2015-10-08 15:15:08 +00:00
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.Dd 2015-10-08
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2015-10-07 09:16:18 +00:00
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.Dt FLOCK 1
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.Os sbase
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.Sh NAME
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.Nm flock
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.Nd tool to manage locks on files
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.Sh SYNOPSIS
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.Nm
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2015-10-08 15:43:09 +00:00
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.Op Fl nosux
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2015-10-07 09:16:18 +00:00
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.Ar file
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.Ar cmd Op arg ...
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.Sh DESCRIPTION
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.Nm
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is used to manage advisory locks on open files. It is commonly used to prevent
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long running cron jobs from running in parallel. If
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.Ar file
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does not exist, it will be created.
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.Sh OPTIONS
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.Bl -tag -width Ds
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.It Fl n
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Set non-blocking mode on the lock. Fail immediately if the lock
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cannot be acquired.
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2015-10-08 15:43:09 +00:00
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.It Fl o
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Close the file descriptor before exec to avoid having the exec'ed
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program holding on to the lock.
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2015-10-07 09:16:18 +00:00
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.It Fl s
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Acquire a shared lock.
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.It Fl u
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Release the lock.
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.It Fl x
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Acquire an exclusive lock. This is the default.
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.El
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