched pathnames in the current invocation of glob().

     gl_flags      contains a copy of the flags parameter with the bit GLOB_MAGCHAR set if
                   pattern contained any of the special characters ``*'', ``?'' or ``['', cleared
                   if not.

     gl_pathv      contains a pointer to a NULL-terminated list of matched pathnames.  However,
                   if gl_pathc is zero, the contents of gl_pathv are undefined.

     If glob() terminates due to an error, it sets errno and returns one of the following non-
     zero constants, which are defined in the include file <glob.h>:

     GLOB_NOSPACE  An attempt to allocate memory failed, or if errno was 0 GLOB_LIMIT was speci-
                   fied in the flags and pglob->gl_matchc or more patterns were matched.

     GLOB_ABEND    The scan was stopped because an error was encountered and either GLOB_ERR was
                   set or (*errfunc)() returned non-zero.

     The arguments pglob->gl_pathc and pglob->gl_pathv are still set as specified above.

EXAMPLES
     A rough equivalent of 'ls -l *.c *.h' can be obtained with the following code:

           glob_t g;

           g.gl_offs = 2;
           glob("*.c", GLOB_DOOFFS, NULL, &g);
           glob("*.h", GLOB_DOOFFS | GLOB_APPEND, NULL, &g);
           g.gl_pathv[0] = "ls";
           g.gl_pathv[1] = "-l";
           execvp("ls", g.gl_pathv);

SEE ALSO
     sh(1), fnmatch(3), regexp(3)

STANDARDS
     The glob() function is expected to be IEEE Std 1003.2 ("POSIX.2") compatible with the excep-
     tion that the flags GLOB_ALTDIRFUNC, GLOB_BRACE, GLOB_LIMIT, GLOB_MAGCHAR, GLOB_NOMAGIC,
     GLOB_QUOTE, and GLOB_TILDE, and the fields gl_matchc and gl_flags should not be used by ap-
     plications striving for strict POSIX conformance.

HISTORY
     The glob() and globfree() functions first appeared in 4.4BSD.

BUGS
     Patterns longer than MAXPATHLEN may cause unchecked errors.

     The glob() argument may fail and set errno for any of the errors specified for the library
     routines stat(2), closedir(3), opendir(3), readdir(3), malloc(3), and free(3).

BSD                                       April 16, 1994                                      BSD