Adds the ifs package

ifs.sh

+#
+# LECA Bash library
+#
+# The LECA bash library provides a set of function used for helping
+# development of bash script mainly to write job script on the luke
+# cluster
+#
+# The files from the LECA Bash library must be sourced from your main script
+#
+
+include stack
+
+newstack LECABASH_IFS_STACK
+
+function pushifs() {
+	if [[ -z "${IFS}" ]]; then
+		pushvalue LECABASH_IFS_STACK "@@NULL@@"
+	else
+		local v=$(echo -n "$IFS" | od -b | head -n +1 | sed 's/[0-9]* //' | sed 's/ /\\/g' | sed 's/^/\\/')
+		pushvalue LECABASH_IFS_STACK "$v"
+	fi
+	
+	if [[ -z "$1" ]]; then
+		unset IFS
+	else
+		IFS="${1}"
+	fi
+
+}
+
+function popifs() {
+
+	local v
+	v=$(popvalue LECABASH_IFS_STACK v)
+	
+	if [[ "$?"!="0" ]]; then
+		if [[ "$v"=="@@NULL@@" ]]; then
+			unset IFS
+		else
+			IFS=$(eval "echo -n \$'$x'")
+		fi
+	else
+		return 1
+	fi
+	
+	return 0
+	
+}
\ No newline at end of file