Example commands

You probably don't want to deploy any of this.

The hello.c and skeleton.c commands provide templates for new commands:
hello.c is clean and simple, skeleton.c demonstrates the option parsing
infrastructure and having multiple commands per file. When writing a new
command, copying hello.c or skeleton.c to the new name may provide a good
starting point. (The minimal staring point is toys/posix/false.c)

The demo_* commands demonstrate infrastructure, and do regression testing.

Other commands in here are obsolete versions still in some recent Linux systems
(and often still in posix), but not really useful on modern systems.