# substring function
# this function should be equivalent to the substring built-in which was
# eliminated after the 06/29/84 version
function substring
{
	typeset lpat flag str	#local variables
	set -o noglob		#no file name generation
	case $1 in
	-l|-L)
		flag=$1
		lpat=$2
		shift 2
		;;
	esac
	# test for too few or too many arguments
	if	[ x"$1" = x -o $# -gt 2 ]
	then	print -u2 'substring: bad argument count'
		return 1
	fi
	str=$1
	if	[ x"$flag" = x-l ]		#substring -l lpat
	then	str=${str#$lpat}
	elif	[ x"$flag" = x-L ]
	then	str=${str##$lpat}		#substring -L lpat
	fi
	if	[ x"$2" != x ]
	then	echo ${str%$2}
	else	echo $str
	fi
	return 0
}