flock

Простая защита от двойного запуска заданий cron

• -s –shared Get a shared lock
• -x –exclusive Get an exclusive lock
• -u –unlock Remove a lock
• -n –nonblock Fail rather than wait
• -w –timeout Wait for a limited amount of time
• -o –close Close file descriptor before running command
• -c –command Run a single command string through the shell

* * * * * /usr/bin/flock --lockfile=/tmp/myapp.locked -- /path/to/myapp