NAME     
| lock – run a command under lock | 
SYNOPSIS     
| lock [ –w ] lockfile [ command [ argument ... ] ] | 
DESCRIPTION     
| Lock runs command (default rc) with arguments while holding lockfile
    open and (over)writing at least one byte each minute to keep the
    exclusive–access lock alive. If lockfile doesn't already have the
    exclusive–access bit set in its mode, the exclusive–access bits
    are set in its mode and qid.type. Under –w, lock waits for exclusive access to lockfile instead of just trying once. 
    Lock sets /env/prompt to contain the name of the lock file. | 
EXAMPLES     
| Build a replica(1) database while preventing collisions with other
    occurrences. 
 | 
SOURCE     
| /sys/src/cmd/lock.c | 
SEE ALSO    
| intro(5), stat(5) |