Pid

mirusnet · #1 (**permalink**) 02-20-2008

How can I put the process id of ,for example, the following script to the pid file? Maybe $$ must be defined in some place?

Code:

daemon(){
        while true;
        do
                if [ -r "${FILE}" ]
                then
                        echo "`date +"%H:%M:%S"`" >> $FILE
                        sleep 3;
                fi
        done
}
daemon >/dev/null 2>&1 &

jim mcnamara · #2 (**permalink**) 02-20-2008

FYI: $$ is the pid of the current process, so:

Code:

echo "`date +"%H:%M:%S"` $$" >> $FILE

does write the pid to $FILE, but it is a child process because the & runs the function in the background.

Lukeadams · #3 (**permalink**) 02-20-2008

Good point... You may be able to 'source' the command by prepending a period[SPACE] so it runs in the same process/shell.

Untested but worth a shot:

Code:

. echo "`date +"%H:%M:%S"` $$" >> $FILE

jim mcnamara · #4 (**permalink**) 02-20-2008

I think the "daemon" is meant to run by itself in a child process. It doesn't do much.
Maybe they use to track usage of the script that runs it...

mirusnet · #5 (**permalink**) 02-20-2008

This example script works perfect only in following configuration:

Code:

daemon(){
        echo $$ > ${PF}
        while true; 
        do 
                if [ -r "${FILE}" ]
                then 
                        echo "`date +"%H:%M:%S"`" >> $FILE
                        sleep 3;
                fi
        done
}

#MAIN
case $1 in
        -daemon)
                daemon
                ;;
        *)
                $0 -daemon &
                ;;
esac
exit 0

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search
Display Modes	Rate This Thread
Switch to Linear Mode Hybrid Mode Switch to Threaded Mode	Rate This Thread:


	Powered by