313 lines
7.8 KiB
C
313 lines
7.8 KiB
C
/* term - terminal simulator Author: Andy Tanenbaum */
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/* This program allows the user to turn a MINIX system into a dumb
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* terminal to communicate with a remote computer through one of the ttys.
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* It forks into two processes. The parent sits in a tight loop copying
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* from stdin to the tty. The child sits in a tight loop copying from
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* the tty to stdout.
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*
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* 2 Sept 88 BDE (Bruce D. Evans): Massive changes to make current settings the
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* default, allow any file as the "tty", support fancy baud rates and remove
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* references to and dependencies on modems and keyboards, so (e.g.)
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* a local login on /dev/tty1 can do an external login on /dev/tty2.
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*
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* 3 Sept 88 BDE: Split parent again to main process copies from stdin to a
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* pipe which is copied to the tty. This stops a blocked write to the
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* tty from hanging the program.
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*
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* 11 Oct 88 BDE: Cleaned up baud rates and parity stripping.
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*
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* Example usage:
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* term : baud, bits/char, parity from /dev/tty1
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* term 9600 7 even : 9600 baud, 7 bits/char, even parity
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* term odd 300 7 : 300 baud, 7 bits/char, odd parity
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* term /dev/tty2 : use /dev/tty2 rather than /dev/tty1
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* : Any argument starting with "/" is
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* : taken as the communication device.
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*/
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#include <sys/types.h>
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#include <minix/config.h>
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#include <fcntl.h>
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#include <sgtty.h>
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#include <signal.h>
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#define MAXARGS 3 /* maximum number of uart params */
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#define CHUNK 1024 /* how much to read at once */
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#define NULL 0
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/* Hack some new baud rates for Minix. Minix uses a divide-by-100 encoding. */
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#define B200 2
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#define B600 6
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#define B1800 18
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#define B3600 36
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#define B7200 72
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#define B19200 192
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#define EXTA 192
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/* We can't handle some standard (slow) V7 speeds and speeds above 25500 since
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* since the speed is packed into a char :-(. Trap them with an illegal value.
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*/
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#define B50 0
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#define B75 0
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#define B134 0
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#define EXTB 0
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#define B38400 0
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#define B57600 0
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#define B115200 0
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int commfd; /* open file no. for comm device */
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int readpid; /* pid of child reading commfd */
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struct sgttyb sgcommfd; /* saved terminal parameters for commfd */
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struct sgttyb sgstdin; /* saved terminal parameters for stdin */
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int writepid; /* pid of child writing commfd */
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#if (MACHINE == ATARI)
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char endseq[] = "Ou"; /* sequence to leave simulator */
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#else
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char endseq[] = "\033[G"; /* sequence to leave simulator */
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#endif
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/* Keypad '5', and must arrive in 1 piece */
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struct param_s {
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char *pattern;
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int value;
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char type;
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#define BAD 0
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#define BITS 1
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#define NOSTRIP 2
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#define PARITY 3
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#define SPEED 4
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}
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params[] =
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{
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"5", BITS5, BITS,
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"6", BITS6, BITS,
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"7", BITS7, BITS,
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"8", BITS8, BITS,
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"even", EVENP, PARITY,
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"odd", ODDP, PARITY,
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"nostrip", 0, NOSTRIP,
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"50", B50, SPEED,
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"75", B75, SPEED,
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"110", B110, SPEED,
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"134", B134, SPEED,
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"200", B200, SPEED,
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"300", B300, SPEED,
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"600", B600, SPEED,
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"1200", B1200, SPEED,
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"1800", B1800, SPEED,
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"2400", B2400, SPEED,
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"3600", B3600, SPEED,
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"4800", B4800, SPEED,
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"7200", B7200, SPEED,
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"9600", B9600, SPEED,
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"19200", B19200, SPEED,
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"EXTA", EXTA, SPEED,
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"EXTB", EXTB, SPEED,
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"38400", B38400, SPEED,
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"57600", B57600, SPEED,
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"115200", B115200, SPEED,
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"", 0, BAD, /* BAD type to end list */
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};
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unsigned char strip_parity = 1; /* nonzero to strip high bits before output */
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int quit(); /* forward declare signal handler */
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main(argc, argv)
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int argc;
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char *argv[];
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{
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char *commdev = NULL;
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int i;
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int pipefd[2];
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sync();
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for (i = 1; i < argc; ++i)
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if (argv[i][0] == '/') {
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if (commdev != NULL)
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error("Too many communication devices", "");
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commdev = argv[i];
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}
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if (commdev == NULL) {
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i = MAXARGS + 1;
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commdev = "/dev/tty1";
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} else
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i = MAXARGS + 2;
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if (argc > i) error("Usage: term [baudrate] [data_bits] [parity]", "");
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commfd = open(commdev, O_RDWR);
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if (commfd < 0) error("Can't open ", commdev);
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/* Save state of both devices before altering either (may be identical!). */
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ioctl(0, TIOCGETP, &sgstdin);
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ioctl(commfd, TIOCGETP, &sgcommfd);
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set_mode(0, -1, -1, -1, &sgstdin); /* RAW mode on stdin, others
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* current */
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set_uart(argc, argv);
