The ASCII code value corresponding to the control character of the test keyboard

#include <stdio.h>
#include <termio.h>//terminal operation header File

Char getch (void)
{
struct Termios TM, Tm_old;
int fd = 0, ch;

if (Tcgetattr (FD, &AMP;TM) < 0) {//Save current terminal settings
return-1;
}

Tm_old = TM;
Cfmakeraw (&AMP;TM); Change terminal set to original mode, all input data in this mode is processed in bytes
if (tcsetattr (FD, Tcsanow, &tm) < 0) {//settings after the change
return-1;
}

ch = getchar ();
if (tcsetattr (FD, Tcsanow, &tm_old) < 0) {//Change settings to original appearance
return-1;
}

return (char) ch;
}

int main (void)
{
Char ch;
while (ch = getch ()) = 0x0D && ch! = 0x1B) {
printf ("%x", ch);
}
printf ("\ n");
return 0;
}

The ASCII code value corresponding to the control character of the test keyboard