/* $OpenBSD: tty.c,v 1.18 2019/06/28 13:34:59 deraadt Exp $ */ #include <errno.h> #include <fcntl.h> #include <string.h> #include <unistd.h> #include "sh.h" #include "tty.h" int tty_fd = -1; /* dup'd tty file descriptor */ int tty_devtty; /* true if tty_fd is from /dev/tty */ struct termios tty_state; /* saved tty state */ void tty_close(void) { if (tty_fd >= 0) { close(tty_fd); tty_fd = -1; } } /* Initialize tty_fd. Used for saving/resetting tty modes upon * foreground job completion and for setting up tty process group. */ void tty_init(int init_ttystate) { int do_close = 1; int tfd; tty_close(); tty_devtty = 1; tfd = open("/dev/tty", O_RDWR, 0); if (tfd == -1) { tty_devtty = 0; warningf(false, "No controlling tty (open /dev/tty: %s)", strerror(errno)); do_close = 0; if (isatty(0)) tfd = 0; else if (isatty(2)) tfd = 2; else { warningf(false, "Can't find tty file descriptor"); return; } } if ((tty_fd = fcntl(tfd, F_DUPFD_CLOEXEC, FDBASE)) == -1) { warningf(false, "%s: dup of tty fd failed: %s", __func__, strerror(errno)); } else if (init_ttystate) tcgetattr(tty_fd, &tty_state); if (do_close) close(tfd); }