Sponsored Content
Full Discussion: Parent,child wait,signal
Top Forums Programming Parent,child wait,signal Post 302528168 by Cuervo on Monday 6th of June 2011 02:39:25 PM
Old 06-06-2011
Parent,child wait,signal

Hello. I want to make a child do some stuff,wait,then the parent does some stuff and then child does some stuff and waits again.I have made the following but it does not work.Can anybody help me?
Code:
    pid1 = fork();
    if (pid1 == -1) 
    { 
        perror("Can't create child\n");
        exit(1);
    }
    else 
        if (pid1 == 0) 
        {
            ppid=getppid();
            sprintf(ppidstr,"%d", ppid);
            if(execl("myprogram.exe","myprogram.exe",ppidstr) == -1)
                fprintf(stderr,"execl Error!\n");
            wait(NULL);//Wait until the parent opens myfifo
           printf("I am back to do some more stuff");
           exit();
        }
        else 
            {
                waitpid(0,NULL,0);//wait for the child's signal
                int fd = open(myfifo, O_WRONLY);
                write(fd, "Hi", sizeof("Hi"));
                    close(fd);
                  waitpid(0,NULL,0);//wait for the child's signal
                printf("My child ended ");
                exit(1);
            }

 

10 More Discussions You Might Find Interesting

1. UNIX for Advanced & Expert Users

how to make a parent wait on a child shells running in background?

Hi I have a shell script A which calls another 10 shell scripts which run in background. How do i make the parent script wait for the child scripts complete, or in other words, i must be able to do a grep of parent script to find out if the child scripts are still running. My Code: ... (1 Reply)
Discussion started by: albertashish
1 Replies

2. Programming

How can I make the parent thread wait

Hi All, I will be glad if you could help me resolve this problem. I have created two detachable threads and wanted to them execute independent of the parent thread ( the main task which creates the detachable threads). But I see no output coming from the execution of two detachable threads.... (4 Replies)
Discussion started by: jayfriend
4 Replies

3. Shell Programming and Scripting

How to make the parent process to wait for the child process

Hi All, I have two ksh script. 1st script calls the 2nd script and the second script calls an 'C' program. I want 1st script to wait until the 'C' program completes. I cant able to get the process id for the 'C' program (child process) to make the 1st script to wait for the second... (7 Replies)
Discussion started by: sennidurai
7 Replies

4. UNIX for Dummies Questions & Answers

Sending signal from child to parent process!

Hi All, I facing a problem in handling signals between parent process communication. I am trying to send a signal(SIGINT) from child to parent. I am using kill function to do so and I am trying to read the signal using sigaction(). But the program is ending abruptly and I am not able to figure out... (4 Replies)
Discussion started by: vkn_1985
4 Replies

5. Programming

Parent process starts before the child using signal, in C

Hi, i want that the parent process start before the child, this code doesn't work, if the child start before the parent it wait for signal, then the father send the signal SIGALRM and the child catch it and call printf; else the father call printf and send the signal to the child that call its... (1 Reply)
Discussion started by: blob84
1 Replies

6. Homework & Coursework Questions

Need help with deleting childīs parent and child subprocess

1. The problem statement, all variables and given/known data: I need to make an program that in a loop creates one parent and five children with fork(). The problem i'm trying to solve is how to delete the parent and child of the childīs process. 2. Relevant commands, code, scripts,... (0 Replies)
Discussion started by: WhiteFace
0 Replies

7. Emergency UNIX and Linux Support

signal between parent process and child process

Hello, everyone. Here's a program: pid_t pid = fork(); if (0 == pid) // child process { execvp ...; } I send a signal (such as SIGINT) to the parent process, the child process receive the signal as well as the parent process. However I don't want to child process to receive the... (7 Replies)
Discussion started by: jackliang
7 Replies

8. Shell Programming and Scripting

forking a child process and kill its parent to show that child process has init() as its parent

