tl;dr, a safe way to program, for script, by adding these lines of code at the top of bash scripts for reliability.

#!/bin/bash
set -euo pipefail
IFS=$'\n\t'

set

A builtin that changes shell options. See manual.

• set +e disables option e, set -e enables
• set -e causes bash to exit if any command has a non-zero exit status
  • makes silent errors exit loudly, if last cmd of script succeeds, then script exits with 0, potentially hiding errors
• set -u exits bash if a variable that does not exist is referenced

• set -o pipefail makes exit code of pipelines that of a failing command instead of last command:

  $ grep some-string /non/existent/file | sort
  grep: /non/existent/file: No such file or directory # grep returns exit 2, sort has nothing to sort, returns exit 0
  $ echo $?
  0

IFS

The Internal Field Separator controls word splitting (or tokenization).

• When set to a string, each char in the string is considered by Bash to separate words
• changes how bash iterates through sequences
• kind of niche change, but makes iterating through lists more intuitive:
  ```bash
  names=(
  "Wayne Gretzky"
  "David Beckham"
  )

IFS='\n' # parse each line instead of each word
for name in ${names[@]}; do
echo $name
done

Wayne Gretzky

David Beckham

```

source