/*-------------------------------------------------------------------*/
/* testpipeforkexec.c                                                */
/* The pipe system call with fork and exec.                          */
/*-------------------------------------------------------------------*/
/* Error handling code omitted.                                      */
/*-------------------------------------------------------------------*/

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

#define BUFFER_LENGTH 256

int main(int argc, char *argv[])
{
   int iPid;
   int piPipeFd[2];
   int iOldFd0;
   char pcBuffer[BUFFER_LENGTH];

   pipe(piPipeFd);

   iPid = fork();

   if (iPid == 0)
   {
      char *ppcArgv[2];
      ppcArgv[0] = "date";
      ppcArgv[1] = NULL;
      close(piPipeFd[0]);
      close(1);
      dup(piPipeFd[1]);
      close(piPipeFd[1]);
      execvp("date", ppcArgv);
      perror(argv[0]);
      _exit(1);
   }

   close(piPipeFd[1]);
   iOldFd0 = dup(0);
   close(0);
   dup(piPipeFd[0]);
   close(piPipeFd[0]);
   fgets(pcBuffer, BUFFER_LENGTH, stdin);
   close(0);
   dup(iOldFd0);
   close(iOldFd0);

   printf("%s", pcBuffer);

   return 0;
}


/* Sample execution:

--> gcc -Wall -ansi -pedantic -o testpipeforkexec testpipeforkexec.c
--> testpipeforkexec
Mon Oct 21 22:30:47 EDT 2002
-->

*/