ax_dirname.m4

# ===========================================================================
#        https://www.gnu.org/software/autoconf-archive/ax_dirname.html
# ===========================================================================
#
# SYNOPSIS
#
#   AX_DIRNAME(PATHNAME)
#
# DESCRIPTION
#
#   Parts of the implementation have been taken from AS_DIRNAME from the
#   main autoconf package in generation 2.5x. However, we do only use "sed"
#   to cut out the dirname, and we do additionally clean up some dir/..
#   parts in the resulting pattern.
#
#   this macro may be used in autoconf 2.13 scripts as well.
#
# LICENSE
#
#   Copyright (c) 2008 Guido U. Draheim <guidod@gmx.de>
#
#   This program is free software; you can redistribute it and/or modify it
#   under the terms of the GNU General Public License as published by the
#   Free Software Foundation; either version 3 of the License, or (at your
#   option) any later version.
#
#   This program is distributed in the hope that it will be useful, but
#   WITHOUT ANY WARRANTY; without even the implied warranty of
#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
#   Public License for more details.
#
#   You should have received a copy of the GNU General Public License along
#   with this program. If not, see <https://www.gnu.org/licenses/>.
#
#   As a special exception, the respective Autoconf Macro's copyright owner
#   gives unlimited permission to copy, distribute and modify the configure
#   scripts that are the output of Autoconf when processing the Macro. You
#   need not follow the terms of the GNU General Public License when using
#   or distributing such scripts, even though portions of the text of the
#   Macro appear in them. The GNU General Public License (GPL) does govern
#   all other use of the material that constitutes the Autoconf Macro.
#
#   This special exception to the GPL applies to versions of the Autoconf
#   Macro released by the Autoconf Archive. When you make and distribute a
#   modified version of the Autoconf Macro, you may extend this special
#   exception to the GPL to apply to your modified version as well.

#serial 8

AC_DEFUN([AX_DIRNAME],
[echo X[]$1 |
    sed ['s/\/[^\/:][^\/:]*\/..\//\//g
          s/\/[^\/:][^\/:]*\/..\//\//g
          s/\/[^\/:][^\/:]*\/..\//\//g
          s/\/[^\/:][^\/:]*\/..\//\//g
          /^X\(.*[^/]\)\/\/*[^/][^/]*\/*$/{ s//\1/; q; }
          /^X\(\/\/\)[^/].*/{ s//\1/; q; }
          /^X\(\/\/\)$/{ s//\1/; q; }
          /^X\(\/\).*/{ s//\1/; q; }
          s/.*/./; q']])