zcsleep is a program that, like sleep(1), takes a duration on the command line, then quietly waits for that amount of time before exiting. It is unlike sleep(1) in that:

• One can specify a particular system clock to use for sleeping: CLOCK_REALTIME, CLOCK_MONOTONIC, etc. This can be useful in the face of clock adjustments, system suspends, and the like.

• It is not as polished as sleep(1): as it stands (August 2020), the basic functionality works, and it should be robust against bad inputs, but the user interface (especially the error reporting) isn’t as friendly as it could be. (The code could use better documentation, too.)

As it stands, it’s good enough for my (Zachary Catlin) purposes, but may not be ready for general usage. If someone wants to run with this idea and turn it into a better utility, or just finds it useful as-is, go for it, but this is not supported by me.

It has been tested only on Linux, but should compile and run on recent POSIX-compliant systems with few or no changes.