kbhit.txt

this is a mirrored site c-faq. thought might need offline

    if (kbhit()) {
      c = getch();
      mvprintw(1, 0, "%d: \'%c\' is pressed (count: %ld)\n", ++i, c, count);
      refresh();
      }
    }

  nocrmode();
  echo();
  endwin();        /* close curses... */
}
/* ---- Cut Here ---- */

--
Han Yun-Su, KAIST, Life Science    |   Life is short, DNA is long.
Molecular Genetics Laboratory      |   DNAs, recombine in the neuclus!
Tel: [phone], 4786              |   Slow and steady evolves the life.


Article 47456 of comp.lang.c:
Path: mdisea!uw-coco!uw-beaver!nntp.cs.ubc.ca!unixg.ubc.ca!erich.triumf.ca!advax
From: [e-mail] (A.Daviel)
Newsgroups: comp.lang.c
Subject: getch() for VMS
Date: 15 Nov 1993 12:43 PST
Organization: TRIUMF: Tri-University Meson Facility
Lines: 34
Distribution: world
Message-ID: <[e-mail]>
NNTP-Posting-Host: erich.triumf.ca
News-Software: VAX/VMS VNEWS 1.41    

I see in the FAQ that this is a frequently asked question (How does one do
a DOS-type getch() on machine yy?). I wrote this for VMS; I don't pretend 
that it is fast, elegant or even correct, but it seems to work.

/* function getch */
#include iodef  /* Input/Output defines */
#include descrip /* VMS string descriptors */

char getch()
{
int iosb[2] ; /* I/O status block */
static int ichan = 0 ; 

$DESCRIPTOR (lun,"SYS$INPUT") ;
char ikey ;
const read_noecho = IO$_READVBLK | IO$M_NOECHO ;
int stat ;

/* initialize channel if required */
if (ichan==0)
  {
  stat = sys$assign(&lun,&ichan,0,0) ; 
  if (stat!=1) lib$signal(stat) ;
  }

/* read one key */
stat = sys$qiow(0,ichan,read_noecho,&iosb,0,0,&ikey,1,0,0,0,0) ;
if (stat!=1) lib$signal(stat) ;
return (ikey) ;
}

--
 Andrew Daviel, Vancouver, Canada <[e-mail]>
  TRIUMF - home of the world's largest cyclotron


Article 14000 of comp.unix.programmer:
Path: mdisea!mmddvan!vanbc.wimsey.com!cyber2.cyberstore.ca!nntp.cs.ubc.ca!destroyer!caen!math.ohio-state.edu!cs.utexas.edu!uunet!pitt.edu!neurocog.lrdc.pitt.edu!hahn
From: [e-mail] (Mark Hahn)
Newsgroups: comp.unix.programmer
Subject: Re: getchar() without waiting for '\n'
Message-ID: <[e-mail]>
Date: 18 Nov 93 17:34:32 GMT
References: <[e-mail]> <[e-mail]> <[e-mail]>
Sender: [e-mail]
Lines: 30
X-Newsreader: TIN [version 1.2 PL2]

> : Jun Shih ([e-mail]) wrote:
> : : How can I make getchar() to get a single character with waiting for
> : : the newline (CR) char?   So after a user type a char, my progaram will
> : : respond right away.

here's a better and very portable way to do it:

#include <stdio.h>
#include <termios.h>

int main() {
    struct termios t, tOrg;
    char ch;

    tcgetattr(fileno(stdin), &t);
    tOrg = t;
    t.c_lflag &= ~(ECHO | ICANON);
    t.c_cc[VMIN] = 1;
    tcsetattr(fileno(stdin),TCSANOW,&t);

    while((ch = getchar()) != 'q') {
        fprintf(stderr,"character typed: %c\n", ch);
    }
    tcsetattr(fileno(stdin),TCSANOW,&tOrg);
    return 0;
}

regards, mark hahn.
--
this space intentionally left non-blank.        [e-mail]


Article 64646 of comp.lang.c:
Path: mdisea!mmddvan!vanbc.wimsey.com!cyber2.cyberstore.ca!math.ohio-state.edu!uwm.edu!msuinfo!harbinger.cc.monash.edu.au!giaeb!lee
From: [e-mail] (Lee Hollingworth)
Newsgroups: comp.lang.c
Subject: Re: VT100 - Immediate IO (on UNIX)
Date: 12 Jun 94 02:43:05 GMT
Organization: Monash University
Lines: 97
Message-ID: <lee.771388985@giaeb>
References: <[e-mail]>
NNTP-Posting-Host: giaeb.cc.monash.edu.au
X-Newsreader: NN version 6.5.0 #4 (NOV)

[e-mail] (A Blakie) writes:

>Does anybody know how we can read characters from the keyboard without
>waiting
>for a carriage return? If you have any solutions to my problem, or any
>commands
>that I may have overlooked to do this, then could you please write and tell
>me.

