bash script to check running process

Question

I wrote a bash-script to check if a process is running. It doesn't work since the ps command always returns exit code 1. When I run the ps command from the command-line, the $? is correctly set, but within the script it is always 1. Any idea?

#!/bin/bash
SERVICE=$1

ps -a | grep -v grep | grep $1 > /dev/null
result=$?
echo "exit code: ${result}"
if [ "${result}" -eq "0" ] ; then
    echo "`date`: $SERVICE service running, everything is fine"
else
    echo "`date`: $SERVICE is not running"
fi

Bash version: GNU bash, version 3.2.25(1)-release (x86_64-redhat-linux-gnu)

Answer 1

Could you just check to see if you get non-empty output from the grep command instead of relying on return values?

Answer 2

Tried your version on BASH version 3.2.29, worked fine. However, you could do something like the above suggested, an example here:

#!/bin/sh

SERVICE="$1"
RESULT=`ps -a | sed -n /${SERVICE}/p`

if [ "${RESULT:-null}" = null ]; then
    echo "not running"
else
    echo "running"
fi

Answer 3

I found the problem. ps -ae instead ps -a works.

I guess it has to do with my rights in the shared hosting environment. There's apparently a difference between executing "ps -a" from the command line and executing it from within a bash-script.

Answer 4

Working one.

Made by www.activnet.info

!/bin/bash

CHECK=$0 SERVICE=$1 DATE=date OUTPUT=$(ps aux | grep -v grep | grep -v $CHECK |grep $1) echo $OUTPUT if [ "${#OUTPUT}" -gt 0 ] ; then echo "$DATE: $SERVICE service running, everything is fine" else echo "$DATE: $SERVICE is not running" fi