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#define _XOPEN_SOURCE 600
#define _DEFAULT_SOURCE
#include <sys/select.h>
#include <sys/wait.h>
#include <sys/epoll.h>
#include <fcntl.h>
#include <termios.h>
#include <unistd.h>
#include <pty.h>
#include <errno.h>
#include <err.h>
#include <stdio.h>
#include <string.h>
#include <stdbool.h>
#include <stdlib.h>
static char buf[BUFSIZ] = { 0 };
static int
writeall(int fd, char *buffer, size_t size)
{
ssize_t nbytes;
while (size) {
nbytes = write(fd, buffer, size);
if (nbytes <= 0) return 1;
buffer += nbytes;
size -= nbytes;
}
return 0;
}
static int
fwd(int in, int out)
{
static char *buffer = NULL;
ssize_t got, i, last;
if (!buffer) {
buffer = malloc(BUFSIZ);
if (!buffer) err(1, "malloc");
}
do {
got = read(in, buffer, sizeof(buffer));
if (got < 0) return 1;
if (writeall(out, buffer, got))
return 1;
} while (got == sizeof(buffer));
return 0;
}
static void
mitm(int pts)
{
fd_set fds;
while (1) {
FD_ZERO(&fds);
FD_SET(0, &fds);
FD_SET(pts, &fds);
if (select(pts + 1, &fds, 0, 0, 0) == -1) {
if (errno == EINTR) continue;
return;
}
if (FD_ISSET(0, &fds)) { /* stdin -> ptty */
if (fwd(0, pts)) return;
}
if (FD_ISSET(pts, &fds)) { /* ptty -> stdout + pipe */
if (fwd(pts, 1)) return;
}
}
}
static void
usage(int rc)
{
fprintf(stderr, "Usage: apty [-r ROWS] [-c COLS] [-h] [--] CMD\n");
exit(rc);
}
int
main(int argc, char **argv)
{
char **arg, **cmd;
struct termios termios = {0};
struct winsize winsize = {0};
int exitcode;
int master, tty;
pid_t child;
if (argc <= 1) usage(1);
winsize.ws_col = 120;
winsize.ws_row = 80;
cfmakeraw(&termios);
if (isatty(STDIN_FILENO)) {
if (ioctl(STDIN_FILENO, TIOCGWINSZ, &winsize))
err(1, "tcgetwinsize");
if (tcgetattr(STDIN_FILENO, &termios))
err(1, "tcgettattr");
termios.c_lflag &= ~ICANON;
if (tcsetattr(STDIN_FILENO, TCSANOW, &termios))
err(1, "tcsetattr");
}
for (arg = argv + 1; *arg; arg++) {
if (!strcmp(*arg, "-t") || !strcmp(*arg, "--tty")) {
if (!isatty(STDIN_FILENO)) {
tty = open("/dev/tty", O_RDONLY);
if (tty < 0) err(1, "open /dev/tty");
if (tcgetattr(tty, &termios))
err(1, "tcgetattr tty");
if (ioctl(tty, TIOCGWINSZ, &winsize))
err(1, "tcgetwinsize tty");
close(tty);
}
} else if (!strcmp(*arg, "-c") || !strcmp(*arg, "--cols")) {
winsize.ws_col = atoi(*++arg);
} else if (!strcmp(*arg, "-r") || !strcmp(*arg, "--rows")) {
winsize.ws_row = atoi(*++arg);
} else if (!strcmp(*arg, "-h") || !strcmp(*arg, "--help")) {
usage(0);
} else if (!strcmp(*arg, "--")) {
arg++;
break;
} else {
break;
}
}
if (!*arg) errx(1, "missing command");
cmd = arg;
child = forkpty(&master, NULL, &termios, &winsize);
if (child < 0) err(1, "fork");
if (child == 0) {
execvp(*cmd, cmd);
err(1, "execvp %s", *cmd);
} else {
mitm(master);
waitpid(child, &exitcode, 0);
close(master);
}
return exitcode;
}
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