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Help: how to call fork() in shell script? New to linux
Post 302698987 by Xiaoya on Tuesday 11th of September 2012 12:46:13 AM
09-11-2012
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Hi folks,
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int main()
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fork();
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fork();
printf("C\n");
}
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hi,
i tried the following source codes:
fork1.c:
main()
{
printf("demo of fork\n");
fork();
printf("hello");
}
output:
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hello hello
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hi all,
i tried the following source codes:
fork1.c:
main()
{
printf("demo of fork\n");
fork();
printf("hello");
}
output:
demo of fork
hello hello
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Hi
I wrote a simple fork program to illustrate the fork() system cal. here it is
#include<stdio.h>
#include<sys/stat.h>
#include<sys/types.h>
main()
{
int flag;
flag=fork();
if(flag==0)
{
printf("Child \n");
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Hi, I'm writing a shell script where I want to call fork(). However I wrote like this "var=fork()" in c style and got this error:
"syntax error near unexpected token `(' "
How could I call fork() in shell script? Thanks in advance.
Duplicate Post - Continue Here - Please Do Not Cross Post... (0 Replies)
Discussion started by: Xiaoya
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LEARN ABOUT BSD
pthread_atfork
PTHREAD_ATFORK(3) Library Functions Manual PTHREAD_ATFORK(3) NAME
pthread_atfork - register handlers to be called at fork(2) time SYNOPSIS
#include <pthread.h> int pthread_atfork(void (*prepare)(void), void (*parent)(void), void (*child)(void)); DESCRIPTION
pthread_atfork registers handler functions to be called just before and just after a new process is created with fork(2). The prepare han- dler will be called from the parent process, just before the new process is created. The parent handler will be called from the parent process, just before fork(2) returns. The child handler will be called from the child process, just before fork(2) returns. One or several of the three handlers prepare, parent and child can be given as NULL, meaning that no handler needs to be called at the cor- responding point. pthread_atfork can be called several times to install several sets of handlers. At fork(2) time, the prepare handlers are called in LIFO order (last added with pthread_atfork, first called before fork), while the parent and child handlers are called in FIFO order (first added, first called). To understand the purpose of pthread_atfork, recall that fork(2) duplicates the whole memory space, including mutexes in their current locking state, but only the calling thread: other threads are not running in the child process. The mutexes are not usable after the fork and must be initialized with pthread_mutex_init in the child process. This is a limitation of the current implementation and might or might not be present in future versions. RETURN VALUE
pthread_atfork returns 0 on success and a non-zero error code on error. ERRORS
ENOMEM insufficient memory available to register the handlers. AUTHOR
Xavier Leroy <Xavier.Leroy@inria.fr> SEE ALSO
fork(2), pthread_mutex_lock(3), pthread_mutex_unlock(3). LinuxThreads PTHREAD_ATFORK(3)