>ps : do these solutions wait until somebody presses a key? or just do a
>quick
>check (cf peek in basic)?

Here is my rendition, do with it what you may :-)

Lee.

#include <unistd.h>     // read()
#include <fcntl.h>      // setting keyboard flags
#include <sys/ioctl.h>
#include <termio.h>     // used to set terminal modes
#include <termios.h>

//
// two global variables for tty and keybrd control
//
static struct termio term_orig;
static int kbdflgs;

//
// function :   system_mode
// purpose  :   reset the system to what it was before input_mode was
//              called
//
void system_mode(void)
{
    if (ioctl(0, TCSETA, &term_orig) == -1) {
        return;
    }
    fcntl(0, F_SETFL, kbdflgs);
}

//
// function :   input_mode
// purpose  :   set the system into raw mode for keyboard i/o
// returns  :   0 - error
//              1 - no error
//
int input_mode(void)
{
    struct termio term;    // to avoid ^S ^Q processing

    //
    // get rid of XON/XOFF handling, echo, and other input processing
    //
    if (ioctl(0, TCGETA, &term) == -1) {
        return (0);
    }
    (void) ioctl(0, TCGETA, &term_orig);
    term.c_iflag = 0;
    term.c_oflag = 0;
    term.c_lflag = 0;
    term.c_cc[VMIN] = 1;
    term.c_cc[VTIME] = 0;
    if (ioctl(0, TCSETA, &term) == -1) {
        return (0);
    }
    kbdflgs = fcntl(0, F_GETFL, 0);
    //
    // no delay on reading stdin
    //
    int flags = fcntl(0, F_GETFL);
    flags &= ~O_NDELAY;
    fcntl(0, F_SETFL, flags);
    return (1);
}

//
// function :   getch
// purpose  :   read a single character from the keyboard without echo
// returns  :   the keybress character
//
int getch(void)
{
    unsigned char ch;

    input_mode();
    while (read(0, &ch, 1) != 1) ;
    system_mode();

    return (ch);
}

int main()
{
    return (getch());
}


Article 65878 of comp.lang.c:
Path: mdisea!mmddvan!vanbc.wimsey.com!deep.rsoft.bc.ca!sol.ctr.columbia.edu!howland.reston.ans.net!vixen.cso.uiuc.edu!uwm.edu!msuinfo!harbinger.cc.monash.edu.au!giaeb!lee
From: [e-mail] (Lee Hollingworth)
Newsgroups: comp.lang.c
Subject: Re: getchar()
Date: 25 Jun 94 10:07:29 GMT
Organization: Monash University
Lines: 104
Message-ID: <lee.772538849@giaeb>
References: <2uftsr$[e-mail]>
NNTP-Posting-Host: giaeb.cc.monash.edu.au
Keywords: getchar
X-Newsreader: NN version 6.5.0 #4 (NOV)

[e-mail] (Jeffrey Seifer) writes:

>Could someone please help me...

>I have been writing c for years on IBM pc's, and now I am writing
>under unix.  I have always used the function getch() to get a single
>character from stdin (getchar() waits for you to press return).  Is
>there a way to do this under unix?

The trouble is that reading without a CR is ver O/S specific.

Here is some code which does what you want and should compile on
most (?) UNIX boxes...

(It was written for HP-UX 8.02)

Lee Hollingworth
[e-mail]

#include <unistd.h>     // read()
#include <fcntl.h>      // setting keyboard flags
#include <sys/ioctl.h>
#include <termio.h>     // used to set terminal modes
#include <termios.h>

//
// two global variables for tty and keybrd control
//
static struct termio term_orig;
static int kbdflgs;

//
// function :   system_mode
// purpose  :   reset the system to what it was before input_mode was
//              called
//
void system_mode(void)
{
    if (ioctl(0, TCSETA, &term_orig) == -1) {
        return;
    }
    fcntl(0, F_SETFL, kbdflgs);
}

//
// function :   input_mode
// purpose  :   set the system into raw mode for keyboard i/o
// returns  :   0 - error
//              1 - no error
//
int input_mode(void)
{
    struct termio term;    // to avoid ^S ^Q processing

