Exercise 1.10 - Explicit Tabs, Backslash and Backspaces

Question

Write a Program to copy its input to its output, replacing each tab by t,each backspace by b, and each backslash by \. This makes tabs and backspaces visible in an unambiguous way.

Solution

/**
 * Exercise 1.10 - Write a Program to copy its input to its output,
 * replacing each tab by \t, each backspace by \b, and each backslash by \\.
 * This makes tabs and backspaces visible in an unambiguous way.
 *
 * */

#include <stdio.h>

int main(void) {
    int c;

    while ((c = getchar()) != EOF) {
        if (c == '\t') {
            putchar('\\');
            putchar('t');
        }

        if (c == '\b') {
            putchar('\\');
            putchar('b');
        }

        if (c == '\\') {
            putchar('\\');
            putchar('\\');
        }

        if (c != '\t' && c != '\b' && c != '\\')
            putchar(c);
    }
    return 0;
}

Explanation

If the program encounters a special character like \t (tab) or \b (blank) or \\ (backslash), we explicitly handle that and print a \ , using putchar(’\’) and then the literal character. For rest of the characters we simply putchar that.