How to implement getch() function of C in Linux?

Question

In TurboC++, I can use the getch() function from conio.h. But in Linux, gcc doesn't provide conio.h. How can I get the functionality of getch()?

Answer 1

Try this conio.h file:

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

/* reads from keypress, doesn't echo */
int getch(void)
{
    struct termios oldattr, newattr;
    int ch;
    tcgetattr( STDIN_FILENO, &oldattr );
    newattr = oldattr;
    newattr.c_lflag &= ~( ICANON | ECHO );
    tcsetattr( STDIN_FILENO, TCSANOW, &newattr );
    ch = getchar();
    tcsetattr( STDIN_FILENO, TCSANOW, &oldattr );
    return ch;
}

/* reads from keypress, echoes */
int getche(void)
{
    struct termios oldattr, newattr;
    int ch;
    tcgetattr( STDIN_FILENO, &oldattr );
    newattr = oldattr;
    newattr.c_lflag &= ~( ICANON );
    tcsetattr( STDIN_FILENO, TCSANOW, &newattr );
    ch = getchar();
    tcsetattr( STDIN_FILENO, TCSANOW, &oldattr );
    return ch;
}

You can also use the ncurses library in gcc for some functions similar to conio.h.

Answer 2

If echoing to the screen is not a problem, you could try using getchar() from stdio.h.

Answer 3

Check out curses:

http://en.wikipedia.org/wiki/Curses_%28programming_library%29

Answer 4

getch() seems to be included in curses library.

Answer 5

According to these solution code you must manually use open source code for getch() and getche() function as described the code is as following .

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

static struct termios old, new;

/* Initialize new terminal i/o settings */
void initTermios(int echo) 
{
  tcgetattr(0, &old); /* grab old terminal i/o settings */
  new = old; /* make new settings same as old settings */
  new.c_lflag &= ~ICANON; /* disable buffered i/o */
  new.c_lflag &= echo ? ECHO : ~ECHO; /* set echo mode */
  tcsetattr(0, TCSANOW, &new); /* use these new terminal i/o settings now */
}

/* Restore old terminal i/o settings */
void resetTermios(void) 
{
  tcsetattr(0, TCSANOW, &old);
}

/* Read 1 character - echo defines echo mode */
char getch_(int echo) 
{
  char ch;
  initTermios(echo);
  ch = getchar();
  resetTermios();
  return ch;
}

/* Read 1 character without echo */
char getch(void) 
{
  return getch_(0);
}

/* Read 1 character with echo */
char getche(void) 
{
  return getch_(1);
}

Just put it before your main method of code

Answer 6

You can use getch() equivalent from libcaca:

__extern int caca_conio_getch (void)

Answer 7

If, for any reasons, you can't use curses, try this:

# include <stdio.h>
# include <stdlib.h>
# include <string.h>
# include <ctype.h>
# include <termios.h>

/* get a single char from stdin    */
int getch(void)
{
   struct termios oldattr, newattr;
   int ch;
   tcgetattr(0, &oldattr);
   newattr=oldattr;
   newattr.c_lflag &= ~( ICANON | ECHO );
   tcsetattr( 0, TCSANOW, &newattr);
   ch=getchar();
   tcsetattr(0, TCSANOW, &oldattr);
   return(ch);
}