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Inside [[ ]] I do not need to quote variables right?

Rather than

if [[ "$flrm" == *"org"* || "$flrm" == "all" ]]; then
  printf '%s\n' "Delete: $fl"
fi

I can do

if [[ $flrm == *"org"* || $flrm == "all" ]]; then
  printf '%s\n' "Delete: $fl"
fi
Vera
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    Does this answer your question? [When is double-quoting necessary?](https://unix.stackexchange.com/questions/68694/when-is-double-quoting-necessary). See in particular the section "Where you can omit the double quotes" of @Gilles' answer. – AdminBee Oct 21 '21 at 07:48
  • It says that within double brackets (which are shell special syntax) quoting is not required, except where a pattern or regular expression is expected on the right-hand side of `=`, `==`, `!=`, or `=~`. – Vera Oct 21 '21 at 07:54
  • This would mean that `[[` prevents word splitting of variable values, contrary to `[`'. – Vera Oct 21 '21 at 08:02
  • With single brackets `[ ]`, I have seen people using `if [ $var = "test" ]` and `if [ $var == "test" ]`. I do not think there is a difference, or am I wrong? – Vera Oct 21 '21 at 08:08
  • @AdminBee All shells that support `[[ … ]]` support both `=` and `==`, so neither it more correct than the other. Ksh documents `=` as deprecated. Mksh documents `==` as deprecated. Bash and zsh recommend them equally (when inside double brackets). However, inside single brackets or after `test`, `=` is preferable because most shells that _don't_ support double brackets, and standalone `test` implementations, only recognize `=`. – Gilles 'SO- stop being evil' Oct 21 '21 at 09:09

0 Answers0