Problema com kbhit () [e getch ()] para Linux
-
19-09-2019 - |
Pergunta
while(ch != 'q')
{
printf("looping\n");
sleep(1);
if(kbhit())
{
ch = readch();
printf("you hit %c\n",ch);
}
}
Este código dá-me um getch bloqueio () como a funcionalidade. Eu estou tentando usar este código para capturar até para baixo teclas de seta.
Adicionado: Tentando capturar os códigos de chave de seta para cima me dá 3 caracteres 27, 91 e 65. Usando if / else Estou tentando correspondência de padrão, mas eu somente 2 caracteres. Próximo é capturado na próxima tecla é pressionada.
Eu quero capturar palavras cheias usando getchar () enquanto sempre à procura de certas chaves o tempo todo (esc, del etc.).
Solução
Este exemplo poderia ajudar:
raw.c - raw modo de demonstração
/* 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;
}
(backspace para parar a demonstração, origem )
Outras dicas
Eu não posso reproduzir o 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();
}
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