Linux進程間管道通訊，兩個子進程間的通訊

#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>

int main(void)
{
    int n;
    int status;
    pid_t pid_1, pid_2;
    int fd[2];
    char buffer[100] = "main function!";
    
    if(pipe(fd) < 0)
    {
        perror("pipe failed!");
        exit(1);
    }
    
    if((pid_1 = fork()) < 0)
    {
        perror("fork 1 failed!");
        exit(1);
    }
    else if(pid_1 == 0)
    {
        strcpy(buffer, "info from process 1\n");
        //printf("%d\n", strlen(buffer));
        close(fd[0]);
        write(fd[1], buffer, strlen(buffer));
        exit(0);
    }
    if((pid_2 = fork()) < 0)
    {
        perror("fork 2 failed!");
        exit(1);
    }
    else if(pid_2 == 0)
    {
        close(fd[1]);
        n = read(fd[0], buffer, 100);
        printf("%s", buffer);
        exit(0);
    }
    
    waitpid(pid_1, &status, 0);
    waitpid(pid_2, &status, 0);
    
    printf("%s\n", buffer);
    
    return 0;
}

父進程分出的兩個子進程之間能夠經過pipe管道通訊。父進程和子進程也能夠經過pipe管道通訊。

可是要注意的是在父進程中定義的buffer數組在父進程分出子進程的時候會爲兩個子進程各自clone一份，因此在子進程中對buffer的操做不會影響父進程和另外子進程中的buffer