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. cd /sys/lib/dist lock scan.lock replica/scan $dist/sources.replica

SOURCE

	/sys/src/cmd/lock.c

SEE ALSO

	intro(5), stat(5)