#!/bin/sh
# Portable System Interface Copyright (c) 1997-1998 Tycho Softworks.
# $Id: isusr 1.1 Tue, 23 Jun 1998 11:38:33 -0400 dyfet $

if test -z "$*" ; then
	if test -f /etc/passwd
		echo 'true'
	else
		echo 'false'
	fi
	exit 0
fi

for usr in $* ; do
	grep ^"$usr": /etc/passwd >/dev/null
	if test ! $? = 1 ; then
		echo $usr
		exit 0
	fi
done
echo $usr

	