    //
    // get rid of XON/XOFF handling, echo, and other input processing
    //
    if (ioctl(0, TCGETA, &term) == -1) {
        return (0);
    }
    (void) ioctl(0, TCGETA, &term_orig);
    term.c_iflag = 0;
    term.c_oflag = 0;
    term.c_lflag = 0;
    term.c_cc[VMIN] = 1;
    term.c_cc[VTIME] = 0;
    if (ioctl(0, TCSETA, &term) == -1) {
        return (0);
    }
    kbdflgs = fcntl(0, F_GETFL, 0);
    //
    // no delay on reading stdin
    //
    int flags = fcntl(0, F_GETFL);
    flags &= ~O_NDELAY;
    fcntl(0, F_SETFL, flags);
    return (1);
}

//
// function :   getch
// purpose  :   read a single character from the keyboard without echo
// returns  :   the keybress character
//
int getch(void)
{
    //
    // no delays on reading stdin
    //
    input_mode();
    //
    // do a simple loop and get the response
    //
    unsigned char ch;
    while (read(0, &ch, 1) != 1) ;

    system_mode();
    return (ch);
}

int main()
{
    return (getch());
}


Article 32001 of comp.unix.programmer:
Path: mdisea!mmddvan!vanbc.wimsey.com!io.org!interlog.com!usenet.eel.ufl.edu!news.mathworks.com!uunet!in1.uu.net!spcuna!colcig3.colciencias.gov.co!calvin.univalle.edu.co!jmm
From: [e-mail] (Jorge A. Mejia M.)
Newsgroups: comp.unix.programmer
Subject: Re: unix c problemz.
Date: 2 Aug 1995 18:22:45 GMT
Organization: Universidad del Valle
Lines: 77
Message-ID: <3vofpl$[e-mail]>
References: <3vn4vl$[e-mail]>
NNTP-Posting-Host: cusiana.univalle.edu.co
X-Newsreader: TIN [version 1.2 PL2]

Cerridwyn Llewyellyn ([e-mail]) wrote:
: hi:  i'm just beginning to learn unix c programming after years of dos.
: i'm for some reason having large quantities of trouble doing a seemingly 
: simple task:  i want a while loop that executes a command continuously 
: until a key (any key) is presssed:

: while (!keypressed) {
: 	do_something();
: }

: simple, eh?  well, in dos, the appropriate function is kbhit(), but i 
: can't find any such thing in unix... if anyone could send a bit of 
: example code on how to do what i'm doing, i'd worship you forever. please 
: mail to [e-mail].  thanx kindly...

Newsgroups: comp.unix.programmer
Path: calvin.univalle.edu.co!colcig3.colciencias.gov.co!news.new-york.net!spcuna!solaris.cc.vt.edu!news.alpha.net!news.mathworks.com!europa.chnt.gtegsc.com!howland.reston.ans.net!swrinde!elroy.jpl.nasa.gov!llyene!news
From: [e-mail] (Randy Reed)
Subject: Re: Unix C programmers, please help!
Message-ID: <[e-mail]>
Sender: [e-mail]
Reply-To: [e-mail]
Organization: The Unconfigured xvnews people
References: <3uinii$elg@eng_ser1.erg.cuhk.hk>
Date: Thu, 20 Jul 1995 16:51:43 GMT
Lines: 34


I have been annoyed since the inception of the C language that an asynchronous
keyboard routine was not part of the standard library.  Anyway, I have been 
using this version on unix for several years and it seems to do the job. 

#include <stdio.h>
#include <stdlib.h>
#include <sys/time.h>
#include <sys/ioctl.h>
#include <sgtty.h>

#define TTY_DESCR 0
/*===============================================================
 ROUTINE: kbhit
 PURPOSE: Use select to see if a key has been pressed.
 RETURNS: 0 If no key has been hit.
          1 If a key has been pressed.
================================================================*/
int kbhit()
{
    struct timeval wait;
    int readfd,ret;
    int zero=0;

    wait.tv_sec  = 0;
    wait.tv_usec = 0;
    readfd = 1 << TTY_DESCR;
    ret = select(TTY_DESCR + 1, &readfd, &zero, &zero, &wait);
    return(ret);
}


 




--
********************************
*                              *	   
*      Jorge A. Mejia M.       *
* Observatorio Sismologico del *
*     Suroccidente - OSSO      *
*    Universidad del Valle     *
*      Ap. Aereo 25360         *
*      Cali - Colombia         *
*                              *
*   [e-mail]   *
*                              *	   
********************************


-- 
[e-mail] (Bill Mitchell)