getchar and putchar

Question

My C code:

int c;
c = getchar();

while (c != EOF) {
    putchar(c);
    c = getchar();
}

Why does this program react like this on inputting

Answer 1

getchar reads the input from input stream which is available only after ENTER key is pressed. till then you see only the echoed result from the console To achieve the result you want you could use something like this

#include 
#include 
#include 

int getCHAR( ) {
    struct termios oldt,
                 newt;
    int            ch;
    tcgetattr( STDIN_FILENO, &oldt );
    newt = oldt;
    newt.c_lflag &= ~( ICANON | ECHO );
    tcsetattr( STDIN_FILENO, TCSANOW, &newt );
    ch = getchar();
    putchar(ch);
    tcsetattr( STDIN_FILENO, TCSANOW, &oldt );
    return ch;
}
void main() {
    int c;
    c = getCHAR();
    while (c != 'b') {
        putchar(c);
        c = getCHAR();
    }
}