Exercise 1.23 - Remove comments from a C program¶

/*  Exercise 1.23
 *
 * Program to remove comments from a C Program.
 *
 * Program should echo quotes and character constants properly
 * C comments do not nest
 *
 */

#include <stdio.h>

void rcomment(int c);

void incomment(void);

void echo_quote(int c);

int main(void) {
    int c, d;

    printf(" To Check /* Quoted String */ \n");

    while ((c = getchar()) != EOF)
        rcomment(c);

    return 0;
}

void rcomment(int c) {
    int d;

    if (c == '/') {
        if ((d = getchar()) == '*')
            incomment();
        else if (d == '/') {
            putchar(c);
            rcomment(d);
        } else {
            putchar(c);
            putchar(d);
        }
    } else if (c == '\'' || c == '"')
        echo_quote(c);
    else
        putchar(c);
}

void incomment() {
    int c, d;

    c = getchar();
    d = getchar();

    while (c != '*' || d != '/') {
        c = d;
        d = getchar();
    }
}

void echo_quote(int c) {
    int d;

    putchar(c);

    while ((d = getchar()) != c) {
        putchar(d);

        if (d == '\\')
            putchar(getchar());
    }
    putchar(d);
}