#!/bin/sh -
# build a "symlink mask" - make symlinks to the source tree.
# inspired by the mk.links feature in BIND distributions.
# $Header: /c/src/local.bin/RCS/srclinks,v 1.29 2001/02/09 22:41:44 pkern Exp $

prog=$0
USAGE="usage: $prog [-dq] [-s <symlink-name>] [-t target-dir] source-dir [tree ...]"

# default name for the base symlink in each directory.
sym=SRC

# verbose by default.
note=echo
nonl=-n nlc=
case `uname` in
AIX)	nonl= nlc=\\c ;;
esac

# no copies by default.
copy=

while getopts c:dqs:t: c
do
	case $c in
	c) copy="$copy $OPTARG" ;;
	d) debug=y ;;
	q) note=: ;;
	s) sym=$OPTARG ;;
	t) dest="$OPTARG/" ;;
	*) echo "$USAGE" >&2 ; exit 1 ;;
	esac
done
shift `expr $OPTIND - 1`

# directories which should be symlinked instead of copied.
linked="CVS RCS DIST ORIG .ORIG"

or='('
skip=
for n in $linked ; do skip="$skip $or -name $n" ; or=" -o" ; done

# also skip over files which should be copied instead of linked.
for n in $copy ; do skip="$skip $or -name $n" ; or=" -o" ; done
skip="$skip )"

# files which should be copied instead of linked.
if [ -n "$copy" ] ; then
	or='('
	copies=
	for n in $copy
	do
		copies="$copies $or -name $n"
		or=" -o"
	done
	copies="$copies )"
fi

# if single arg is a path ...
case "$#,$1" in
1,*/*)	
	# then assume the path base is the copy source.
	b="`basename "$1"`"
	d="`dirname "$1"`"
	set - "$d" "$b"
	;;
esac

case "$#" in
0|1)
	echo "$USAGE" >&2
	exit 1
	;;
esac

case "$debug" in y*) set -x ;; esac

# the original tree.
src=$1

shift

for root
do
	from=$sym/
	[ "$src" != "$sym" ] && from=$src/

	if [ "$src" != "$sym" -a ! -d "$dest$root" ] ; then 
		mkdir "$dest$root" || exit
		# check for absolute or relative src.
		case "$src" in /*) pwd= ;; *) pwd="`pwd`/" ;; esac
		ln -s "$pwd$src/`basename "$root"`" "$dest$root"/$sym
	fi

	$note "${root}: directories"
	find "$from$root" -type d -a ! $skip -print |
		sed "s,^$from,," |
		while read d
		do
			$note $nonl " _ $dest$d "$nlc
			[ -d "$dest$d"/$sym ] && $note "" && continue
			[ -d "$dest$d" ] || mkdir "$dest$d" || exit
			ln -s ../$sym/"`basename "$d"`" "$dest$d"/$sym || exit
			$note "
 + "
		done

	cn=0
	$note "${root}: links"
	( find "$from$root" -type d -a $skip -print ;
	  find "$from$root" $skip -prune -o ! -type d -print ) |
		sed "s,^$from,," |  
		while read f
		do
			cn=`expr $cn + 1`
			[ $cn -ge 72 ] && cn=1 && $note ""
			[ $cn -eq 1 ] && $note $nonl " "$nlc
			$note $nonl "."$nlc
			[ -f "$dest$f" -o -h "$dest$f" ] && continue
			d="`dirname "$f"`"
			b="`basename "$f"`"
			ln -s "$sym/$b" "$dest$f" || exit
			$note $nonl "+"$nlc
		done
	$note " done."

	if [ -n "$copies" ] ; then
		cn=0
		$note $nonl "${root}: copies "$nlc
		find "$from$root" $copies -print |
			sed "s,^$from,," |  
			while read f
			do
				cn=`expr $cn + 1`
				[ $cn -ge 72 ] && cn=1 && $note ""
				[ $cn -eq 1 ] && $note $nonl " "$nlc
				$note $nonl "."$nlc
				[ -f "$dest$f" -o -h "$dest$f" ] && continue
				d="`dirname "$f"`"
				b="`basename "$f"`"
				cp -p "$d/$sym/$b" "$dest$f" || exit
				$note $nonl "+"$nlc
			done
		$note " done."
	fi
done