diff options
Diffstat (limited to 'lib/term.h')
| -rw-r--r-- | lib/term.h | 206 |
1 files changed, 206 insertions, 0 deletions
diff --git a/lib/term.h b/lib/term.h new file mode 100644 index 0000000..b3b1440 --- /dev/null +++ b/lib/term.h @@ -0,0 +1,206 @@ +/* + * Copyright (c) 2026 Dylan Araps + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in all + * copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + */ +#ifndef DYLAN_TERM_H +#define DYLAN_TERM_H + +#include <fcntl.h> +#include <signal.h> +#include <stdint.h> +#include <stdio.h> +#include <termios.h> +#include <unistd.h> + +#include <sys/ioctl.h> +#include <sys/select.h> +#include <sys/time.h> +#include <sys/wait.h> + +#include "util.h" +#include "vt.h" + +enum { + TERM_LOADED = 1 << 0, + TERM_RESIZE = 1 << 1, +}; + +static struct term { + struct termios o; + int fd; + int null; + volatile sig_atomic_t flag; + volatile sig_atomic_t dead; +} *TERM; + +static inline void +term_set_dead(struct term *t, int s) +{ + t->dead = 128 + s; +} + +static inline int +term_dead(const struct term *t) +{ + return t->dead; +} + +static inline int +term_resize(const struct term *t) +{ + return t->flag & TERM_RESIZE; +} + +static inline void +term_restore_on_signal(int s) +{ + if (!TERM) return; + if (!(TERM->flag & TERM_LOADED)) return; + term_set_dead(TERM, s); + tcsetattr(TERM->fd, TCSAFLUSH, &TERM->o); + + // + // TODO: Unhardcode this. + // +#define TERM_COOKED \ + S(VT_ED0 VT_BPASTE_OFF VT_DECAWM_Y VT_DECTCEM_Y VT_ALT_SCREEN_N) + write_all(TERM->fd, TERM_COOKED); + write_all(STDOUT_FILENO, TERM_COOKED); +} + +static inline void +term_signal_fatal(int s) +{ + term_restore_on_signal(s); + _exit(128 + s); +} + +static inline void +term_signal_crash(int s) +{ + term_restore_on_signal(s); + struct sigaction sa = {0}; + sa.sa_handler = SIG_DFL; + sigemptyset(&sa.sa_mask); + sigaction(s, &sa, NULL); + kill(getpid(), s); +} + +static inline void +term_signal_sigwinch(int s) +{ + (void) s; + if (TERM) TERM->flag |= TERM_RESIZE; +} + +static inline void +term_signal_setup(void) { + struct sigaction sa; + sigemptyset(&sa.sa_mask); + sa.sa_flags = SA_RESTART; + sa.sa_handler = term_signal_fatal; + sigaction(SIGINT, &sa, NULL); + sigaction(SIGTERM, &sa, NULL); + sigaction(SIGQUIT, &sa, NULL); + sa.sa_handler = term_signal_crash; + sigaction(SIGSEGV, &sa, NULL); + sigaction(SIGABRT, &sa, NULL); + sigaction(SIGBUS, &sa, NULL); + sigaction(SIGFPE, &sa, NULL); + sigaction(SIGILL, &sa, NULL); + sa.sa_handler = term_signal_sigwinch; + sigaction(SIGWINCH, &sa, NULL); +} + +static inline int +term_size_update(struct term *t, u16 *row, u16 *col) +{ + struct winsize ws; + if (ioctl(t->fd, TIOCGWINSZ, &ws) < 0) + return -1; + t->flag &= ~TERM_RESIZE; + *row = ws.ws_row; + *col = ws.ws_col; + return 0; +} + +static inline int +term_init_io(struct term *t) +{ + if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) + t->fd = STDIN_FILENO; + else if (isatty(STDIN_FILENO)) { + t->fd = open("/dev/tty", O_RDWR|O_CLOEXEC); + if (t->fd < 0) return -1; + } else { + t->fd = -1; + return -1; + } + t->null = open("/dev/null", O_WRONLY|O_CLOEXEC); + return t->null; +} + +static inline int +term_raw(const struct term *t) +{ + struct termios n = t->o; + n.c_iflag &= ~(BRKINT|ICRNL|INPCK|ISTRIP|IXON); + n.c_oflag &= ~(OPOST); + n.c_cflag |= (CS8); + n.c_lflag &= ~(ECHO|ICANON|IEXTEN|ISIG); + n.c_cc[VMIN] = 1; + n.c_cc[VTIME] = 0; + return tcsetattr(t->fd, TCSAFLUSH, &n); +} + +static inline int +term_cooked(struct term *t) +{ + assert(t->flag & TERM_LOADED); + return tcsetattr(t->fd, TCSAFLUSH, &t->o); +} + +static inline int +term_init(struct term *t) +{ + if (term_init_io(t) < 0) return -1; + if (tcgetattr(t->fd, &t->o) < 0) return -1; + TERM = t; + t->flag |= TERM_LOADED; + term_signal_setup(); + return 0; +} + +static inline void +term_reap(void) +{ + for (int st; waitpid(-1, &st, WNOHANG) > 0; ); +} + +static inline void +term_destroy(const struct term *t) +{ + if (t->fd >= 0) close(t->fd); + if (t->null >= 0) close(t->null); + TERM = NULL; +} + +#endif // DYLAN_TERM_H + |