Useful Bash code, with no particular order

At the top of the file, always start your scripts with:

set -euo pipefail

• -e: The -e option will cause a bash script to exit immediately when a command fails.
• -o pipefail: This particular option sets the exit code of a pipeline to that of the rightmost command to exit with a non-zero status, or to zero if all commands of the pipeline exit successfully.
• -u: This option causes the bash shell to treat unset variables as an error and exit immediately.