flock: bad number: myfile.lock

Question

I try to put a lock on a file like this:

flock -e myfile.lock

The result is:

flock: bad number: myfile.lock

Doesn't matter whether file exist or not, or whether I'm root. I even tried chmod a+rwx myfile. Still get the same error. I tried the same not on my machine but on Debian and I get the same error...

ceving · Accepted Answer · 2011-05-06T12:00:51.807

11

The command is missing. Try:

flock -e myfile.lock ls

The number is the file descriptor of the usage alternativ:

(
  flock -e 200
  ls
) 200>myfile.lock

See the man page.

edited May 06 '11 at 12:00

answered May 06 '11 at 11:55

ceving

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thanks, the number part I still dont get, but the missing command tip worked here: terminal 1 `flock -x ./test.txt sleep 10`, and after at terminal 2 `flock -x ./test.txt ls` – Aquarius Power Aug 18 '13 at 20:41
Why is the command `ls` necessary? – Viesturs May 09 '20 at 17:00
1

@Viesturs It is just a placeholder for anything you want to execute with the lock. – ceving May 12 '20 at 16:47

flock: bad number: myfile.lock

1 Answers1