If condition help required

Shell Programming and Scripting
1

I have a if condition it checks its pid exist it means it is running, otherwise not running.

I am checking with ps


x=`ps -fu myuserid|grep java| |grep -v grep | awk '{print $2}'`

if [$x -eq 0 ]

then ............

Above code is giving integer error, because currently process of java is not running so its value is zero, so how i can i do that to check process exist then tell us process exist, otherwise tell us process not exist.

2

If should have space between brackets...
can reduce one grep
and avoid use of back tick's

try

x=$(ps -fu myuserid| grep -v grep | awk '/java/{print $2}')

if [ $x -eq 0 ]
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3 
x=$(ps -fu myuserid | grep [j]ava | awk '{print $2}')
if [ ! -z $x ]
then
  echo process is running
else
  echo process not running
fi
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4 
if [ $(ps -fu myuserid | grep -c [j]ava) -gt 0 ]
then    echo 'process is running'
else    echo 'process not running'
fi
2 Likes
5

Or:

ps -fu myuserid | grep [j]ava > /dev/null &&
  echo 'process is running' ||
    echo 'process not running'

if ps -fu myuserid | grep [j]ava > /dev/null; then
  echo 'process is running' 
else  
  echo 'process not running'
fi

If the grep implementation supports -q you can get rid of the > /dev/null part.
If pgrep is available (Linux/Solaris) you could substitute the above ps .. | grep .. pipeline with: pgrep -u myuserid -f [j]ava

1 Like