Fix torify: Do not complain if we cannot find all socksifiers

No longer complain if we cannot find both torify and tsocks.  As long as
we have one we are happy.

Do not rely on which, it's not POSIX.

Catch error if torsocks fails and print an error message.

contrib/torify.in

@@ -3,57 +3,52 @@
 # Wrapper script for use of the tsocks(8) transparent socksification library
 # See the tsocks(1) and torify(1) manpages.
 
-# Copyright (c) 2004, 2006 Peter Palfrader
+# Copyright (c) 2004, 2006, 2009 Peter Palfrader
 # Modified by Jacob Appelbaum <jacob@appelbaum.net> April 16th 2006
 # May be distributed under the same terms as Tor itself
 
-
-# Define and ensure we have tsocks
-# XXX: what if we don't have which?
-TORSOCKS="`which torsocks`"
-TSOCKS="`which tsocks`"
-PROG=""
-if [ ! -x "$TSOCKS" ]
-then
-	echo "$0: Can't find tsocks in PATH. Perhaps you haven't installed it?" >&2
-else
-	PROG=$TSOCKS
-fi
-if [ ! -x "$TORSOCKS" ]
-then
-	echo "$0: Can't find torsocks in PATH. Perhaps you haven't installed it?" >&2
-else
-	PROG=$TORSOCKS
-fi
-
-if [ ! -x "$PROG" ]
-then
-	echo "$0: Can't find the required tor helpers in our PATH. Perhaps you haven't installed them?" >&2
-	exit 1;
-fi
+# taken from Debian's Developer's Reference, 6.4
+pathfind() {
+	OLDIFS="$IFS"
+	IFS=:
+	for p in $PATH; do
+		if [ -x "$p/$*" ]; then
+			IFS="$OLDIFS"
+			return 0
+		fi
+	done
+	IFS="$OLDIFS"
+	return 1
+}
 
 # Check for any argument list
-if [ "$#" = 0 ]
-then
+if [ "$#" = 0 ]; then
 	echo "Usage: $0 [-hv] <command> [<options>...]" >&2
 	exit 1
 fi
-if [ "$#" = 1 ] && ( [ "$1" = "-h" ] || [ "$1" = "--help" ] )
-then
+
+if [ "$#" = 1 ] && ( [ "$1" = "-h" ] || [ "$1" = "--help" ] ); then
 	echo "Usage: $0 [-hv] <command> [<options>...]"
 	exit 0
 fi
 
-if [ "$1" = "-v" ] || [ "$1" = "--verbose" ]
-then
-	echo "We're armed with the following tsocks: $TSOCKS"
-	echo "We're armed with the following torsocks: $TORSOCKS"
-	echo "We're attempting to use $PROG for all tor action."
+if [ "$1" = "-v" ] || [ "$1" = "--verbose" ]; then
+	verbose=1
 	shift 1
+else
+	verbose=0
 fi
 
-if [ "$PROG" = "$TSOCKS" ]
-then
+if pathfind torsocks; then
+	! [ "$verbose" -ge 1 ] || echo "Using torsocks as socksifier." >&2
+
+	exec torsocks "$@"
+	echo "$0: Failed to exec torsocks $@" >&2
+	exit 1
+
+elif pathfind tsocks; then
+	! [ "$verbose" -ge 1 ] || echo "Using tsocks as socksifier." >&2
+
 	# Define our tsocks config file
 	TSOCKS_CONF_FILE="/etc/tor/tor-tsocks.conf"
 	export TSOCKS_CONF_FILE
@@ -61,7 +56,7 @@ then
 	# Check that we've got a tsocks config file
 	if [ -r "$TSOCKS_CONF_FILE" ]
 	then
-		echo "WARNING: tsocks is known to leak DNS and UDP data." >&2
+		echo "WARNING: tsocks is known to leak DNS and UDP data.  If you had torsocks we would use that." >&2
 		exec tsocks "$@"
 		echo "$0: Failed to exec tsocks $@" >&2
 		exit 1
@@ -69,8 +64,8 @@ then
 		echo "$0: Missing tsocks configuration file \"$TSOCKS_CONF_FILE\"." >&2
 		exit 1
 	fi
-fi
-if [ "$PROG" = "$TORSOCKS" ]
-then
-	exec torsocks "$@"
+
+else
+	echo "$0: Can't find neither tsocks nor torsocks in your PATH. Perhaps you haven't installed either?" >&2
+	exit 1
 fi