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/* dup.c
*
* Child piping input to parent
*
*/
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <wait.h>
extern char **environ;
int main(int argc, char **argv)
{
pid_t pid;
int stat_loc;
int pfds[2];
int ret;
if (pipe(pfds) == 0)
{
pid = fork();
if (pid == -1)
{
perror("fork");
exit(EXIT_FAILURE);
}
if (!pid)
{
close(1); /* break the link to stdout, dup2 already kills this but meh */
dup2(pfds[1], 1); /* redirect stdout to pfds[1] */
close(pfds[1]); /* new stdout has been setup above, pfds[1] can be closed since it's a dup */
close(pfds[0]); /* child will not be reading anything from out pipe */
execlp("ls", "ls", "-1", NULL);
}
else
{
close(0); /* break the link to stdin */
dup2(pfds[0], 0); /* redirect stdin to pfds[0] */
close(pfds[0]); /* new stdin has been setup above, pfds[1] can be closed since it's a dup */
close(pfds[1]); /* parent will not be writing anything into our pipe */
ret = waitpid(pid, &stat_loc, WCONTINUED);
execlp("wc", "wc", "-l", NULL);
}
}
else
{
perror("pipe");
exit(EXIT_FAILURE);
}
ret = ret; /* hush the dumb compiler */
close(pfds[0]);
close(pfds[1]);
return 0;
}
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