#!/bin/sh
# @(#)  /u/des/src/lst/lst  1.4  01/07/29  12:57:30
# lst -- ls specified file types (those recognized by `find') in
#	specified directories
#
# returns 0 for no errors and at least one match found in each dir argument;
# returns 1 if any errors, else 2 if any dirs with no matches;
#
# 12/98, D.Singer

PROG=`basename "$0"`
USAGE="Usage:  $PROG [-bcdDflps] [--h[elp]] [--l[ong]] [--o[ne]] [--] [dir...]"
# and see help message below

DFLT_TYPE='f'
TYPES=
HELP=
LONG=
ONE=
STATUS=0	# exit status

#
# environment variables
#
: ${LST_SPACE=' '}	# space to use with --o

SYNTAX="$PROG: option syntax error."

#
# platform specific settings
#
SYS="`uname -sr`"      # OS type
case "$SYS" in
  "SunOS "*)
	AWK="nawk"
	;;
  *)
	AWK="awk"
  esac

#
# do echo with newline suppression
#
_C= _N= _NC=
echon() {
	if [ ! "$_NC" ]; then
		if [ "/`echo '\c'`" = '/' ]; then
			_C='\c'
		  elif [ "/`echo -n`" = '/' ]; then
			_N='-n '
		  else
			:	# unknown
		fi 
		_NC=1
	fi
	echo $_N"$*$_C"
}

syntax_error() {
	echo "$SYNTAX" >&2
	echo "$USAGE" >&2
	exit 1
}

#arg_syntax_check() {
#	[ "$1" -lt 1 ] && syntax_error
#}

#
# process command line options and arguments
#
while [ $# != 0 ]; do
	case "$1" in
	  # options without argument
	  -b)
		TYPES="$TYPES b"
		;;
	  -c)
		TYPES="$TYPES c"
		;;
	  -d)
		TYPES="$TYPES d"
		;;
	  -D)
		TYPES="$TYPES D"
		;;
	  -f)
		TYPES="$TYPES f"
		;;
	  -l)
		TYPES="$TYPES l"
		;;
	  -p)
		TYPES="$TYPES p"
		;;
	  -s)
		TYPES="$TYPES s"
		;;
	  --h|--help)
		HELP=1
		;;
	  --l|--long)
		LONG=1
		;;
	  --o|--one)
		ONE=1
		;;
	  # options with argument
	#  -c)
	#	shift
	#	arg_syntax_check "$#"
	#	CARG="$1"
	#	CFLAG=1
	#	;;
	  # ...
	  --)
		shift
		break
		;;
	  # unknown option
	  -?)
		syntax_error
		;;
	  # compound option
	  -??*)
		# break up a compound option
		NEW_OPTS=`$AWK 'BEGIN {
			OPT_STR = "'"$1"'";
			LEN = length(OPT_STR);
			NEW_OPTS = "";
			STATUS = 0;
			for (POS=2; POS+0 <= LEN; ++POS) {
				OPT = substr(OPT_STR,POS,1);
				if (OPT !~ /[a-zA-Z0-9_]/)
					STATUS = 1;
				NEW_OPTS = NEW_OPTS " -" OPT;
			}
			print NEW_OPTS;
			exit STATUS;
		  }' <&-` || {
			syntax_error
		  }
		shift
		set -- $NEW_OPTS ${1:+"$@"}
		continue
		;;
	  # end of options, just command arguments left
	  *)
		break
	  esac
	shift
  done

if [ "$HELP" ]; then
	echo "
$PROG:

For each directory argument, list only the objects that match any
of the selected types.

$USAGE

	   -b	block-special files
	   -c	character-special files
	   -d	directories
	   -D	doors
	   -f	regular files (default)
	   -l	symbolic links
	   -p	named pipes
	   -s	sockets

	  --h	(or --help) print this help and exit
	  --l	(or --long) long listing
	  --o	(or --one) list all matches in one line

	  dir	directory to search, default is current directory

The environment variable \"LST_SPACE\" can be used to set the space
character(s) for the --o option.
"
	exit 0
  fi

#
# use the default type if no type selected
#
[ -z "$TYPES" ] && TYPES="$DFLT_TYPE"

#
# look for mutually exclusive options
#
if [ "$LONG" -a "$ONE" ]; then
	echo "$PROG: cannot use \"--l\" and \"--o\" together." >&2
	echo "$USAGE" >&2
	exit 1
  fi

#
# construct part of the 'find' expr
#
for TYPE in $TYPES; do
	[ -n "$TYPES_EXPR" ] && TYPES_EXPR="$TYPES_EXPR -o "
	TYPES_EXPR="${TYPES_EXPR}-type $TYPE"
  done
#echo "TYPES_EXPR=\"$TYPES_EXPR\""
#exit

#
# set the default directory, if necessary
#
if [ $# = 0 ]; then
	# if no command line args, use the current directory
	set -f
	set -- '.'
	set +f
  fi
NUM_DIRS=$#

#
# get the starting point
#
if [ $# -gt 1 ]; then
	START_DIR=`pwd` || {
		echo "$PROG: cannot determine current directory." >&2
		exit 1
	}
  fi

#
# process each directory
#
for DIR do
	# more verbose if multiple directories
	[ "$NUM_DIRS" != 1 ] && echo "$DIR:"

	[ -d "$DIR" ] || {
		echo "$PROG: \"$DIR\" not a directory." >&2
		[ $# -gt 1 ] && echo
		STATUS=1
		shift
		continue
	}
	[ -r "$DIR" ] || {
		echo "$PROG: directory \"$DIR\" not readable." >&2
		[ $# -gt 1 ] && echo
		STATUS=1
		shift
		continue
	}
	[ -x "$DIR" ] || {
		echo "$PROG: cannot chdir to directory \"$DIR\"." >&2
		[ $# -gt 1 ] && echo
		STATUS=1
		shift
		continue
	}

	cd "$DIR"

	#
	# get names of files with the selected type, skipping "." entry
	#
	NAMES=`find "." -name "." -o \( \( \( $TYPES_EXPR \) -print -prune \) -o -prune \) |
	  #
	  # get rid of path part, and sort entries
	  #
	  $AWK '{
		sub(".*/","");
		print;
	  }' |
	  sort
	`
#echo "NAMES=\"$NAMES\""
#exit


	#
	# output the names, or the long listings if selected
	#
	if [ -z "$NAMES" ]; then
		# status for any dirs with no matches
		[ "$STATUS" = 0 ] && STATUS=2
	  else
		if [ "$LONG" ]; then
			_IFS="$IFS"
			IFS='
'
			ls -ld `echo "$NAMES"`
			IFS="$_IFS"
		  elif [ "$ONE" ]; then
			_IFS="$IFS"
			IFS='
'
			SPACE=
			for NAME in $NAMES; do
				echon "$SPACE$NAME"
				SPACE="$LST_SPACE"
			  done
			[ "$SPACE" ] && echo
			IFS="$_IFS"
		  else
			echo "$NAMES"
		  fi
	  fi

	if [ $# -gt 1 ]; then
		#
		# get back to the starting point so that directories
		# resolve correctly
		#
		cd "$START_DIR"

		#
		# more multiple directory verboseness
		#
		echo ""
	  fi

	shift
  done

exit $STATUS