# applies any patches providing in the grading directory,
# and installs a default pintos/src/constants.h
sub extract_sources {
- # Nothing to do if we already have a source tree.
- return if -d "pintos";
-
+ # Make sure the output dir exists.
-d ("output") || mkdir ("output") or die "output: mkdir: $!\n";
+ # Nothing else to do if we already have a source tree.
+ return if -d "pintos";
+
my ($tarball) = choose_tarball ();
# Extract sources.