beos-runpiped.c

   1 #include  <fcntl.h>
   2 #include <unistd.h>
   3 #include <be/kernel/OS.h>
   4
   5 int main(int argc, char **argv)
   6 {
   7         int pid,fd1,fd2;
   8         sem_id sem1,sem2;
   9         sem1=create_sem(1,"piperun");
  10         sem2=create_sem(1,"piperun");
  11         if (sem1<B_NO_ERROR ||sem2<B_NO_ERROR) {
  12                 perror("create_sem");
  13                 exit(1);
  14         }
  15         acquire_sem(sem1);
  16         acquire_sem(sem2);
  17         pid=fork();
  18         if (pid==0) {
  19                 fd1=open("/pipe/1",O_WRONLY|O_CREAT,0666);
  20                 if (fd1==-1) {
  21                         perror("writer: /pipe/1");
  22                         _exit(1);
  23                 }
  24                 release_sem(sem1);
  25                 /* wait for other side to open the pipe 1 */
  26                 acquire_sem(sem2);
  27                 /* wait for creation of pipe 2 */
  28                 acquire_sem(sem1);
  29                 fd2=open("/pipe/2",O_RDONLY);
  30                 if (fd2==-1) {
  31                         perror("/pipe/2");
  32                         _exit(1);
  33                 }
  34                 release_sem(sem2);
  35                 dup2(fd2,0);
  36                 dup2(fd1,1);
  37                 system(argv[2]);
  38
  39                 _exit(1);
  40         }
  41         acquire_sem(sem1);
  42         fd1=open("/pipe/1",O_RDONLY);
  43         release_sem(sem2);
  44         if (fd1==-1) {
  45                 perror("/pipe/1");
  46                 exit(1);
  47         }
  48         fd2=open("/pipe/2",O_WRONLY|O_CREAT,0666);
  49         if (fd2==-1) {
  50                 perror("writer: /pipe/2");
  51                 exit(1);
  52         }
  53         release_sem(sem1);
  54         /* wait for child to open ... */
  55         acquire_sem(sem2);
  56         dup2(fd1,0);
  57         dup2(fd2,1);
  58         system(argv[1]);
  59         exit(0);
  60 }