diff -r 8bdfb1947cff -r bfe93d38998f util/tracediff
--- a/util/tracediff	Thu Feb 02 23:54:25 2012 -0800
+++ b/util/tracediff	Fri Feb 03 17:11:42 2012 +0000
@@ -70,19 +70,30 @@
 #
 # The '-n' argument to tracediff allows you to preview the two
 # generated command lines without running them.
-#
+# The '-p' argument to tracediff allows a different path for storing the
+# trace files.
 
 use FindBin;
+use File::Path;
 
 $dryrun = 0;
+$path = ".";
 
-if (@ARGV >= 1 && $ARGV[0] eq '-n') {
-    $dryrun = 1;
-    shift @ARGV;
-}
-
-if (@ARGV < 1) {
-    die "Usage: tracediff [-n] \"sim1|sim2\" [common-arg \"arg1|arg2\" ...]\n";
+if (@ARGV >= 1) {
+    while ($ARGV[0] eq '-n'|| $ARGV[0] eq '-p') {
+	# check for '-n' option
+	if ($ARGV[0] eq '-n') {
+	    $dryrun = 1;
+	    shift @ARGV;
+	}
+	# check for '-p' option
+	if ($ARGV[0] eq '-p') {
+	    shift @ARGV;
+	    $path = shift @ARGV;
+	}
+    }
+} else {
+    die "Usage: tracediff [-n][-p] \"sim1|sim2\" [common-arg \"arg1|arg2\" ...]\n";
 }
 
 foreach $arg (@ARGV) {
@@ -136,11 +147,11 @@
 # files (particularly config.py and config.ini) don't conflict.
 $dir1 = "tracediff-$$-1";
 $dir2 = "tracediff-$$-2";
-mkdir($dir1) or die "Can't create dir $dir1\n";
-mkdir($dir2) or die "Can't create dir $dir2\n";
+mkpath("$path/$dir1") or die "Can't create dir $path/$dir1\n";
+mkpath("$path/$dir2") or die "Can't create dir $path/$dir2\n";
 
-$cmd1 = "$sim1 -d $dir1 $args1 2>&1 |";
-$cmd2 = "$sim2 -d $dir2 $args2 2>&1 |";
+$cmd1 = "$sim1 -d $path/$dir1 $args1 2>&1 |";
+$cmd2 = "$sim2 -d $path/$dir2 $args2 2>&1 |";
 
 # Expect that rundiff is in the same dir as the tracediff script.
 # FindBin figures that out for us.
@@ -148,6 +159,3 @@
 
 print "Executing $fullcmd\n";
 system($fullcmd);
-
-
-