'\" t
.\"     Title: lckdo
.\"    Author: Michael Tokarev
.\" Generator: DocBook XSL Stylesheets vsnapshot <http://docbook.sf.net/>
.\"      Date: 2007-08-15
.\"    Manual: moreutils
.\"    Source: moreutils
.\"  Language: English
.\"
.TH "LCKDO" "1" "2007\-08\-15" "moreutils" "moreutils"
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.SH "NAME"
lckdo \- run a program with a lock held
.SH "SYNOPSIS"
.HP \w'\fBlckdo\fR\ 'u
\fBlckdo\fR [options] {lockfile} {program} [arguments]
.SH "DESCRIPTION"
.PP
\fBlckdo\fR
runs a program with a lock held, in order to prevent multiple processes from running in parallel\&. Use just like
\fBnice\fR
or
\fBnohup\fR\&.
.PP
Now that util\-linux contains a similar command named
\fBflock\fR, lckdo is deprecated, and will be removed from some future version of moreutils\&.
.SH "OPTIONS"
.PP
\fB\-w\fR
.RS 4
If the lock is already held by another process, wait for it to complete instead of failing immediately\&.
.RE
.PP
\fB\-W {sec}\fR
.RS 4
The same as \-w but wait not more than sec seconds\&.
.RE
.PP
\fB\-e\fR
.RS 4
Execute the program directly without forking and waiting (keeps an extra file descriptor open)\&.
.RE
.PP
\fB\-E {nnn}\fR
.RS 4
Set the file descriptor number to keep open when exec()ing (implies \-e)\&.
.RE
.PP
\fB\-n\fR
.RS 4
Do not create the lock file if it does not exist\&.
.RE
.PP
\fB\-q\fR
.RS 4
Produce no output if lock is already held\&.
.RE
.PP
\fB\-s\fR
.RS 4
Lock in shared (read) mode\&.
.RE
.PP
\fB\-x\fR
.RS 4
Lock in exclusive (write) mode (default)\&.
.RE
.PP
\fB\-t\fR
.RS 4
Test for lock existence\&.
.RE
.SH "EXIT STATUS"
.PP
If the lock was successfully acquired, the return value is that of the program invoked by
\fBlckdo\fR\&. If the lock couldn\*(Aqt be acquired, EX_TEMPFAIL is returned\&. If there was a problem opening/creating or locking the lock file, EX_CANTCREAT or EX_OSERR will be returned\&.
.SH "AUTHOR"
.PP
Michael Tokarev