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/* Main body of the terminal simulator. */
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signal(SIGINT, quit);
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signal(SIGPIPE, quit);
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if (pipe(pipefd) < 0) error("Can't create pipe", "");
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switch ((writepid = fork())) {
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case -1:
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error("Can't create process to write to comm device", "");
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case 0:
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/* Piped stdin to tty */
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close(pipefd[1]);
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copy(pipefd[0], "piped stdin", commfd, commdev, "");
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}
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close(pipefd[0]);
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switch ((readpid = fork())) {
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case -1:
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error("Can't create process to read from comm device", "");
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case 0:
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/* Tty to stdout */
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copy(commfd, commdev, 1, "stdout", "");
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}
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/* Stdin to pipe */
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copy(0, "stdin", pipefd[1], "redirect stdin", endseq);
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}
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set_uart(argc, argv)
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int argc;
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char *argv[];
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{
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/* Set up the UART parameters. */
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int i, j, bits, nbits, parity, nparities, speed, nspeeds;
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char *arg;
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register struct param_s *param;
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/* Examine all the parameters and check for validity. */
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nspeeds = nparities = nbits = 0;
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speed = parity = bits = -1; /* -1 means use current value */
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for (i = 1; i < argc; ++i) {
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if ((arg = argv[i])[0] == '/') continue;
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/* Check parameter for legality. */
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for (j = 0, param = ¶ms[0];
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param->type != BAD && strcmp(arg, param->pattern) != 0;
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++j, ++param);
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switch (param->type) {
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case BAD:
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error("Invalid parameter: ", arg);
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case BITS:
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bits = param->value;
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if (++nbits > 1) error("Too many character sizes", "");
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break;
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case PARITY:
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parity = param->value;
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if (++nparities > 1) error("Too many parities", "");
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break;
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case SPEED:
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speed = param->value;
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if (speed == 0) error("Invalid speed: ", arg);
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if (++nspeeds > 1) error("Too many speeds", "");
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break;
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case NOSTRIP: strip_parity = 0; break;
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}
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}
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set_mode(commfd, speed, parity, bits, &sgcommfd);
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}
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set_mode(fd, speed, parity, bits, sgsavep)
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int speed;
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int parity;
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int bits;
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struct sgttyb *sgsavep;
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{
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/* Set open file fd to RAW mode with the given other modes. If fd is
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* not a tty, this may do nothing but connecting ordinary files as
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* ttys may have some use. */
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struct sgttyb sgtty;
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int tabs;
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sgtty = *sgsavep;
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tabs = sgtty.sg_flags & XTABS;
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if (speed == -1) speed = sgtty.sg_ispeed;
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if (parity == -1) parity = sgtty.sg_flags & (EVENP | ODDP);
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if (bits == -1)
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bits = sgtty.sg_flags & BITS8; /* BITS8 is actually a mask */
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sgtty.sg_ispeed = speed;
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sgtty.sg_ospeed = speed;
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sgtty.sg_flags = RAW | parity | bits | tabs;
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ioctl(fd, TIOCSETP, &sgtty);
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}
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copy(in, inname, out, outname, end)
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int in;
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char *inname;
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int out;
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char *outname;
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char *end;
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{
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/* Copy from one open file to another. If the 'end' sequence is not "", and
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* precisely matches the input, terminate the copy and various children.
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* The end sequence is best provided by keyboard input from one of the
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* special keys which always produces chars in a bunch. RAW mode almost
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* guarantees exactly one keystroke's worth of input at a time.
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*/
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static char buf[CHUNK];
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char *bufend;
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register char *bufp;
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int count;
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int len;
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len = strlen(end);
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while (1) {
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if ((count = read(in, buf, CHUNK)) <= 0) {
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write2sn("Can't read from ", inname);
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quit();
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}
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if (count == len && strncmp(buf, end, count) == 0) quit();
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if (strip_parity) for (bufp = buf, bufend = bufp + count;
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bufp < bufend; ++bufp)
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*bufp &= 0x7F;
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if (write(out, buf, count) != count) {
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write2sn("Can't write to ", outname);
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quit();
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}
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}
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}
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error(s1, s2)
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char *s1;
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char *s2;
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{
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write2sn(s1, s2);
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exit(1);
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}
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nicequit()
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{
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exit(0);
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}
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quit()
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{
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ioctl(commfd, TIOCSETP, &sgcommfd);
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ioctl(0, TIOCSETP, &sgstdin);
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signal(SIGINT, nicequit); /* if not caught, sh prints extra newline */
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kill(0, SIGINT);
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nicequit();
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}
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write2sn(s1, s2)
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{
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write(1, s1, strlen(s1));
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write(1, s2, strlen(s2));
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write(1, "\r\n", 2);
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}
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