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// See LICENSE for license details.
// xspike forks an xterm for spike's target machine console,
// preserving the current terminal for debugging.
#include "common.h"
#include <unistd.h>
#include <fcntl.h>
#include <signal.h>
#include <sys/wait.h>
#include <cstdio>
#include <climits>
#include <cstring>
#include <stdexcept>
static pid_t fork_spike(int tty_fd, char** argv);
static pid_t fork_xterm(int* tty_fd);
int main(int UNUSED argc, char** argv)
{
int tty_fd, wait_status, ret = -1;
pid_t xterm, spike;
static bool signal_exit = false;
auto handle_signal = [](int) { signal_exit = true; };
if ((xterm = fork_xterm(&tty_fd)) < 0)
{
fprintf(stderr, "could not open xterm\n");
goto out;
}
signal(SIGINT, handle_signal);
if ((spike = fork_spike(tty_fd, argv)) < 0)
{
fprintf(stderr, "could not open spike\n");
goto close_xterm;
}
while ((ret = waitpid(spike, &wait_status, 0)) < 0)
if (signal_exit)
break;
if (ret < 0) // signal_exit
kill(spike, SIGTERM);
else
ret = WIFEXITED(wait_status) ? WEXITSTATUS(wait_status) : -1;
close_xterm:
kill(-xterm, SIGTERM);
out:
return ret;
}
static pid_t fork_spike(int tty_fd, char** argv)
{
pid_t pid = fork();
if (pid < 0)
return -1;
if (pid == 0)
{
if (dup2(tty_fd, STDIN_FILENO) < 0 || dup2(tty_fd, STDOUT_FILENO) < 0)
return -1;
execvp("spike", argv);
return -1;
}
return pid;
}
static pid_t fork_xterm(int* tty_fd)
{
static const char cmd[] = "3>&1 xterm -title xspike -e sh -c 'tty 1>&3; termios-xspike'";
int fds[2];
if (pipe(fds) < 0)
return -1;
pid_t pid = fork();
if (pid < 0)
return -1;
if (pid == 0)
{
setpgid(0, 0);
if (dup2(fds[1], STDOUT_FILENO) < 0)
return -1;
execl("/bin/sh", "sh", "-c", cmd, NULL);
return -1;
}
char tty[PATH_MAX];
ssize_t ttylen = read(fds[0], tty, sizeof(tty));
if (ttylen <= 1 || tty[ttylen-1] != '\n')
return -1;
tty[ttylen-1] = '\0';
if ((*tty_fd = open(tty, O_RDWR)) < 0)
return -1;
return pid;
}
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