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Full Discussion: Creating Multiple Processes
Top Forums Programming Creating Multiple Processes Post 302392519 by Vikings1201 on Thursday 4th of February 2010 04:12:21 PM
Old 02-04-2010
Creating Multiple Processes

I am having problems creating multiple forks. I want create a certain number of forks, each call a program and each wait for a different value. How is this accomplished my loop is not doing the trick.

Code:
for (i = 0; i < 5; i++) {

        if (fork() < 0) {
            //print error
        }

        else if (fork() == 0) {
            //run a program (exec(...)
        }

        else {
            p_id = wait(&result);
        }
    }

I know how to use the wait() and exec() call but can't figure out how to do this for multiple forks I need each fork to return a differnt value.

Any help much appreciated.
 

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FORK(2) 							System Calls Manual							   FORK(2)

NAME
fork - spawn new process SYNOPSIS
fork( ) DESCRIPTION
Fork is the only way new processes are created. The new process's core image is a copy of that of the caller of fork. The only distinc- tion is the fact that the value returned in the old (parent) process contains the process ID of the new (child) process, while the value returned in the child is 0. Process ID's range from 1 to 30,000. This process ID is used by wait(2). Files open before the fork are shared, and have a common read-write pointer. In particular, this is the way that standard input and output files are passed and also how pipes are set up. SEE ALSO
wait(2), exec(2) DIAGNOSTICS
Returns -1 and fails to create a process if: there is inadequate swap space, the user is not super-user and has too many processes, or the system's process table is full. Only the super-user can take the last process-table slot. ASSEMBLER
(fork = 2.) sys fork (new process return) (old process return, new process ID in r0) The return locations in the old and new process differ by one word. The C-bit is set in the old process if a new process could not be cre- ated. FORK(2)
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