CODEWITHSUNDEEP
clinuxgetchargetchgetc
Jeegar Patel
Jeegar Patel

Reputation: 27210

What is the equivalent to getch() & getche() in Linux?

I am not able to find the equivalent header file for conio.h in Linux.

Is there any option for getch() & getche() function in Linux?

I want to make a switch case base menu where the user will give his option just by pressing one key & process should be moved ahead. I don't want to let user to press ENTER after pressing his choice.

Upvotes: 87

Views: 155673

Answers (6)

mf_
mf_

Reputation: 625

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

char getch(void)
{
    char buf = 0;
    struct termios old = {0};
    fflush(stdout);
    if(tcgetattr(0, &old) < 0)
        perror("tcsetattr()");
    old.c_lflag &= ~ICANON;
    old.c_lflag &= ~ECHO;
    old.c_cc[VMIN] = 1;
    old.c_cc[VTIME] = 0;
    if(tcsetattr(0, TCSANOW, &old) < 0)
        perror("tcsetattr ICANON");
    if(read(0, &buf, 1) < 0)
        perror("read()");
    old.c_lflag |= ICANON;
    old.c_lflag |= ECHO;
    if(tcsetattr(0, TCSADRAIN, &old) < 0)
        perror("tcsetattr ~ICANON");
    printf("%c\n", buf);
    return buf;
 }

Remove the last printf if you don't want the character to be displayed.

Upvotes: 44

niko
niko

Reputation: 9393

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

static struct termios old, current;

/* Initialize new terminal i/o settings */
void initTermios(int echo) 
{
  tcgetattr(0, &old); /* grab old terminal i/o settings */
  current = old; /* make new settings same as old settings */
  current.c_lflag &= ~ICANON; /* disable buffered i/o */
  if (echo) {
      current.c_lflag |= ECHO; /* set echo mode */
  } else {
      current.c_lflag &= ~ECHO; /* set no echo mode */
  }
  tcsetattr(0, TCSANOW, &current); /* 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);
}

/* Let's test it out */
int main(void) {
  char c;
  printf("(getche example) please type a letter: ");
  c = getche();
  printf("\nYou typed: %c\n", c);
  printf("(getch example) please type a letter...");
  c = getch();
  printf("\nYou typed: %c\n", c);
  return 0;
}

Output:

(getche example) please type a letter: g
You typed: g
(getch example) please type a letter...
You typed: g

Upvotes: 100

ralf htp
ralf htp

Reputation: 9422

As said above getch() is in the ncurses library. ncurses has to be initialized, see i.e. getchar() returns the same value (27) for up and down arrow keys for this

Upvotes: -1

Box Box Box Box
Box Box Box Box

Reputation: 5241

You can use the curses.h library in linux as mentioned in the other answer.

You can install it in Ubuntu by:

sudo apt-get update

sudo apt-get install ncurses-dev

I took the installation part from here.

Upvotes: -1

Fafaman
Fafaman

Reputation: 141

I suggest you use curses.h or ncurses.h these implement keyboard management routines including getch(). You have several options to change the behavior of getch (i.e. wait for keypress or not).

Upvotes: 7

Jan S
Jan S

Reputation: 1837

There is a getch() function in the ncurses library. You can get it by installing the ncurses-dev package.

Upvotes: 4

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