May 26, 2018
UNIX/POSIX shell helper for running pipes safely
pipestatus - source file for POSIX shell that allows to obtain an exit status of every program in a pipe.
When we program in shell we often run pipes like this
prog1 args1 | prog2 args2 | ... | progN argsN
POSIX says that exit status of pipe is the exit status of LAST program in it, i.e. progN in our example. That is, exit status of all other programs in pipe is silently ignored. But in many situations exit status of all programs in pipe should be checked to make program robust. Some shells like BASH and ZSH have special extensions for doing this but POSIX shell unfortunately doesn’t provide an EASY way for doing this.
In order to solve the problem, described above pipestatus was written.