##### http://autoconf-archive.cryp.to/ac_very_nice.html
#
# SYNOPSIS
#
#   AC_VERY_NICE
#
# DESCRIPTION
#
#   A macro to check the options of nice, in order to have a VERY_NICE
#   variable which runs a program at the lowest priority VERY_NICE is
#   undefined if we don't find the proper options, so you can safely
#   use:
#
#     @VERY_NICE@ mycommand
#
#   in a shell script.
#
#   The VERY_NICE variable includes the placeholder NICE_VALUE that you
#   have to instantiate at run-time. If you give a argument to
#   AC_VERY_NICE, it will be used as an argument of nice for testing
#   and included in VERY_NICE instead of the above placeholder.
#
# LAST MODIFICATION
#
#   2000-07-19
#
# COPYLEFT
#
#   Copyright (c) 2000 Stephane Bortzmeyer <bortzmeyer@pasteur.fr>
#
#   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 2 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, write to the Free Software
#   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
#   02111-1307, USA.
#
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AC_DEFUN([AC_VERY_NICE],[
if test "x$1" != "x"; then
  NICE_VALUE=$1
else
  NICE_VALUE=20
fi
AC_CHECK_PROGS(TEST_NICE, date)
AC_CHECK_PROGS(NICE, nice, )
AC_MSG_CHECKING(syntax of nice)
if test "x$NICE" != "x"; then
     if  ( $NICE -n $NICE_VALUE $TEST_NICE > /dev/null 2>&1 ) ;  then
        VERY_NICE="$NICE -n $NICE_VALUE"
     else
      if  ( $NICE -$NICE_VALUE $TEST_NICE > /dev/null 2>&1 ) ;  then
        VERY_NICE="$NICE -$NICE_VALUE"
      fi
     fi
fi
if test "x$1" = "x"; then
  VERY_NICE=`echo $VERY_NICE | sed "s/$NICE_VALUE/NICE_VALUE/"`
fi
AC_MSG_RESULT($VERY_NICE)
AC_SUBST(VERY_NICE)
])