Minix1.5/commands/ibm/term.c
/* term - terminal simulator Author: Andy Tanenbaum */
/* This program allows the user to turn a MINIX system into a dumb
* terminal to communicate with a remote computer through one of the ttys.
* It forks into two processes. The parent sits in a tight loop copying
* from stdin to the tty. The child sits in a tight loop copying from
* the tty to stdout.
*
* 2 Sept 88 BDE (Bruce D. Evans): Massive changes to make current settings the
* default, allow any file as the "tty", support fancy baud rates and remove
* references to and dependencies on modems and keyboards, so (e.g.)
* a local login on /dev/tty1 can do an external login on /dev/tty2.
*
* 3 Sept 88 BDE: Split parent again to main process copies from stdin to a
* pipe which is copied to the tty. This stops a blocked write to the
* tty from hanging the program.
*
* 11 Oct 88 BDE: Cleaned up baud rates and parity stripping.
*
* Example usage:
* term : baud, bits/char, parity from /dev/tty1
* term 9600 7 even : 9600 baud, 7 bits/char, even parity
* term odd 300 7 : 300 baud, 7 bits/char, odd parity
* term /dev/tty2 : use /dev/tty2 rather than /dev/tty1
* : Any argument starting with "/" is
* : taken as the communication device.
*/
#include <sys/types.h>
#include <minix/config.h>
#include <fcntl.h>
#include <sgtty.h>
#include <signal.h>
#define MAXARGS 3 /* maximum number of uart params */
#define CHUNK 1024 /* how much to read at once */
#define NULL 0
/* Hack some new baud rates for Minix. Minix uses a divide-by-100 encoding. */
#define B200 2
#define B600 6
#define B1800 18
#define B3600 36
#define B7200 72
#define B19200 192
#define EXTA 192
/* We can't handle some standard (slow) V7 speeds and speeds above 25500 since
* since the speed is packed into a char :-(. Trap them with an illegal value.
*/
#define B50 0
#define B75 0
#define B134 0
#define EXTB 0
#define B38400 0
#define B57600 0
#define B115200 0
int commfd; /* open file no. for comm device */
int readpid; /* pid of child reading commfd */
struct sgttyb sgcommfd; /* saved terminal parameters for commfd */
struct sgttyb sgstdin; /* saved terminal parameters for stdin */
int writepid; /* pid of child writing commfd */
#if (MACHINE == ATARI)
char endseq[] = "Ou"; /* sequence to leave simulator */
#else
char endseq[] = "\033[G"; /* sequence to leave simulator */
#endif
/* Keypad '5', and must arrive in 1 piece */
struct param_s {
char *pattern;
int value;
char type;
#define BAD 0
#define BITS 1
#define NOSTRIP 2
#define PARITY 3
#define SPEED 4
}
params[] =
{
"5", BITS5, BITS,
"6", BITS6, BITS,
"7", BITS7, BITS,
"8", BITS8, BITS,
"even", EVENP, PARITY,
"odd", ODDP, PARITY,
"nostrip", 0, NOSTRIP,
"50", B50, SPEED,
"75", B75, SPEED,
"110", B110, SPEED,
"134", B134, SPEED,
"200", B200, SPEED,
"300", B300, SPEED,
"600", B600, SPEED,
"1200", B1200, SPEED,
"1800", B1800, SPEED,
"2400", B2400, SPEED,
"3600", B3600, SPEED,
"4800", B4800, SPEED,
"7200", B7200, SPEED,
"9600", B9600, SPEED,
"19200", B19200, SPEED,
"EXTA", EXTA, SPEED,
"EXTB", EXTB, SPEED,
"38400", B38400, SPEED,
"57600", B57600, SPEED,
"115200", B115200, SPEED,
"", 0, BAD, /* BAD type to end list */
};
unsigned char strip_parity = 1; /* nonzero to strip high bits before output */
int quit(); /* forward declare signal handler */
main(argc, argv)
int argc;
char *argv[];
{
char *commdev = NULL;
int i;
int pipefd[2];
sync();
for (i = 1; i < argc; ++i)
if (argv[i][0] == '/') {
if (commdev != NULL)
error("Too many communication devices", "");
commdev = argv[i];
}
if (commdev == NULL) {
i = MAXARGS + 1;
commdev = "/dev/tty1";
} else
i = MAXARGS + 2;
if (argc > i) error("Usage: term [baudrate] [data_bits] [parity]", "");
commfd = open(commdev, O_RDWR);
if (commfd < 0) error("Can't open ", commdev);
