curl/ares/m4/cares-system.m4

#***************************************************************************
# $Id$
#
# Copyright (C) 2008 by Daniel Stenberg et al
#
# Permission to use, copy, modify, and distribute this software and its
# documentation for any purpose and without fee is hereby granted, provided
# that the above copyright notice appear in all copies and that both that
# copyright notice and this permission notice appear in supporting
# documentation, and that the name of M.I.T. not be used in advertising or
# publicity pertaining to distribution of the software without specific,
# written prior permission.  M.I.T. makes no representations about the
# suitability of this software for any purpose.  It is provided "as is"
# without express or implied warranty.
#
#***************************************************************************

# File version for 'aclocal' use. Keep it a single number.
# serial 2


dnl CARES_CHECK_PATH_SEPARATOR
dnl -------------------------------------------------
dnl Check and compute the path separator for us. This
dnl path separator is the symbol used to diferentiate
dnl or separate paths inside the PATH environment var.

AC_DEFUN([CARES_CHECK_PATH_SEPARATOR], [
  if test -z "$cares_cv_PATH_SEPARATOR"; then
    if test -z "$PATH"; then
      AC_MSG_ERROR([PATH not set. Cannot continue without PATH being set.])
    fi
    dnl Directory count in PATH when using a colon separator.
    tst_dirs_col=0
    tst_save_IFS=$IFS; IFS=':'
    for tst_dir in $PATH; do
      IFS=$tst_save_IFS
      test -d "$tst_dir" && tst_dirs_col=`expr $tst_dirs_col + 1`
    done
    IFS=$tst_save_IFS
    dnl Directory count in PATH when using a semicolon separator.
    tst_dirs_sem=0
    tst_save_IFS=$IFS; IFS=';'
    for tst_dir in $PATH; do
      IFS=$tst_save_IFS
      test -d "$tst_dir" && tst_dirs_sem=`expr $tst_dirs_sem + 1`
    done
    IFS=$tst_save_IFS
    if test $tst_dirs_sem -eq $tst_dirs_col; then
      dnl When both counting methods give the same result we do not want to
      dnl chose one over the other, and consider auto-detection not possible.
      if test -z "$PATH_SEPARATOR"; then
        dnl Stop dead until user provides PATH_SEPARATOR definition.
        AC_MSG_ERROR([PATH_SEPARATOR not set. Cannot continue without it.])
      fi
    else
      dnl Separator with the greater directory count is the auto-detected one.
      if test $tst_dirs_sem -gt $tst_dirs_col; then
        tst_auto_separator=';'
      else
        tst_auto_separator=':'
      fi
      if test -z "$PATH_SEPARATOR"; then
        dnl Simply use the auto-detected one when not already set.
        PATH_SEPARATOR="$tst_auto_separator"
      fi
    fi
    cares_cv_PATH_SEPARATOR="$PATH_SEPARATOR"
  fi
  AC_SUBST([PATH_SEPARATOR])
  AC_SUBST([PATH])
])