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/*
Fork a subprocess, open a pty pair, and send the pty slave file
descriptor to the subprocess over an AF_UNIX socket. Invoke with
--debug to allow time to attach gdb to the child.
*/
#include "af_unix_hdr.h"
#include "pty_master_open.h"
#include "read_line.h"
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#define BUF_SIZE 100
#define MAX_SNAME 100 /* Maximum size for pty slave name */
int
main(int argc, char *argv[])
{
Boolean debug = FALSE;
pid_t pid;
int pipefd[2];
int pfd; /* parent's end */
int cfd; /* child's end */
if (argc > 1 && strcmp (argv[1], "--debug") == 0)
debug = TRUE;
if (socketpair (AF_UNIX, SOCK_STREAM, 0, pipefd) < 0)
errExit ("socketpair");
pfd = pipefd[1];
cfd = pipefd[0];
if ((pid = fork ()) < 0)
errExit ("fork");
else if (pid > 0) /* parent */
{
int mfd, sfd, junk;
char slname[MAX_SNAME];
if (close (cfd) < 0)
errExit ("close");
if ((mfd = ptyMasterOpen (slname, MAX_SNAME)) < 0)
errExit ("ptyMasterOpen");
if ((sfd = open (slname, O_RDWR | O_NOCTTY)) < 0)
errExit ("open");
if (debug)
{
printf ("parent pid %d, child pid %d, sleeping...\n", getpid (), pid);
sleep (30);
}
printf ("parent sending descriptor %d for %s to child\n", sfd, slname);
if (sendfd (pfd, sfd) < 0)
errExit ("sendfd");
if (close (sfd) < 0)
errMsg ("close");
if (write (mfd, "hello\n", 6) < 0)
errExit ("write");
/* Wait for child. */
if (read (pfd, &junk, sizeof junk) != sizeof junk)
errMsg ("read");
if (close (pfd) < 0)
errMsg ("close");
if (close (mfd) < 0)
errMsg ("close");
}
else /* child */
{
int fd, junk;
ssize_t nr;
char buf[BUF_SIZE];
if (close (pfd) < 0)
errExit ("close");
if (debug)
sleep (30);
/* Read fd from parent. */
fd = recvfd (cfd);
if (fd < 0)
errExit ("recvfd");
/* Read a line from fd. */
if ((nr = readLine (fd, buf, BUF_SIZE)) < 0)
{
close (fd);
errExit ("readLine");
}
/* Kill newline. */
buf[nr - 1] = '\0';
printf ("child read %zd bytes (including newline) from fd %d: %s\n", nr,
fd, buf);
if (close (fd) == -1)
errMsg ("close");
/* Tell parent we're done. */
if (write (cfd, &junk, sizeof junk) != sizeof junk)
errMsg ("write");
if (close (cfd) < 0)
errExit ("close");
}
}
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