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DIRNAME(3P)                POSIX Programmer's Manual               DIRNAME(3P)
PROLOG
       This  manual  page is part of the POSIX Programmer's Manual.  The Linux
       implementation of this interface may differ (consult the  corresponding
       Linux  manual page for details of Linux behavior), or the interface may
       not be implemented on Linux.
NAME
       dirname -- report the parent directory name of a file pathname
SYNOPSIS
       #include <libgen.h>
       char *dirname(char *path);
DESCRIPTION
       The dirname() function shall take a pointer to a character string  that
       contains  a  pathname, and return a pointer to a string that is a path-
       name of the parent directory of that file. Trailing '/'  characters  in
       the path are not counted as part of the path.
       If  path  does not contain a '/', then dirname() shall return a pointer
       to the string ".".  If path is a null pointer or  points  to  an  empty
       string, dirname() shall return a pointer to the string ".".
       The dirname() function need not be thread-safe.
RETURN VALUE
       The  dirname()  function shall return a pointer to a string that is the
       parent directory of path.  If path is a null pointer or  points  to  an
       empty string, a pointer to a string "." is returned.
       The  dirname()  function  may modify the string pointed to by path, and
       may return a pointer to internal storage. The returned pointer might be
       invalidated or the storage might be overwritten by a subsequent call to
       dirname().
ERRORS
       No errors are defined.
       The following sections are informative.
EXAMPLES
       The following code fragment reads a pathname, changes the current work-
       ing directory to the parent directory, and opens the file.
           char *path = NULL, *pathcopy;
           size_t buflen = 0;
           ssize_t linelen = 0;
           int fd;
           linelen = getline(&path, &buflen, stdin);
           path[linelen-1] = 0;
           pathcopy = strdup(path);
           if (chdir(dirname(pathcopy)) < 0) {
               ...
           }
           if ((fd = open(basename(path), O_RDONLY)) >= 0) {
               ...
               close (fd);
           }
           ...
           free (pathcopy);
           free (path);
   Sample Input and Output Strings for dirname()
       In  the  following  table,  the input string is the value pointed to by
       path, and the output string is the return value of the dirname()  func-
       tion.
                           +-------------+---------------+
                           |Input String | Output String |
                           +-------------+---------------+
                           |"/usr/lib"   | "/usr"        |
                           |"/usr/"      | "/"           |
                           |"usr"        | "."           |
                           |"/"          | "/"           |
                           |"."          | "."           |
                           |".."         | "."           |
                           +-------------+---------------+
APPLICATION USAGE
       The  dirname() and basename() functions together yield a complete path-
       name. The expression dirname(path) obtains the pathname of  the  direc-
       tory where basename(path) is found.
       Since  the  meaning  of  the  leading  "//"  is implementation-defined,
       dirname("//foo) may return either "//" or '/' (but nothing else).
RATIONALE
       None.
FUTURE DIRECTIONS
       None.
SEE ALSO
       basename()
       The Base Definitions volume of POSIX.1-2008, <libgen.h>
COPYRIGHT
       Portions of this text are reprinted and reproduced in  electronic  form
       from IEEE Std 1003.1, 2013 Edition, Standard for Information Technology
       -- Portable Operating System Interface (POSIX),  The  Open  Group  Base
       Specifications Issue 7, Copyright (C) 2013 by the Institute of Electri-
       cal and Electronics Engineers,  Inc  and  The  Open  Group.   (This  is
       POSIX.1-2008  with  the  2013  Technical Corrigendum 1 applied.) In the
       event of any discrepancy between this version and the original IEEE and
       The  Open Group Standard, the original IEEE and The Open Group Standard
       is the referee document. The original Standard can be  obtained  online
       at http://www.unix.org/online.html .
       Any  typographical  or  formatting  errors that appear in this page are
       most likely to have been introduced during the conversion of the source
       files  to  man page format. To report such errors, see https://www.ker-
       nel.org/doc/man-pages/reporting_bugs.html .
IEEE/The Open Group                  2013                          DIRNAME(3P)