PID increments automatically - daemon

Question

I'm writing a init-script for a microservice and have the problem, that the PID of the process, that the program gives out (via echo) is not the process ID the process is having. The code:
#!/bin/bash
### BEGIN INIT INFO
# Provides: temp
# Description: temp
# required-start: $local_fs $remote_fs $network $syslog
# required-stop: $local_fs $remote_fs $network $syslog
# default-start: 3 5
# default-stop: 0 1 2 6
# chkconfig: 35 99 1
# description: Microservice init-script
### END INIT INFO
START_SCRIPT=${applicationDirectory}/script/start.sh
STOP_SCRIPT=${applicationDirectory}/script/stop.sh
PID_FILE=${runDirectory}/${microserviceName}_${environment}_${servicePort}
# ***********************************************
# ***********************************************
DAEMON=$START_SCRIPT
# colors
red='\e[0;31m'
green='\e[0;32m'
yellow='\e[0;33m'
reset='\e[0m'
echoRed() { echo -e "${red}$1${reset}"; }
echoGreen() { echo -e "${green}$1${reset}"; }
echoYellow() { echo -e "${yellow}$1${reset}"; }
start() {
#PID=`bash ${START_SCRIPT} > /dev/null 2>&1 & echo $!`
PID=`$DAEMON $ARGS > /dev/null 2>&1 & echo $!`
}
stop() {
STOP_SCRIPT $1
}
case "$1" in
start)
if [ -f $PID_FILE ]; then
PID=`cat $PID_FILE`
if [ -z "`echo kill -0 ${PID}`" ]; then
echoYellow "Microservice is already running [$PID]."
exit 1
else
rm -f $PID_FILE
fi
fi
start
if [ -z $PID ]; then
echoRed "Failed starting microservice."
exit 3
else
echo $PID > $PID_FILE
echoGreen "Microservice successfully started [$PID]."
exit 0
fi
;;
status)
if [ -f $PID_FILE ]; then
PID=`cat $PID_FILE`
if [ ! -z "`echo kill -0 ${PID}`" ]; then
echoRed "Microservice is not running (process dead but pidfile exists)."
exit 1
else
echoGreen "Microservice is running [$PID]."
exit 0
fi
else
echoRed "Microservice is not running."
exit 3
fi
;;
stop)
if [ -f $PID_FILE ]; then
PID=`cat $PID_FILE`
if [ ! -z "`echo kill -0 ${PID}`" ]; then
echoRed "Microservice is not running (process dead but pidfile exists)."
exit 1
else
PID=`cat $PID_FILE`
stop $PID
echoGreen "Microservice successfully stopped [$PID]."
rm -f $PID_FILE
exit 0
fi
else
echoRed "Microservice is not running (pid not found)."
exit 3
fi
;;
*)
echo "Usage: $0 {status|start|stop}"
exit 1
esac
Now, the program gives for example 2505 as PID. But when I use
ps aux | grep trans | grep -v grep
It outputs a number, that is the previously outputted number +1.
Can anyone give a guess? Any help is appreciated!

Answer 1

Your PID variable gets the pid of the shell that executes start.sh. The actual program executed by the script gets a different pid.