Comment on Show HN: Linux CLI tool to provide mutex locks for long running bash opsparentComments−yjftsjthsd-h1yWhy (; flock -n 9 and not ( flock -n 9 ?−apopapo1yIt's a "for" loop.−marklgr1yCould you elaborate?−apopapo1yA 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 ...; )−yjftsjthsd-h1yIt 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)
Comments
Why
and notIt's a "for" loop.
Could you elaborate?
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 ...; )
It doesn't seem to work?
(This is bash)