Show HN: Linux CLI tool to provide mutex locks for long running bash ops

Re:Show HN: Linux CLI tool to provide mutex locks for long r... by apopapo on Thursday July 17, 2025 @08:52AM (#44592802)

A for loop in a shell script may sometimes look like this:

`for ((i = 0 ; i < max ; i++ )); do echo "$i"; done`

Here this is essentially a "while" loop, meaning it will keep executing the commands as long as we don't reach `exit 1`.

(; flock -n 9 || exit 1; # ... commands executed under lock ...; )

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Re:Show HN: Linux CLI tool to provide mutex locks for long r... by yjftsjthsd-h on Friday July 18, 2025 @11:52PM (#44612441)

It doesn't seem to work?

  [~] 0 $ ( flock -n 9 || exit 1; echo in loop ; sleep 3 ; echo done working ; ) 9>~/tmp/mylock
  in loop
  done working
  [~] 0 $ (; flock -n 9 || exit 1; echo in loop ; sleep 3 ; echo done working ; ) 9>~/tmp/mylock
  -bash: syntax error near unexpected token `;'
  [~] 2 $

(This is bash)

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