##### http://autoconf-archive.cryp.to/ac_check_user.html
#
# SYNOPSIS
#
#   AC_CHECK_USER
#
# DESCRIPTION
#
#   Check if the specified UNIX user exists, if yes set your
#   environment variable to that username else unset your environment
#   variable
#
#   Example:
#
#       AC_CHECK_USER(USER, [gleensalmon])
#       if test x$USER = xgleensalmon; then
#           bla..bla..bla..
#       else
#           bla..bla..bla..
#       fi
#
#   Besides checking existence, this macro also set these environment
#   variables upon completion:
#
#       USER_HOME = home directory of user, written in /etc/passwd
#
# LAST MODIFICATION
#
#   2002-04-11
#
# COPYLEFT
#
#   Copyright (c) 2002 Gleen Salmon <gleensalmon@yahoo.com>
#
#   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.
#
#   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 Macro 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.

AC_DEFUN([AC_CHECK_USER],[
AC_MSG_CHECKING([for user $2])
if grep ^$2: /etc/passwd > /dev/null; then
        $1=$2
        USER_HOME=`grep ^$2: /etc/passwd | sed "s/^\([[^:]]*:\)\{5\}\([[^:]]*\):[[^:]]*$/\2/"`
        AC_MSG_RESULT([yes])
else
        unset $1
        unset USER_HOME
        AC_MSG_RESULT([no])
fi;dnl
])