| .Dd 2015-10-08 |
| .Dt FLOCK 1 |
| .Os sbase |
| .Sh NAME |
| .Nm flock |
| .Nd tool to manage locks on files |
| .Sh SYNOPSIS |
| .Nm |
| .Op Fl nosux |
| .Ar file |
| .Ar cmd Op arg ... |
| .Sh DESCRIPTION |
| .Nm |
| is used to manage advisory locks on open files. It is commonly used to prevent |
| long running cron jobs from running in parallel. If |
| .Ar file |
| does not exist, it will be created. |
| .Sh OPTIONS |
| .Bl -tag -width Ds |
| .It Fl n |
| Set non-blocking mode on the lock. Fail immediately if the lock |
| cannot be acquired. |
| .It Fl o |
| Close the file descriptor before exec to avoid having the exec'ed |
| program holding on to the lock. |
| .It Fl s |
| Acquire a shared lock. |
| .It Fl u |
| Release the lock. |
| .It Fl x |
| Acquire an exclusive lock. This is the default. |
| .El |