Programming

consider the given prg.

main() {
.....

function1(); /* to write into a file or log */

printf(" ");
.....
}

when the control reaches function1(), it should get executed in the
background.At the same time main's printf(" ") statement should also get executed.i.e function1() should be independent of the main after it is called.Both should run simultaneously.


Also the background process should not return to main and handle other requests in background (e.g waiting for the msg Q to get filled up).

fork within the program to create a child process and execute the function1 inside the child process
and printf would resume with the parent process

Code:

pid=fork();
if( pid == 0 ) //child
{
function1();
}
else if( pid > 0 ) //parent
{
printf("");
}

you need to control regarding which should run first parent or child.

thanks matrixmadhan, but while using fork, it will return to the main.
we want it to run in the background handling requests(writing to file whenever
messge Q is full)

user seperate Threads for each operation.

ok bankpro, fork is just a diversion from the main program. now you dont want it to return to main, then you do one thing, put the function part as a different program. and instead of calling the function, call "exec" function with the program name containing your function as the argument.
and since you want to make it run in background, you have to make the new program called in child using fork, as a daemon program.
I am sure you will find code snippets for a daemon program on the forum, if you do a search, if not check out this link
http://www.geocities.com/hemantborole/
click on KnowledgeBank, on the next page, click on C under My Programs, and in the list of programs, click on daemon.c to see the sample of the daemon process.

Hello Linuxpenguin


ur logic helped us to solve our issue.

thanks 4 ur help