Know when a particular application is running

Shell Programming and Scripting
1

Is it possible in unix to write a script that could determine when a particular application is running or not ?

2

There are several ways. It would be useful in the future if you mentioned your OS.
here are two ways:

#On systems with pgrep - like Solaris Linux
is_running() 
{
   pgrep $1
}
# almost any system
is_running()
{
   ps -ef | grep "$1"  | grep -v "grep"
}

usage

is_up=$(is_running myppname)
if [[ -z "$is_up" ]] ; then
    echo "myappname is not running"
else
    echo "myappname is running"
fi
3

Thanks Jim

Its an old version of HP unix, I'll give your second iteration a try.

4

In addition to Jim's suggestion, you could kill the output inside the function and then I think it looks nicer when you use it:

is_running()
{
   pgrep "$1" >dev/null 2>&1
}

or

is_running()
{
   ps -ef | grep "$1" | grep -qv grep
}

Then you can do this:

if is_running myppname
then
    echo "myappname is not running"
else
    echo "myappname is running"
fi