cline@pnet01.cts.com (Ben Humphreys) (05/14/88)
As I have not been able to get any versions of talk to run on my SCO system, I
was forced to use write. But write is a bummer because it is bufferred. You
end up typing over top of each other. With program bundle.c in hand, I fig-
ured it wouldn't be too hard to make it write one character at a time to the
tty and stay in interactive mode until EOF. Boy was I wrong. I ended up
using read() and write() to read from the local terminal and write to the
remote terminal. But, as far as I can tell, write() doesn't actually write
until it receives a newline / carriage return. Even if I close() and re
open() the /dev/ttynn file, it still won't flush it's buffer. Is there a way
for force write() to flush the buffer without requiring a newline / carriage
return. Or, optionally, is there a way to get one character from the local
terminal (unbufferred) and write said character to the local terminal (again,
unbufferred)?
Anyone got a version of talk.c to run under SCO 2.1.3???
UUCP: {cbosgd, hplabs!hp-sdd, sdcsvax, nosc}!crash!cline01!benh
ARPA: crash!cline01!benh@nosc.mil
INET: cline@pnet01.CTS.COMben@idsnh.UUCP (Ben Smith) (05/15/88)
In article <2961@crash.cts.com> cline@pnet01.cts.com (Ben Humphreys) writes: | As I have not been able to get any versions of talk to run on my SCO system, I | was forced to use write. But write is a bummer because it is bufferred. The I/O has to be set to "cbreak" mode. See the termio & ioctl sections of your UNIX manual. The following program demonstrates the use of "cbreak": /* 1ch - sets terminal echo off and does decimal code echo of each keypress until newline is received - ben smith (uunet!idsnh!ben) - this program is being placed in the public domain by the author (bss) */ #include <stdio.h> #include <termio.h> char *descr[33] /* control character descriptions */ = { " NULL", "^A SOH ", "^B STX ", "^C ETX ", "^D EOT ", "^E ENQ ", "^F ACK ", "^G BEL ", "^H BS ", "^I HT ", "^J LF ", "^K VT ", "^L FF ", "^M CR ", "^N SO ", "^O SI ", "^P DLE ", "^Q DC1 ", "^R DC2 ", "^S DC3 ", "^T DC4 ", "^U NAK ", "^V SYN ", "^W ETB ", "^X CAN ", "^Y EM ", "^Z SUB ", "^[ ESC ", "^\\ FS ", "^] GS ", "^^ RS ", " SP " }; main() { int inchar, c; struct termio old, new; /* save old terminal config */ ioctl(0,TCGETA,&old); /* set up new terminal config */ /* first make a copy to modify */ ioctl(0,TCGETA,&new); /* then AND the controls */ new.c_lflag &= !(ICANON); new.c_cc[4] = new.c_cc[5] = '\01'; /* delay and buffer size */ /* and send out new config */ ioctl(0,TCSETAW,&new); /* now for the real part of the program - processing the keypresses */ do { c = getchar(); if ((c > 32 && c < 127) || (c > 160 && c < 255)) printf("decimal %3d octal %3o hex %2X = %c\n",c,c,c,c); else if (c >= 0 && c <= 32) printf("decimal %3d octal %3o hex %2X = %s\n",c,c,c,descr[c]); else if (c >= 128 && c <= 160) printf("decimal %3d octal %3o hex %2X = %s\n", c,c,c,descr[c-128]); else if (c == 127 || c == 255) printf("decimal %3d octal %3o hex %2X = DEL\n",c,c,c); }while (c != '\n'); /* reinstate old parameters before leaving */ ioctl(0,TCSETAW,&old); }
haugj@pigs.UUCP (John F. Haugh II) (05/16/88)
In article <2961@crash.cts.com>, cline@pnet01.UUCP writes: > As I have not been able to get any versions of talk to run on my SCO system, I > was forced to use write. [ much deleted ] > Anyone got a version of talk.c to run under SCO 2.1.3??? no, i have managed to get talk running under 2.2.1 on a 386. it's even been tested ;-) - john. -- The Beach Bum Big "D" Home for Wayward Hackers UUCP: ...!killer!rpp386!jfh jfh@rpp386.uucp :DOMAIN "You are in a twisty little maze of UUCP connections, all alike" -- fortune
abcscnge@csuna.UUCP (Scott "The Pseudo-Hacker" Neugroschl) (05/20/88)
In article <2961@crash.cts.com> cline@pnet01.cts.com (Ben Humphreys) writes: [ stuff about how write is buffered, and wants to go unbuffered input ] Use ioctl(). Set the terminal flags to: #include <sys/types.h> #include <sys/ioctl.h> #include <termio.h> struct termio ttyold, ttynew; /* get the terminal params twice */ if (ioctl(0,TCGETA,&ttyold) == -1 || ioctl(0,TCGETA,&ttynew) == -1) { perror("program"); exit(-1); } /* set up for unbuffered I/O */ ttynew.c_cc[VMIN] = 1; ttynew.c_cc[VTIME] = 0; ttynew.c_lflags &= ~ICANON; if (ioctl(0,TCSETAW,&ttynew) == -1) { perror("program"); exit(-1); } /* Stuff to talk to other user here */ /* clean up when done */ ioctl(0,TCSETAW,&ttyold); exit(0); /* done */ Note that you should catch SIGINT and probably SIGQUIT too, so that you can clean up gracefully before dropping dead. -- Scott "The Pseudo-Hacker" Neugroschl UUCP: ...!ihnp4!csun!csuna!abcscnge -- "They also surf who stand on waves" -- Disclaimers? We don't need no stinking disclaimers!!!