How to check if pkill was successful

We use pkill to check if a program is running to kill it before restarting it when new code is being deployed.

pkill --signal 15 --pidfile programname.pid

This normally works, but when there is a problem and the application program hangs, signal 15 doesn't kill the process. The exit codes for pkill are:

EXIT STATUS
       0      One or more processes matched the criteria.
       1      No processes matched.
       2      Syntax error in the command line.
       3      Fatal error: out of memory etc.

For obvious reasons to me after thinking about it, it cannot return a code to indicate that the process kill was successful, since pkill only sends a signal to it and nothing more. So I will have to check if the process was ended and if not try again with signal 9 and if not killed yet, try with signal 6 (or some others even).

So I guess doing some kind of if/elif/else/fi to test for this should suffice:

#!/bin/bash
pkill --signal 15 --pidfile programname.pid
result1=$?
echo 'result1 is ' $result1
if [ "$result1" -eq 0 ]  
then
    echo "programname found running"
    pgrep --pidfile programname.pid
    result2=$?
    if [ "$result2" -eq 1 ]
    then
        # happens if pid# is not found
        echo "programname killed successfully with signal 15"
        # restart the program that was killed
    else
        pkill --signal 9 --pidfile programname.pid
        result3=$?
        if [ "result3" -eq 0 ]
        then
            pgrep --pidfile programname.pid
            result4=$?
            if [ "result4" -eq 1 ]
            then
                echo "programname killed successfully with signal 9"
                # restart the pgram that was killed
            fi
        fi
    fi
elif [ $result1 -eq 1 ]
then
    echo "programname pid# not found. Is the system running?"
else
    echo "pkill exited with error" $result1
fi

echo 'Continue...'

This all seems a bit convoluted, or am I just being pedantic? Is there a better way to achieve this result in a script?

I decided that creating a function to do this is the better option. Also, using a for loop seems to be a neater solution:

#!/bin/bash
trykill () {

    timeout=${2:-5} 
    # echo "wait =" $timeout

    # Run the loop for signal 15, 9 and 6
    for n in 15 9 6;
    do
        if [[ -f "$1.pid" ]]; then
            pkill --signal $n --pidfile $1.pid  
            result1=$?
        else
            result1=1
        fi
        #echo 'result1 is ' $result1
        if [ "$result1" -eq 0 ]  
        then
            echo $1 "found running, waiting" $timeout "seconds for process to die."
            sleep $timeout  # Wait # seconds set by second parameter
            pgrep --pidfile $1.pid
            result2=$?
            if [ "$result2" -eq 1 ]
            then
                 # happens if pid# is not found
                echo $1 "killed successfully with signal" $n"."
                return 0
            fi
        elif [ $result1 -eq 1 ]
        then
            echo $1".pid # not found." $1 "doesn't seem to be running. Starting it anyway."
            return 0
        else
            echo "pkill exited with error" $result1
            return 1
        fi
    done
}

And I call the function for each service I want to restart. Here's a example script to do that.

#!/bin/bash
source trykill.sh

trykill $1
result1=$?
#echo 'result1 is ' $result1
if [ "$result1" -eq 0 ]  
then
    echo 'Start' $1 'again'
fi

echo 'Done.'