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GLOB(3)                    Library Functions Manual                    GLOB(3)

NAME
     glob, globfree, glob_pattern_p - generate pathnames matching a pattern

LIBRARY
     Standard C Library (libc, -lc)

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);

     int
     glob_pattern_p(const char *pattern, int quote);

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 following fields:

     typedef struct {
             size_t gl_pathc;        /* count of total paths so far */
             size_t gl_matchc;       /* count of paths matching pattern */
             size_t 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 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 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 bitwise 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, followed 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 appended.

     GLOB_NOCHECK     If pattern does not match any pathname, then glob()
                      returns a list consisting of only pattern, with one
                      level of backslash escapes removed, the number of total
                      pathnames set to 1, and the number of matched pathnames
                      set to 0.

     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 extensions to IEEE Std 1003.2 ("POSIX.2").

     GLOB_ALTDIRFUNC   The following additional fields in the pglob structure
                       have been initialized with alternate functions for glob
                       to use to open, read, and close directories 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 (csh(1) does
                       the same thing to ease typing of find(1) patterns).

     GLOB_LIMIT        Limit the amount of memory used to store matched
                       strings to 64K, the number of stat(2) calls to 128, and
                       the number of readdir(3) calls to 16K.  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, such as a long string of
                       */../*/..

     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_NOESCAPE     Disable the use of the backslash (`\') character for
                       quoting.

     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_NO_DOTDIRS   Hide `.' and `..' from metacharacter matches,
                       regardless of whether GLOB_PERIOD is set and whether
                       the pattern component begins with a literal period.

     GLOB_PERIOD       Allow metacharacters to match a leading period in a
                       filename.

     GLOB_STAR         Indicates that two adjacent * characters will do a
                       recursive match in all subdirs, without following
                       symbolic links and three adjacent * characters will
                       also follow symbolic links.

     GLOB_TILDE        Expand patterns that start with `~' to user name home
                       directories.  If the user with the given user name (or
                       the user id of the current user in the case of "~/") is
                       not found, the original pattern is returned.

     GLOB_TILDE_CHECK  When used with GLOB_TILDE and the user name or the user
                       id is not found, then GLOB_NOMATCH is returned instead
                       of the original pattern.

     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_ABORTED 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 error is ignored.

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

     The glob_pattern_p() returns 1 if the pattern has any special characters
     that glob() will interpret and 0 otherwise.  If the quote argument is
     non-zero, then backslash quoted characters are ignored.

     The historical GLOB_QUOTE flag is no longer supported.  Per IEEE Std
     1003.2-1992 ("POSIX.2"), backslash escaping of special characters is the
     default behaviour; it may be disabled by specifying the GLOB_NOESCAPE
     flag.

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_ABORTED     The scan was stopped because an error was encountered
                      and either 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 ARG_MAX
                      patterns were matched.

     The historical GLOB_ABEND return constant is no longer supported.
     Portable applications should use the GLOB_ABORTED constant instead.

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

ENVIRONMENT
     HOME  If defined, used as the home directory of the current user in tilde
           expansions.

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), glob(7)

STANDARDS
     The glob() function is expected to be IEEE Std 1003.2 ("POSIX.2")
     compatible with the exception that the flags GLOB_ALTDIRFUNC, GLOB_BRACE,
     GLOB_LIMIT, GLOB_MAGCHAR, GLOB_NOESCAPE, GLOB_NOMAGIC, GLOB_NO_DOTDIRS,
     GLOB_PERIOD, GLOB_STAR, GLOB_TILDE, and the fields gl_matchc and gl_flags
     should not be used by applications striving for strict POSIX conformance.

HISTORY
     The glob() and globfree() functions first appeared in 4.4BSD.  The
     glob_pattern_p() function is modelled after the one found in glibc.

BUGS
     Patterns longer than MAXPATHLEN may cause unchecked errors.

     The glob() function 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).

NetBSD 10.99                     May 28, 2019                     NetBSD 10.99