Linux 进程间通信(IPC):
Linux系统中除了进程和进程之间通信，我想大家也应该关注用户空间与内核空间是怎样通信的。例如说netlink等等。
除了传统进程间通信外像Socket通信也须要掌握的！
/*--------------------------------------------------------------------------
* Project: aipc.c
* Name: zwp
* Date: 2014/6
*-------------------------------------------------------------------------*/
#include <sys/types.h>
#include <sys/wait.h>
#include <sys/socket.h>
#include <unistd.h>
#include <signal.h>
#include <stdlib.h>
#include <stdio.h>
#define MAXLINE 1024
static void sig_pipe(int);
int s_pipe(int fd[2]);
int main(void)
{
int n, fd[2];
pid_t pid;
char line[MAXLINE];
if(signal(SIGPIPE, sig_pipe) == SIG_ERR)
printf("signal error...\n");
if(s_pipe(fd) < 0)
printf("pipe error...\n");
else if(pid > 0)
{
close(fd[1]);
while(fgets(line, MAXLINE, stdin) != NULL)
{
n = strlen(line);
if(write(fd[0], line, MAXLINE) != n)
printf("write error from pipe...\n");
if((n = read(fd[0], line, MAXLINE)) < 0)
printf("read arror from pipe...\n");
if(n == 0)
{
printf("child closed pipe...\n");
break;
}
line[n] = 0;
if(fputs(line, stdout) == EOF)
printf("fputs error...\n");
}
if(ferror(stdin))
printf("fgets error on stdin...\n");
exit(0);
}
else
{
close(fd[0]);
if(fd[1] != STDIN_FILENO)
{
if(dup2(fd[1], STDIN_FILENO) != STDIN_FILENO)
printf("dup2 error to stdin...\n");
}
if(fd[1] != STDOUT_FILENO)
{
if(dup2(fd[1], STDOUT_FILENO) != STDOUT_FILENO)
printf("dup2 error tostdout..\n");
}
if(execl("./add2", "add2", NULL) < 0)
printf("execl error...\n");
}
}
int s_pipe(int fd[2])
{
return (socketpair(AF_UNIX, SOCK_STREAM, 0, fd));
}
static void sig_pipe(int sign)
{
printf("SIGPIPE caught...\n");
exit(1);
}
来源：https://www.cnblogs.com/zhchoutai/p/7001684.html