Useful bash flags for scripts verbose trace expand error exit

Useful flags:
set -v # "verbose" - echo commands

set -x # "xtrace" - like verbose but expands commands

set -e # "errexit" - abort script at first error

set -u # "nounset" - strict mode: undefined variable causes an exit

Long format:

set -o verbose

Bash "strict mode":
#!/bin/bash
set -euo pipefail
IFS=$'\n\t'

(source, source)