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This suggested edit was approved and applied to the post over 1 year ago by tripleeeā€­.

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  • The simple and obvious solution:
  • ```
  • sed 's/^ *//;s/ *$//'
  • ```
  • Many recipes you find online will erroneously add a `g` flag, but these regular expressions can only match once per line anyway.
  • (In some more detail, `s/from/to/g` says to replace all occurrences of `from` _on the current input line;_ but of course, if you know `from` can only match once, you don't want or need that.)
  • Your requirement to treat the first and last lines differently seems odd to me, but `sed` easily allows you to do that too.
  • ```
  • sed `1s/^ *//;$s/ *//'
  • ```
  • This adds the address expression `1` to the first command (which matches on line number 1) and the address `$` to the last (which matches the final input line).
  • Something similar could be achieved with Awk with a clever `RS` (record separator) but I'd consider that more obscure, as well as probably slower.
  • The simple and obvious solution:
  • ```
  • sed 's/^ *//;s/ *$//'
  • ```
  • Many recipes you find online will erroneously add a `g` flag, but these regular expressions can only match once per line anyway.
  • (In some more detail, `s/from/to/g` says to replace all occurrences of `from` _on the current input line;_ but of course, if you know `from` can only match once, you don't want or need that.)
  • Your requirement to treat the first and last lines differently seems odd to me, but `sed` easily allows you to do that too.
  • ```
  • sed `1s/^ *//;$s/ *$//'
  • ```
  • This adds the address expression `1` to the first command (which matches on line number 1) and the address `$` to the last (which matches the final input line).
  • Something similar could be achieved with Awk with a clever `RS` (record separator) but I'd consider that more obscure, as well as probably slower.

Suggested over 1 year ago by maukeā€­