jules@iisat.UUCP (Jules d'Entremont) (06/05/89)
A friend of mine is converting some programs from Turbo Pascal 5.0 to
work in Unix C. He's having difficulty translating a Turbo Pascal
function (getch ?) which reads in a character from the keyboard unechoed,
and without waiting for a carriage return. I told him to use curses and
set cbreak() and noecho() modes. He thinks he shouldn't have to invoke
curses for such a simple task. Is there another way to do this? What
is the best, most portable way to do it?
--
Jules d'Entremont Phone: 454-5631 (Home) 465-5535 (Office)
UUCP: {uunet,utai,watmath}!dalcs!iisat!jules
Bitnet/Uucp: jules@iisat.uucp
Arpanet: jules%iisat.uucp@uunet.uu.netkucharsk@uts.amdahl.com (William Kucharski) (06/06/89)
Here's a program which demonstrates one way of doing things:
#include <stdio.h>
#include <termio.h>
main()
{
int a,c;
char ch[BUF];
struct termio o,t;
if (ioctl(0, TCGETA, &o))
perror("ioctl: get");
t = o;
t.c_lflag = 0; /* shut off everything */
t.c_cc[VEOF] = 1; /* MIN chars == 1 */
if (ioctl(0, TCSETA, &t))
perror("ioctl: set");
for (a = 0; a < BUF; a++) {
c = getc(stdin);
ch[a] = (char) c;
printf(".");
}
ch[BUF] = '\0'; /* NULL terminate it */
printf("\n%s\n", ch);
if (ioctl(0, TCSETA, &o))
perror("ioctl: set back");
}
--
William Kucharski
ARPA: kucharsk@uts.amdahl.com
UUCP: ...!{ames,decwrl,sun,uunet}!amdahl!kucharsk
Disclaimer: The opinions expressed above are my own, and may not agree with
those of any other sentient being, not to mention those of my
employer. So there.vijay@bradley.UUCP (06/07/89)
>Written 9:44 pm Jun 4, 1989 by jules@iisat.UUCP >/* ---------- "To curse or not to curse" ---------- */ >A friend of mine is converting some programs from Turbo Pascal 5.0 to >work in Unix C. He's having difficulty translating a Turbo Pascal >function (getch ?) which reads in a character from the keyboard unechoed, >and without waiting for a carriage return. I told him to use curses and >set cbreak() and noecho() modes. He thinks he shouldn't have to invoke >curses for such a simple task. Is there another way to do this? What >is the best, most portable way to do it? > >-- >Jules d'Entremont Phone: 454-5631 (Home) 465-5535 (Office) >Written 12:46 pm Jun 5, 1989 by kucharsk@uts.amdahl.com >Here's a program which demonstrates one way of doing things: > >#include <stdio.h> >#include <termio.h> ^^^^^^^^^^^^^^^^??? > >main() >{ > ... >} Where is the file termio.h? It is not there in /usr/include. I am using UNIX 4.3 BSD Thanx =============================================================I / / E-mail: vijay@bradley.edu I / / * * ___ ...!uiucdcs!bradley!vijay I / / / / / / / / I===================================I //___/___/__/_\/__/__/ I "A duck walks in a drug store and / / I says. 'Give me a chapstick, and / / I put it on my bill!'" __/ __/ I - Judge Harry Stone, Night Court ===============================================================
jiii@visdc.UUCP (John E Van Deusen III) (06/07/89)
In article <36@iisat.UUCP> jules@iisat.UUCP (Jules d'Entremont) writes: > > ... converting some programs from Turbo Pascal 5.0 to work in Unix C > [and] having difficulty translating a Turbo Pascal function (getch ?) > which reads in a character from the keyboard unechoed, ... without > waiting for a carriage return. ... What is the best, most portable > way to do it? There are two fundamental differences in the I/O handling of Pascal and of UNIX/C. First of all, Pascal does not really have a universal standard I/O interface. There have evolved many extensions to the language, and (getch ?) is one of those. As of the time I gave up in disgust, scrapped thousands of lines of Pascal systems code, and started using C exclusively; that function was not in common use. If (getch ?) works like getchar(3S) and returns a new line