coproc is a shell keyword related to coprocesses in GNU Bash

ABOUT coproc Bash 4.0 introduced coprocesses, a feature certainly familiar to ksh users. The coproc keyword starts a command as a background job, setting up pipes connected to both its stdin and stdout so that you can interact with it bidirectionally. Optionally, the co-process can have a name NAME. If NAME is given, the command …

struct keyword and getopt_long

The getopt() function parses the command-line arguments. Its arguments argc and argv are the argument count and array as passed to the main() function on program invocation. An element of argv that starts with ‘-‘ (and is not exactly “-” or “–“) is an option element. The characters of this element (aside from the initial …