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GLOB(3) Linux Programmer's Manual GLOB(3)

NAME

     glob,  globfree  -  find pathnames matching a pattern, free memory from
     glob()

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 glob() function searches for all  the  pathnames  matching  pattern
     according  to  the  rules  used  by  the shell (see glob(7)).  No tilde
     expansion or parameter substitution is done; if  you  want  these,  use
     wordexp(3).

     The globfree() function frees the dynamically allocated storage from an
     earlier call to glob().

     The results of a glob() call are stored in the structure pointed to  by
     pglob.   This  structure  is  of type glob_t (declared in <glob.h>) and
     includes the following elements defined by POSIX.2 (more may be present
     as an extension):

         typedef struct {
             size_t   gl_pathc;    /* Count of paths matched so far  */
             char   **gl_pathv;    /* List of matched pathnames.  */
             size_t    gl_offs;      /*  Slots to reserve in gl_pathv.  */ }
         glob_t;

     Results are stored in dynamically allocated storage.

     The argument flags is made up of the bitwise OR of  zero  or  more  the
     following symbolic constants, which modify the behavior of glob():

     GLOB_ERR
            Return upon a read error (because a directory does not have read
            permission, for example).  By default, glob() attempts carry  on
            despite errors, reading all of the directories that it can.

     GLOB_MARK
            Append a slash to each path which corresponds to a directory.

     GLOB_NOSORT
            Don't  sort  the returned pathnames.  The only reason to do this
            is to save processing time.  By default, the returned  pathnames
            are sorted.

     GLOB_DOOFFS
            Reserve  pglob->gl_offs  slots  at  the beginning of the list of
            strings in pglob->pathv.  The reserved slots contain null point-
            ers.

     GLOB_NOCHECK
            If no pattern matches, return the original pattern.  By default,
            glob() returns GLOB_NOMATCH if there are no matches.

     GLOB_APPEND
            Append the results  of  this  call  to  the  vector  of  results
            returned  by a previous call to glob().  Do not set this flag on
            the first invocation of glob().

     GLOB_NOESCAPE
            Don't allow backslash ('\') to be used as an  escape  character.
            Normally, a backslash can be used to quote the following charac-
            ter, providing a mechanism  to  turn  off  the  special  meaning
            metacharacters.

     flags  may  also include any of the following, which are GNU extensions
     and not defined by POSIX.2:

     GLOB_PERIOD
            Allow a leading period to  be  matched  by  metacharacters.   By
            default, metacharacters can't match a leading period.

     GLOB_ALTDIRFUNC
            Use alternative functions pglob->gl_closedir, pglob->gl_readdir,
            pglob->gl_opendir,  pglob->gl_lstat,  and   pglob->gl_stat   for
            filesystem access instead of the normal library functions.

     GLOB_BRACE
            Expand  csh(1) style brace expressions of the form {a,b}.  Brace
            expressions can be nested.  Thus, for  example,  specifying  the
            pattern  "{foo/{,cat,dog},bar}" would return the same results as
            four separate glob() calls using the strings: "foo/", "foo/cat",
            "foo/dog", and "bar".

     GLOB_NOMAGIC
            If  the  pattern  contains  no metacharacters, then it should be
            returned as the sole matching word, even if  there  is  no  file
            with that name.

     GLOB_TILDE
            Carry out tilde expansion.  If a tilde ('~') is the only charac-
            ter in the pattern, or an initial tilde is followed  immediately
            by  a slash ('/'), then the home directory of the caller is sub-
            stituted for the tilde.  If an initial tilde is  followed  by  a
            username  (e.g., "~andrea/bin"), then the tilde and username are
            substituted by the home directory of that user.  If the username
            is  invalid, or the home directory cannot be determined, then no
            substitution is performed.

     GLOB_TILDE_CHECK
            This provides behavior similar to that of GLOB_TILDE.  The  dif-
            ference  is  that if the username is invalid, or the home direc-
            tory cannot be determined, then instead  of  using  the  pattern
            itself  as  the name, glob() returns GLOB_NOMATCH to indicate an
            error.

     GLOB_ONLYDIR
            This is a hint to glob() that the caller is interested  only  in
            directories  that  match the pattern.  If the implementation can
            easily determine file-type information, then nondirectory  files
            are  not returned to the caller.  However, the caller must still
            check that returned files are directories.  (The purpose of this
            flag is merely to optimize performance when the caller is inter-
            ested only in directories.)

     If errfunc is not NULL, it will be called in case of an error with  the
     arguments  epath,  a  pointer to the path which failed, and eerrno, the
     value of errno as returned from one of the calls to  opendir(3),  read-
     dir(3), or stat(2).  If errfunc returns nonzero, or if GLOB_ERR is set,
     glob() will terminate after the call to errfunc.

     Upon successful return, pglob->gl_pathc contains the number of  matched
     pathnames  and pglob->gl_pathv contains a pointer to the list of point-
     ers to matched pathnames.  The list of pointers is terminated by a null
     pointer.

     It  is  possible  to  call  glob()  several  times.   In that case, the
     GLOB_APPEND flag has to be set in flags on the second and later invoca-
     tions.

     As a GNU extension, pglob->gl_flags is set to the flags specified, ored
     with GLOB_MAGCHAR if any metacharacters were found.

RETURN VALUE

     On successful completion, glob() returns zero.  Other possible  returns
     are:

     GLOB_NOSPACE
            for running out of memory,

     GLOB_ABORTED
            for a read error, and

     GLOB_NOMATCH
            for no found matches.

ATTRIBUTES

     For   an   explanation   of   the  terms  used  in  this  section,  see
     attributes(7).

     allbox; lb  lb  lbw24  l  l  l.   Interface Attribute Value  T{  glob()
     T}   Thread safety     T{ MT-Unsafe race:utent env
     sig:ALRM timer locale T} T{ globfree() T}   Thread safety  MT-Safe

     In  the  above  table, utent in race:utent signifies that if any of the
     functions setutent(3), getutent(3), or endutent(3) are used in parallel
     in different threads of a program, then data races could occur.  glob()
     calls those functions, so we use race:utent to remind users.

CONFORMING TO

     POSIX.1-2001, POSIX.1-2008, POSIX.2.

NOTES

     The structure elements gl_pathc and gl_offs are declared as  size_t  in
     glibc  2.1, as they should be according to POSIX.2, but are declared as
     int in glibc 2.0.

BUGS

     The glob() function may fail due  to  failure  of  underlying  function
     calls,  such  as malloc(3) or opendir(3).  These will store their error
     code in errno.

EXAMPLE

     One example of use is the following code, which simulates typing

         ls -l *.c ../*.c

     in the shell:

         glob_t globbuf;

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