character to denote the end of a line, then an emulation should be possible using ioctl(2). A read(2) in C that has a positive return value provides no information about the EOF status of the file. In Pascal the return of the eof() and eoln() functions must be available immediately after the file is reset or read. This is clearly untenable for purposes of terminal I/O, because it requires prescient knowledge. The solution that was adopted is to cheat. After the reset() of a terminal, the eof() and eoln() functions return false. Any read(x_char) that results in an EOF condition, causes a blank to be assigned to x_char, and then eoln() and eof() return true. Because of this, Pascal can not distinguish a single blank from an empty line or an empty file. This does, however, enable a function like (getch ?) to be implemented, since input can be stolen from the Pascal input file without risking a change in the eof() or eoln() returns. -- John E Van Deusen III, PO Box 9283, Boise, ID 83707, (208) 343-1865 uunet!visdc!jiii
mhoffman@infocenter.UUCP (Mike Hoffman) (06/09/89)
in article <1cIi02Ph32aV01@amdahl.uts.amdahl.com>, kucharsk@uts.amdahl.com (William Kucharski) says: > > Here's a program which demonstrates one way of doing things: > > #include <stdio.h> > #include <termio.h> > > main() > { > int a,c; > char ch[BUF]; > struct termio o,t; > > if (ioctl(0, TCGETA, &o)) > perror("ioctl: get"); > > t = o; > t.c_lflag = 0; /* shut off everything */ > t.c_cc[VEOF] = 1; /* MIN chars == 1 */ > > [rest of code deleted...] This works OK on every system I've worked on, but I understand that some unfortunate souls must work without the benefits of structure assignment. To make the code more portable for those systems without, a #define statement could indicate this capability: . . . #ifdef STRUCTURE_ASST t = o; /* copy structure in one swell foop */ #else t.c_iflag = o.c_iflag; /* copy element by element. . . */ t.c_oflag = o.c_oflag; t.c_cflag = o.c_cflag; t.c_lflag = 0; /* inserting the desired changes */ t.c_line = o.c_line; *t.cc = *o.cc; t.cc[VEOF] = 1; #endif . . . [rest of code] Michael J. Hoffman Voice: (407)255-8116 Manufacturing Engineering FAX: (407)255-8186 Encore Computer Corporation Email: mhoffman USnail: 100 N. Babcock St. UUCP: {uunet,codas!novavax,sun,pur-ee}!gould!mhoffman Melbourne, Fl 32935 "My opinions are my own and are not to be employed with those of my confuser."
brian@bradley.UUCP (06/13/89)
> /* Written 8:56 am Jun 9, 1989 by mhoffman@infocenter.UUCP */ > This works OK on every system I've worked on, but I understand that > some unfortunate souls must work without the benefits of structure > assignment. To make the code more portable for those systems > without, a #define statement could indicate this capability: > > . . . > > #ifdef STRUCTURE_ASST > t = o; /* copy structure in one swell foop */ > #else > t.c_iflag = o.c_iflag; /* copy element by element. . . */ > t.c_oflag = o.c_oflag; > t.c_cflag = o.c_cflag; > t.c_lflag = 0; /* inserting the desired changes */ > t.c_line = o.c_line; > *t.cc = *o.cc; > t.cc[VEOF] = 1; > #endif > . . . [rest of code] Wouldn't this work just as well: #ifdef STRUCTURE_ASST t = o; #else (void) memcpy((char *) &t, (char *) &o, sizeof(t)); #endif Brian Michael Wendt UUCP: {cepu,uiucdcs,noao}!bradley!brian Bradley University ARPA: cepu!bradley!brian@seas.ucla.edu (309) 677-2335 ICBM: 40 40' N 89 34' W "Down, down in the basement, we hear the sound of machines..."
guy@auspex.auspex.com (Guy Harris) (06/29/89)
> Wouldn't this work just as well: > >#ifdef STRUCTURE_ASST > t = o; >#else > (void) memcpy((char *) &t, (char *) &o, sizeof(t)); >#endif Not if your implementation doesn't have "memcpy", which was added to AT&T's UNIX C library *after* they added structure assignment to their compiler....