Problema con kbhit () [y getch ()] para Linux

Question

while(ch != 'q') 
{
  printf("looping\n");
  sleep(1);
  if(kbhit()) 
   {
    ch = readch();
    printf("you hit %c\n",ch);
   }
}

Este código me da un getch bloqueo () como la funcionalidad. Estoy tratando de utilizar este código para capturar hasta las teclas direccionales.

Agregado: Tratar de capturar los códigos de teclas de flecha hacia arriba me da 3 caracteres 27, 91 y 65. El uso de if / else que estoy tratando de coincidencia de patrones, pero solo me dan 2 caracteres. uno al lado es capturado cuando se pulsa la tecla siguiente.

Quiero capturar palabras llenas usando getchar () mientras siempre en busca de ciertas llaves todo el tiempo (ESC, del etc.).

Answer 1

Este ejemplo podría ayudar a:

raw.c - demostración modo raw

/* Raw mode demo */
/* See exactly what is being transmitted from the terminal. To do this
   we have to be more careful. */

#include <stdio.h>
#include <signal.h>
#include <termios.h>
#include <stdlib.h>
#include <unistd.h>

struct termios oldtermios;

int ttyraw(int fd)
{
    /* Set terminal mode as follows:
       Noncanonical mode - turn off ICANON.
       Turn off signal-generation (ISIG)
        including BREAK character (BRKINT).
       Turn off any possible preprocessing of input (IEXTEN).
       Turn ECHO mode off.
       Disable CR-to-NL mapping on input.
       Disable input parity detection (INPCK).
       Disable stripping of eighth bit on input (ISTRIP).
       Disable flow control (IXON).
       Use eight bit characters (CS8).
       Disable parity checking (PARENB).
       Disable any implementation-dependent output processing (OPOST).
       One byte at a time input (MIN=1, TIME=0).
    */
    struct termios newtermios;
    if(tcgetattr(fd, &oldtermios) < 0)
        return(-1);
    newtermios = oldtermios;

    newtermios.c_lflag &= ~(ECHO | ICANON | IEXTEN | ISIG);
    /* OK, why IEXTEN? If IEXTEN is on, the DISCARD character
       is recognized and is not passed to the process. This 
       character causes output to be suspended until another
       DISCARD is received. The DSUSP character for job control,
       the LNEXT character that removes any special meaning of
       the following character, the REPRINT character, and some
       others are also in this category.
    */

    newtermios.c_iflag &= ~(BRKINT | ICRNL | INPCK | ISTRIP | IXON);
    /* If an input character arrives with the wrong parity, then INPCK
       is checked. If this flag is set, then IGNPAR is checked
       to see if input bytes with parity errors should be ignored.
       If it shouldn't be ignored, then PARMRK determines what
       character sequence the process will actually see.

       When we turn off IXON, the start and stop characters can be read.
    */

    newtermios.c_cflag &= ~(CSIZE | PARENB);
    /* CSIZE is a mask that determines the number of bits per byte.
       PARENB enables parity checking on input and parity generation
       on output.
    */

    newtermios.c_cflag |= CS8;
    /* Set 8 bits per character. */

    newtermios.c_oflag &= ~(OPOST);
    /* This includes things like expanding tabs to spaces. */

    newtermios.c_cc[VMIN] = 1;
    newtermios.c_cc[VTIME] = 0;

    /* You tell me why TCSAFLUSH. */
    if(tcsetattr(fd, TCSAFLUSH, &newtermios) < 0)
        return(-1);
    return(0);
}

int ttyreset(int fd)
{
    if(tcsetattr(fd, TCSAFLUSH, &oldtermios) < 0)
        return(-1);

    return(0);
}

void sigcatch(int sig)
{
    ttyreset(0);
    exit(0);
}

int main()
{
    int i;
    char c;

    /* Catch the most popular signals. */
    if((int) signal(SIGINT,sigcatch) < 0)
    {
        perror("signal");
        exit(1);
    }
    if((int)signal(SIGQUIT,sigcatch) < 0)
    {
        perror("signal");
        exit(1);
    }
    if((int) signal(SIGTERM,sigcatch) < 0)
    {
        perror("signal");
        exit(1);
    }

    /* Set raw mode on stdin. */
    if(ttyraw(0) < 0)
    {
        fprintf(stderr,"Can't go to raw mode.\n");
        exit(1);
    }

    while( (i = read(0, &c, 1)) == 1)
    {
        if( (c &= 255) == 0177) /* ASCII DELETE */
            break;
        printf( "%o\n\r", c);
    }

    if(ttyreset(0) < 0)
    {
        fprintf(stderr, "Cannot reset terminal!\n");
        exit(-1);
    }

    if( i < 0)
    {
        fprintf(stderr,"Read error.\n");
        exit(-1);
    }

    return 0;
}

(retroceso para detener la demo, origen )

Answer 2

No puedo reproducir el problema:

#include <unistd.h> 
#include <stdio.h> 
#include <ctype.h> 

#include "kbhit.h" /* http://linux-sxs.org/programming/kbhit.html */

int main(){
  init_keyboard();
  char ch='x';
  while( ch != 'q' ){
    printf("looping\n");
    sleep(1);
    if( kbhit() ){
      printf("you hit");
      do{
        ch = readch();
        printf(" '%c'(%i)", isprint(ch)?ch:'?', (int)ch );
      }while( kbhit() );
      puts("");
    }
  }
  close_keyboard();
}