ac_as_dirname

AC_AS_DIRNAME (PATH) this is the macro AS_DIRNAME from autoconf 2.4x defined here for use in autoconf 2.1x, remove the AC_ when you use 2.4x

AC_DEFUN([AC_ECHO_MKFILE],
[dnl
  case $2 in
    */*) P=` AC_AS_DIRNAME($2) ` ; AC_AS_MKDIR_P($P) ;;
  esac
  echo "$1" >$2
])

AC_DEFUN([AC_AS_DIRNAME],
[AC_AS_DIRNAME_EXPR([$1]) 2>/dev/null ||
AC_AS_DIRNAME_SED([$1])
])


# _AC_AS_EXPR_PREPARE
# ----------------
# Some expr work properly (i.e. compute and issue the right result),
# but exit with failure.  When a fall back to expr (as in AS_DIRNAME)
# is provided, you get twice the result.  Prevent this.
AC_DEFUN([_AC_AS_EXPR_PREPARE],
[if expr a : '\(a\)' >/dev/null 2>&1; then
  as_expr=expr
else
  as_expr=false
fi
])# _AC_AS_EXPR_PREPARE


# AS_DIRNAME(PATHNAME)
# --------------------
# Simulate running `dirname(1)' on PATHNAME, not all systems have it.
# This macro must be usable from inside ` `.
#
# Prefer expr to echo|sed, since expr is usually faster and it handles
# backslashes and newlines correctly.  However, older expr
# implementations (e.g. SunOS 4 expr and Solaris 8 /usr/ucb/expr) have
# a silly length limit that causes expr to fail if the matched
# substring is longer than 120 bytes.  So fall back on echo|sed if
# expr fails.
#
# FIXME: Please note the following m4_require is quite wrong: if the first
# occurrence of AS_DIRNAME_EXPR is in a backquoted expression, the
# shell will be lost.  We might have to introduce diversions for
# setting up an M4sh script: required macros will then be expanded there.

AC_DEFUN([AC_AS_DIRNAME_EXPR],
[AC_REQUIRE([_AC_AS_EXPR_PREPARE])dnl
$as_expr X[]$1 : 'X\(.*[[^/]]\)//*[[^/][^/]]*/*$' \| \
         X[]$1 : 'X\(//\)[[^/]]' \| \
         X[]$1 : 'X\(//\)$' \| \
         X[]$1 : 'X\(/\)' \| \
         .     : '\(.\)'])

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