feat(user/bk-copy-rand-music):Optimize file processing

[BK-2020-03.git] / unitproc / bkt-yellDieMust

#!/bin/bash
# Desc: Defines bash functions yell(), die(), and must(), which are useful for
#   indicating where in a script an error occurs.
# Note: All three functions should be added together if used at all.
# Ref/Attrib: [1] Yell, Die, Try Three-Fingered Claw technique https://stackoverflow.com/a/25515370
# Depends: GNU Coreutils 8.30
# Version 1.0.0

#==BEGIN Define script parameters==
#==END Define script parameters==

#===BEGIN Declare local script functions===
yell() { echo "$0: $*" >&2; } # print script path and all args to stderr
die() { yell "$*"; exit 111; } # same as yell() but non-zero exit status
must() { "$@" || die "cannot $*"; } # runs args as command, reports args if command fails
#===END Declare local script functions===

#==BEGIN sample code==
yell "This message should appear in stderr.";
must echo "This message should appear in stdout.";
must eeeecho "This message should appear in an error message in stderr.";
yell "This message should not appear because \"must eeeecho\" failed.";
#==END sample code==