From www.purplecow.org

System call breakdown for ruby's "gem" command

Overview

Called with no parameters - the sole actual work is to print usage information. It takes a long time, so let's have a look at what happens:

A quick truss

$ truss gem >rubygem.truss 2>&1
$ grep -c open rubygem.truss
656
$ grep -c stat rubygem.truss
1372
$ wc -l rubygem.truss
    4836 rubygem.truss

Breakdown

Oh dear! So what is it actually doing?

• brk: 701
• close: 553
• stat: 1371
• llseek: 535
• read: 889
• open: 656
• write: 22 (That's actually printing the usage information)
• other: 234 (mainly mmap)

A graph