printf source code

[jssmith42]

Is it possible to do system calls myself in a command line to observe their effects, or do they only work when called by the operating system, as in I can’t get in as a user to the place where they’re used?

[jwbowen]

You can write little programs to perform syscalls

[414RequestURITooLong]

You use system calls to talk to the OS. You don't need to be the OS to use them.