/* Save state of both devices before altering either (may be identical!). */
ioctl(0, TIOCGETP, &sgstdin);
ioctl(commfd, TIOCGETP, &sgcommfd);
set_mode(0, -1, -1, -1, &sgstdin); /* RAW mode on stdin, others
* current */
set_uart(argc, argv);
/* Main body of the terminal simulator. */
signal(SIGINT, quit);
signal(SIGPIPE, quit);
if (pipe(pipefd) < 0) error("Can't create pipe", "");
switch ((writepid = fork())) {
case -1:
error("Can't create process to write to comm device", "");
case 0:
/* Piped stdin to tty */
close(pipefd[1]);
copy(pipefd[0], "piped stdin", commfd, commdev, "");
}
close(pipefd[0]);
switch ((readpid = fork())) {
case -1:
error("Can't create process to read from comm device", "");
case 0:
/* Tty to stdout */
copy(commfd, commdev, 1, "stdout", "");
}
/* Stdin to pipe */
copy(0, "stdin", pipefd[1], "redirect stdin", endseq);
}
set_uart(argc, argv)
int argc;
char *argv[];
{
/* Set up the UART parameters. */
int i, j, bits, nbits, parity, nparities, speed, nspeeds;
char *arg;
register struct param_s *param;
/* Examine all the parameters and check for validity. */
nspeeds = nparities = nbits = 0;
speed = parity = bits = -1; /* -1 means use current value */
for (i = 1; i < argc; ++i) {
if ((arg = argv[i])[0] == '/') continue;
/* Check parameter for legality. */
for (j = 0, param = ¶ms[0];
param->type != BAD && strcmp(arg, param->pattern) != 0;
++j, ++param);
switch (param->type) {
case BAD:
error("Invalid parameter: ", arg);
case BITS:
bits = param->value;
if (++nbits > 1) error("Too many character sizes", "");
break;
case PARITY:
parity = param->value;
if (++nparities > 1) error("Too many parities", "");
break;
case SPEED:
speed = param->value;
if (speed == 0) error("Invalid speed: ", arg);
if (++nspeeds > 1) error("Too many speeds", "");
break;
case NOSTRIP: strip_parity = 0; break;
}
}
set_mode(commfd, speed, parity, bits, &sgcommfd);
}
set_mode(fd, speed, parity, bits, sgsavep)
int speed;
int parity;
int bits;
struct sgttyb *sgsavep;
{
/* Set open file fd to RAW mode with the given other modes. If fd is
* not a tty, this may do nothing but connecting ordinary files as
* ttys may have some use. */
struct sgttyb sgtty;
int tabs;
sgtty = *sgsavep;
tabs = sgtty.sg_flags & XTABS;
if (speed == -1) speed = sgtty.sg_ispeed;
if (parity == -1) parity = sgtty.sg_flags & (EVENP | ODDP);
if (bits == -1)
bits = sgtty.sg_flags & BITS8; /* BITS8 is actually a mask */
sgtty.sg_ispeed = speed;
sgtty.sg_ospeed = speed;
sgtty.sg_flags = RAW | parity | bits | tabs;
ioctl(fd, TIOCSETP, &sgtty);
}
copy(in, inname, out, outname, end)
int in;
char *inname;
int out;
char *outname;
char *end;
{
/* Copy from one open file to another. If the 'end' sequence is not "", and
* precisely matches the input, terminate the copy and various children.
* The end sequence is best provided by keyboard input from one of the
* special keys which always produces chars in a bunch. RAW mode almost
* guarantees exactly one keystroke's worth of input at a time.
*/
static char buf[CHUNK];
char *bufend;
register char *bufp;
int count;
int len;
len = strlen(end);
while (1) {
if ((count = read(in, buf, CHUNK)) <= 0) {
write2sn("Can't read from ", inname);
quit();
}
if (count == len && strncmp(buf, end, count) == 0) quit();
if (strip_parity) for (bufp = buf, bufend = bufp + count;
bufp < bufend; ++bufp)
*bufp &= 0x7F;
if (write(out, buf, count) != count) {
write2sn("Can't write to ", outname);
quit();
}
}
}
error(s1, s2)
char *s1;
char *s2;
{
write2sn(s1, s2);
exit(1);
}
nicequit()
{
exit(0);
}
quit()
{
ioctl(commfd, TIOCSETP, &sgcommfd);
ioctl(0, TIOCSETP, &sgstdin);
signal(SIGINT, nicequit); /* if not caught, sh prints extra newline */
kill(0, SIGINT);
nicequit();
}
write2sn(s1, s2)
{
write(1, s1, strlen(s1));
write(1, s2, strlen(s2));
write(1, "\r\n", 2);
}