进程通信——管道

在父进程中用pipe()建立一条管道线，往管道里写一句话，两个子进程接收这句话。

#include<unistd.h>
#include<signal.h>
#include<stdio.h>
#include<stdlib.h>
#include<sys/wait.h>
int pid1,pid2;
int main()
{
    int fd[2];
    char OutPipe[100],InPipe[100];
  pipe(fd);
     while((pid1=fork())==-1);
     if(pid1==0)
  { 
     lockf(fd[1],1,0);
     sprintf(OutPipe,"child 1 process is sending message!");
     write(fd[1],OutPipe,50);
     sleep(5);
     lockf(fd[1],0,0);
     exit(0);
   }
     else
  {
          while((pid2=fork())==-1);
          if(pid2==0)
     { 
       lockf(fd[1],1,0);
       sprintf(OutPipe,"child 2 process is sending message!");
       write(fd[1],OutPipe,50);
       sleep(5);
       lockf(fd[1],0,0);
       exit(0);
      }
          else
     {
       wait(0);
       read(fd[0],InPipe,50);
       printf("%s
",InPipe);
       wait(0);
       read(fd[0],InPipe,50);
       printf("%s
",InPipe);
       exit(0);
     }
  }
}

#include<unistd.h>
#include<signal.h>
#include<stdio.h>
#include<stdlib.h>
#include<sys/wait.h>
int pid1,pid2;
int main()
{
    int fd[2];
    char OutPipe[100],OutPipe1[100],InPipe[100];
  pipe(fd);
     while((pid1=fork())==-1);
     if(pid1==0)
  { 
    //   wait(0);
       read(fd[0],InPipe,50);
       printf("pid1:
%s
",InPipe);     
exit(0);
// 
   }
     else
  {
          while((pid2=fork())==-1);
          if(pid2==0)
     {
       wait(0);
       read(fd[0],InPipe,50);
       printf("pid2:
%s
",InPipe);
       exit(0);
//
      }
          else
     {
     lockf(fd[1],1,0);
     sprintf(OutPipe,"child 1 process is sending message!");
     write(fd[1],OutPipe,50);
     sleep(1);
     lockf(fd[1],0,0); 
     sprintf(OutPipe1,"child 2 process is sending message!");
     write(fd[1],OutPipe1,50);
     exit(0);
//   
     }
  }
}