suse man page for shlock

Query: shlock

OS: suse

Section: 1

Format: Original Unix Latex Style Formatted with HTML and a Horizontal Scroll Bar

SHLOCK(1)						    InterNetNews Documentation							 SHLOCK(1)

NAME
shlock - Create lock files for use in shell scripts
SYNOPSIS
shlock [-b|-c|-u] -f name -p pid
DESCRIPTION
shlock tries to create a lock file named name and write the process ID pid into it. If the file already exists, shlock will read the process ID from the file and test to see whether the process is currently running. If the process exists, then the file will not be created. shlock exits with a zero status if it could create the lock file, or non-zero if the file refers to a currently active process.
OPTIONS
-b Process IDs are normally read and written in ASCII. If the -b flag is used, then they will be written as a binary int. -c If the -c flag is used, then shlock will not create a lock file, but will instead use the file to see if the lock is held by another program. If the lock is valid, the program will exit with a non-zero status; if the lock is not valid (i.e. invoking shlock without the flag would have succeeded), then the program will exit with a zero status. -f name name is the name of the lock file shlock attempts to create. If the file already exists, it will read the process ID from the file and exit with a non-zero status if this process is currently active. -p pid pid is the process ID to write into the file name. -u For compatibility with other systems, the -u flag is accepted as a synonym for -b since binary locks are used by many UUCP packages.
EXAMPLES
The following example shows how shlock would be used within a shell script: LOCK=<pathrun in inn.conf>/LOCK.send trap 'rm -f ${LOCK} ; exit 1' 1 2 3 15 if shlock -p $$ -f ${LOCK} ; then # Do appropriate work. else echo "Locked by `cat ${LOCK}`" fi
HISTORY
Written by Rich $alz <rsalz@uunet.uu.net> for InterNetNews after a description of HDB UUCP locking given by Peter Honeyman, and improved by Berend Reitsma to solve a race condition. Converted to POD by Julien Elie. $Id: shlock.pod 8357 2009-02-27 17:56:00Z iulius $ INN 2.5.2 2009-05-21 SHLOCK(1)
Related Man Pages
shlock(1) - redhat
nntpsend(8) - redhat
shlock(1) - suse
innxbatch(8) - suse
shlock(1) - osx
Similar Topics in the Unix Linux Community
Colloring Status of process or package
Working on Files
script to remove and recreate a lock file
If a string variable value exists in a set of values
Script to start process