62 lines
925 B
Text
62 lines
925 B
Text
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.TH LOCK 1
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.SH NAME
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lock \- run a command under lock
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.SH SYNOPSIS
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.B lock
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[
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.B -w
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]
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.I lockfile
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[
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.I command
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[
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.I argument
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\&...
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] ]
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.SH DESCRIPTION
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.I Lock
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runs
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.I command
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(default
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.LR rc )
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with
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.I arguments
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while holding
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.I lockfile
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open and (over)writing at least one byte each minute
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to keep the exclusive-access lock alive.
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If
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.I lockfile
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doesn't already have the exclusive-access bit set in
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its mode,
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the exclusive-access bits are set in its mode and
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.BR qid.type .
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.PP
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Under
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.BR -w ,
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.I lock
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waits for exclusive access to
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.I lockfile
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instead of just trying once.
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.PP
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.I Lock
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sets
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.B /env/prompt
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to contain the name of the lock file.
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.SH EXAMPLES
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Build a
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.IR replica (1)
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database while preventing collisions with other occurrences.
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.IP
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.EX
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cd /sys/lib/dist
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lock scan.lock replica/scan $dist/sources.replica
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.EE
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.SH SOURCE
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.B /sys/src/cmd/lock.c
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.SH SEE ALSO
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.IR intro (5),
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.IR stat (5)
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.\" .SH DIAGNOSTICS
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.\" .SH BUGS
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