# works
system("java -jar ~/src/Project-X_0.91.0/ProjectX.jar -demux");

# doesn't work
system(qw#java -jar ~/src/Project-X_0.91.0/ProjectX.jar -demux#);

# doesn't work
open($fh, '-|', qw#java -jar ~/src/Project-X_0.91.0/ProjectX.jar -demux#);

print while (<$fh>);

close $fh;