ids-functions.pl: Add function to create empty files

This generic function can be used to create any kind of emtpy files -
it just requires the full path and filename to work.

If the specified file exists at calltime, the function will abort
to prevent from overwriting existing files and content.

Signed-off-by: Stefan Schantl <stefan.schantl@ipfire.org>

config/cfgroot/ids-functions.pl

@@ -355,4 +355,26 @@ sub call_suricatactrl ($) {
 	return;
 }
 
+#
+## Function to create a new empty file.
+#
+sub create_empty_file($) {
+	my ($file) = @_;
+
+	# Check if the given file exists.
+	if(-e $file) {
+		# Do nothing to prevent from overwriting existing files.
+		return;
+	}
+
+	# Open the file for writing.
+	open(FILE, ">$file") or die "Could not write to $file. $!\n";
+
+	# Close file handle.
+	close(FILE);
+
+	# Return true.
+	return 1;
+}
+
 1;