CODEWITHSUNDEEP
c
Sorwar Hossain Mostafa
Sorwar Hossain Mostafa

Reputation: 255

how to represent keys in c like(enter,shift,alt,space etc)

l want to know how i can represent keys like enter shift etc in c programming language. is there any binary values for those keys? as i can represent esc key with a help of binary value 27. for example:

    int main()
{
    int x;
    char ch;

    while(1)
    {
        ch=getch();
        if(ch==27)
        {
            printf("esc key pressed");
            break;
        }
        else
        {
            printf("%c key pressed\n",ch);
        }
    }
}

in my program if i press esc it will break. now if i want to break with any other keys like enter, shift, alt how to do it ?

Upvotes: 2

Views: 2157

Answers (2)

Cloud
Cloud

Reputation: 19333

Most of this would be platform dependent. However, some keys can be detected by using the keyboard scan codes and the following example program:

#include<stdio.h>

int main()
{
    int ch;
    int ascii[10];
    int count=1;
    ch=getchar();
    ascii[0]=ch;
    while (1)       //Loop used for storing successive ASCII values
    {
        ascii[count]=getchar();
        if (ascii[count]==10) break;
        count++;
    }
    if (27==ascii[0] && 79==ascii[1] && 80==ascii[2]) printf("F1 is pressed");
    if (27==ascii[0] && 79==ascii[1] && 81==ascii[2]) printf("F2 is pressed");
    if (27==ascii[0] && 79==ascii[1] && 82==ascii[2]) printf("F3 is pressed");
    if (27==ascii[0] && 91==ascii[1] && 72==ascii[2]) printf("HOME key is pressed");
    return 0;
}

If you want a more useful example without having to hit ENTER after each keystroke, you could try disabling input buffering and enabling raw mode.

Upvotes: 2

ryyker
ryyker

Reputation: 23218

I want to know how i can represent keys like enter shift etc in c programming language...

As others have said, this is OS dependent.

This function:

short GetAsyncKeyState(int key);

( For Windows programming ) can be used in conjunction with the following #defines in WinUser.h to determine the current AND recent states of a key: 

#define VK_CLEAR          0x0C
#define VK_RETURN         0x0D //AKA enter

#define VK_SHIFT          0x10 
#define VK_CONTROL        0x11
#define VK_MENU           0x12
#define VK_PAUSE          0x13
#define VK_CAPITAL        0x14

#define VK_KANA           0x15
#define VK_HANGEUL        0x15  /* old name - should be here for compatibility */
#define VK_HANGUL         0x15
#define VK_JUNJA          0x17
#define VK_FINAL          0x18
#define VK_HANJA          0x19
#define VK_KANJI          0x19

#define VK_ESCAPE         0x1B

#define VK_CONVERT        0x1C
#define VK_NONCONVERT     0x1D
#define VK_ACCEPT         0x1E
#define VK_MODECHANGE     0x1F

#define VK_SPACE          0x20
#define VK_PRIOR          0x21
#define VK_NEXT           0x22
#define VK_END            0x23
#define VK_HOME           0x24
#define VK_LEFT           0x25
#define VK_UP             0x26
#define VK_RIGHT          0x27
#define VK_DOWN           0x28
#define VK_SELECT         0x29
#define VK_PRINT          0x2A
#define VK_EXECUTE        0x2B
#define VK_SNAPSHOT       0x2C
#define VK_INSERT         0x2D
#define VK_DELETE         0x2E
#define VK_HELP           0x2F

Upvotes: 1

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