Hi everyone i am very new to linux , working on bash shell. I am trying to solve the given problem 1. Create a process and then create children using fork 2. Check the Status of the application for successful running. 3. Kill all the process(threads) except parent and first child... (2 Replies)
Discussion started by: vizz_k
2 Replies

9. Shell Programming and Scripting

parent process needs to wait

I have two scripts lets say A.expect and B.sh needs to be executed. I am executing B.sh from A.expect where B.sh has sleep command. My problem is that when B.sh encounters the sleep command my A.expect starts executing and exits. but my A.expect should execute only after completing B.sh. Is... (3 Replies)
Discussion started by: priya@2012
3 Replies

10. Shell Programming and Scripting

How make parent to wait from child process?

Hi all, I am starting mgen5 for sometime depends on input from a file, in a child process. now I want to make parent to wait in this child process till mgen5 finishes, or timeout happens. could anyone please tell me how to make parent to wait in child process in shell script? thanks... (2 Replies)
Discussion started by: girijajoshi
2 Replies
wait.h(3HEAD)							      Headers							     wait.h(3HEAD)

NAME
wait.h, wait - wait status SYNOPSIS
#include <sys/wait.h> DESCRIPTION
When a process waits for status from its children using either the wait(3C) or waitpid(3C) function, the status returned can be evaluated with the following macros, defined in <sys/wait.h>. These macros evaluate to integral expressions. The stat argument to these macros is the integer value returned from wait() or waitpid(). WCOREDUMP(stat) If the value of WIFSIGNALED (stat) is non-zero, this macro evaluates to a non-zero value if a core image of the terminated child was created. WEXITSTATUS(stat) If the value of WIFEXITED(stat) is non-zero, this macro evaluates to the exit code that the child process passed to _exit() (see exit(2)) or exit(3C), or the value that the child process returned from main. WIFCONTINUED(stat) Evaluates to a non-zero value if status was returned for a child process that has continued. WIFEXITED(stat) Evaluates to a non-zero value if status was returned for a child process that terminated normally. WIFSIGNALED(stat) Evaluates to a non-zero value if status was returned for a child process that terminated due to the receipt of a signal. WIFSTOPPED(stat) Evaluates to a non-zero value if status was returned for a child process that is currently stopped. WSTOPSIG(stat) If the value of WIFSTOPPED(stat) is non-zero, this macro evaluates to the number of the signal that caused the child process to stop. WTERMSIG(stat) If the value of WIFSIGNALED(stat) is non-zero, this macro evaluates to the number of the signal that caused the termination of the child process. The <sys/wait.h> header defines the symbolic constants listed below for use with waitpid(3C). WNOHANG Do not hang if no status is available; return immediately. WUNTRACED Report status of stopped child process. The symbolic constants listed below are defined as possible values for the options argument to waitid(2). WEXITED Wait for processes that have exited. WSTOPPED Status is returned for any child that has stopped upon receipt of a signal. WCONTINUED Status is returned for any child that was stopped and has been continued. WNOHANG Return immediately if there are no children to wait for. WNOWAIT Keep the process whose status is returned in infop in a waitable state. The type idtype_t is defined as an enumeration type whose possible values include the following: P_ALL P_PID P_PGID The id_t and pid_t types are defined as described in <sys/types.h>. The siginfo_t type is defined as described in <signal.h>. The rusage structure is defined as described in <sys/resource.h>. Inclusion of the <sys/wait.h> header can also make visible all symbols from <signal.h> and <sys/resource.h>. ATTRIBUTES
See attributes(5) for descriptions of the following attributes: +-----------------------------+-----------------------------+ | ATTRIBUTE TYPE | ATTRIBUTE VALUE | +-----------------------------+-----------------------------+ |Interface Stability |Standard | +-----------------------------+-----------------------------+ SEE ALSO
exit(2), waitid(2), exit(3C), wait(3C), waitpid(3C),attributes(5), standards(5) SunOS 5.10 10 Sep 2004 wait.h(3HEAD)
All times are GMT -4. The time now is 05:31 PM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy