/* $OpenBSD: ttyio.c,v 1.31 2006/04/03 05:03:34 deraadt Exp $ */ /* This file is in the public domain. */ /* * POSIX terminal I/O. * * The functions in this file negotiate with the operating system for * keyboard characters, and write characters to the display in a barely * buffered fashion. */ #include "def.h" #include <sys/types.h> #include <sys/time.h> #include <sys/ioctl.h> #include <fcntl.h> #include <termios.h> #include <term.h> #define NOBUF 512 /* Output buffer size. */ #ifndef TCSASOFT #define TCSASOFT 0 #endif int ttstarted; char obuf[NOBUF]; /* Output buffer. */ size_t nobuf; /* Buffer count. */ struct termios oldtty; /* POSIX tty settings. */ struct termios newtty; int nrow; /* Terminal size, rows. */ int ncol; /* Terminal size, columns. */ /* * This function gets called once, to set up the terminal. * On systems w/o TCSASOFT we turn off off flow control, * which isn't really the right thing to do. */ void ttopen(void) { if (!isatty(STDIN_FILENO) || !isatty(STDOUT_FILENO)) panic("standard input and output must be a terminal"); if (ttraw() == FALSE) panic("aborting due to terminal initialize failure"); } /* * This function sets the terminal to RAW mode, as defined for the current * shell. This is called both by ttopen() above and by spawncli() to * get the current terminal settings and then change them to what * mg expects. Thus, tty changes done while spawncli() is in effect * will be reflected in mg. */ int ttraw(void) { if (tcgetattr(0, &oldtty) < 0) { ewprintf("ttopen can't get terminal attributes"); return (FALSE); } (void)memcpy(&newtty, &oldtty, sizeof(newtty)); /* Set terminal to 'raw' mode and ignore a 'break' */ newtty.c_cc[VMIN] = 1; newtty.c_cc[VTIME] = 0; newtty.c_iflag |= IGNBRK; newtty.c_iflag &= ~(BRKINT | PARMRK | INLCR | IGNCR | ICRNL | IXON); newtty.c_oflag &= ~OPOST; newtty.c_lflag &= ~(ECHO | ECHONL | ICANON | ISIG | IEXTEN); #if !TCSASOFT /* * If we don't have TCSASOFT, force terminal to * 8 bits, no parity. */ newtty.c_iflag &= ~ISTRIP; newtty.c_cflag &= ~(CSIZE | PARENB); newtty.c_cflag |= CS8; #endif if (tcsetattr(0, TCSASOFT | TCSADRAIN, &newtty) < 0) { ewprintf("ttopen can't tcsetattr"); return (FALSE); } ttstarted = 1; return (TRUE); } /* * This function gets called just before we go back home to the shell. * Put all of the terminal parameters back. * Under UN*X this just calls ttcooked(), but the ttclose() hook is in * because vttidy() in display.c expects it for portability reasons. */ void ttclose(void) { if (ttstarted) { if (ttcooked() == FALSE) panic(""); /* ttcooked() already printf'd */ ttstarted = 0; } } /* * This function restores all terminal settings to their default values, * in anticipation of exiting or suspending the editor. */ int ttcooked(void) { ttflush(); if (tcsetattr(0, TCSASOFT | TCSADRAIN, &oldtty) < 0) { ewprintf("ttclose can't tcsetattr"); return (FALSE); } return (TRUE); } /* * Write character to the display. Characters are buffered up, * to make things a little bit more efficient. */ int ttputc(int c) { if (nobuf >= NOBUF) ttflush(); obuf[nobuf++] = c; return (c); } /* * Flush output. */ void ttflush(void) { ssize_t written; char *buf = obuf; if (nobuf == 0) return; while ((written = write(fileno(stdout), buf, nobuf)) != nobuf) { if (written == -1) panic("ttflush write failed"); buf += written; nobuf -= written; } nobuf = 0; } /* * Read character from terminal. All 8 bits are returned, so that you * can use a multi-national terminal. */ int ttgetc(void) { char c; ssize_t ret; do { ret = read(STDIN_FILENO, &c, 1); if (ret == -1 && errno == EINTR) { if (winch_flag) { redraw(0, 0); winch_flag = 0; } } else if (ret == 1) break; } while (1); return ((int) c) & 0xFF; } /* * Returns TRUE if there are characters waiting to be read. */ int charswaiting(void) { int x; return ((ioctl(0, FIONREAD, &x) < 0) ? 0 : x); } /* * panic - just exit, as quickly as we can. */ void panic(char *s) { ttclose(); (void) fputs("panic: ", stderr); (void) fputs(s, stderr); (void) fputc('\n', stderr); exit(1); } /* * This function returns FALSE if any characters have showed up on the * tty before 'msec' milliseconds. */ int ttwait(int msec) { fd_set readfds; struct timeval tmout; FD_ZERO(&readfds); FD_SET(0, &readfds); tmout.tv_sec = msec/1000; tmout.tv_usec = msec - tmout.tv_sec * 1000; if ((select(1, &readfds, NULL, NULL, &tmout)) == 0) return (TRUE); return (FALSE); }