An external process cannot change a variable in your current process. So BREAK cannot get changed from anything in process or Tunnel.sh.
However, you can switch on the existence of a file, like this:
Code:
LOCK=/var/run/tunnel-keepalive.pid
echo $$ >LOCK
# start tunnel here
while [ -f $LOCK ]; do
# Test to see if tunnel is still up, if not: start again
sleep 5
done
Last edited by otheus; 02-04-2009 at 10:22 AM..
Reason: space between $$ >
Hi,
I was hoping someone would be able to help me out. I've got a Python script that I need to run 60 times concurrently (with the number added as an argument each time) via nightly cron. I figured that this would work:
30 1 * * * for i in $(seq 0 59); do $i \&; done
However, it seems to... (4 Replies)
In all of my brief and superficial experience with Unix or Linux, the one curious and consistent thing has been that 'cd ./' (back up one directory level) has done absolutely nothing in any of them. Now I understand that, at least for bash, 'cd ./' appears to have been substituted by 'cd ..'
Am... (1 Reply)
I'm working on a script (mostly for practice) to simplify a task I have to do every now and then. I have a cluster with 6 servers on it, each server has a directory with a set of files called *.pid and *.mpid. Each file contains the pid of a process that may or may not be running on that server.... (3 Replies)
Hi all,
I have one script. Its job is to get 1 file from dirA and 1 file from dirB as parameters for another python script.
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I'm reading about debugging aids in bash and have come across the set command. It says in my little book that an addition to typing
set
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I an using the below functions in my script.
---------
checkRT()
{
subHeader "Runtime Check"
for nn in `cat $HOST_FILE|egrep -i 'msdp|ca|backup|db'|grep -v '#'|sed '/^$/d'|awk '{ print $1":"$2":"$3}'`
do
fhba=`expr $nn|cut -d: -f2`
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subSubHeader $fhba2
ssh... (1 Reply)
Hi All,
I have a cron job set up which is set to run every 10 seconds.
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#!/bin/bash
function nu ()
{
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ssh host "$(typeset -f); nu"
... (9 Replies)
Hi ,
I am a total beginner so bear with me.
I have the below code which works . I need to extend it by iterating thru the array arr and executing a command in each loop. some thing on the lines of below.
I need to run this in a Jenkins script , so I would need below
bash script to run... (6 Replies)
Discussion started by: SVRao19056
6 Replies
LEARN ABOUT CENTOS
shlock
SHLOCK(1) General Commands Manual SHLOCK(1)NAME
shlock - create lock files for use in shell scripts
SYNOPSIS
shlock -p pid -f name [ -b ] [ -u ] [ -c ]
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 if the process is currently running. If the process exists, then the file will not be created.
Shlock exits with a zero status if it was able to create the lock file, or non-zero if the file refers to 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. For
compatibility with other systems, the ``-u'' flag is accepted as a synonym for ``-b'' since binary locks are used by many UUCP pack-
ages.
-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.
EXAMPLES
The following example shows how shlock would be used within a shell script:
LOCK=/var/run/innd/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> after a description of HDB UUCP locking given by Peter Honeyman. This is revision 1.9, dated
1996/10/29.
SHLOCK(1)