How to check a process is already running of the Bash command line for Linux

How to check a process is already running of the Bash command line for Linux

if not running the start it

Example:

Shell Script 1:
#!/bin/sh

program=xxx #process name

sn=`ps -ef | grep $program | grep -v grep |awk 'print $2'` #get pid

if [ "$sn" = "" ] #if '',then not running

then

nohup /home/oracle/xxx & #running in the background

echo start!

else

echo running

fi

Shell Script 2:
#!/bin/sh

ps -ef |grep ./FileServer > /dev/null 2>&1 #write pid to /dev/null

if [ $? -eq 0 ] #0 is running

then

echo logprocess running!

else

nohup /home/oracle/xxx &

echo start!

fi

Shell Script 3:
#!/bin/sh

count=`ps -fe |grep "log.out" | grep -v "grep" | wc -l`

if [ $count -lt 1 ]; then

/root/sh/restart.sh

How to check a process is already running of the Bash command line for Linux