Exercise 1-23 from The C Programming Language by Brian W. Kernighan, Dennis M. Ritchie. Problem statement in gist. And yes, there is a goto in this code. This is an acceptable goto as a normal continue statement will not work due to the scope of the looping. If you still subscribe to religious dogmatism of the evils of a goto, then please refer …

c_comment_removal.c

#include <stdio.h>

/* Write a program to remove all comments from a C program,
   Don't forget to handle quoted strings and character constants
   properly. C Comments do not nest */

main(){
    int first,second ,eatChar,lookAhead,previous;
	first = getchar();
	while((second = getchar()) != EOF){
		if(first == '/')
			if(second == '/'){
				//Delete til the end of the line
				while((eatChar=getchar())!=EOF && eatChar != '\n')
					;
				//Print the newline
				putchar(eatChar);
			}else if(second == '*'){
				//Bit harder, read until the next */
				while((eatChar = getchar()) != EOF){
					if(eatChar == '*'){
						lookAhead = getchar();
						if(lookAhead == '/')
							goto next;
						else if(lookAhead == '*')
							ungetc(first,stdin);
					}
				}
			}

		next:
		if(first == '/' && second =='/')
			;
		else if(first == '/' && second == '*')
			;
		else if(previous == '/' && first == '/')
			;
		else if(previous == '/' && first == '*')
			;
		else
			putchar(first);
		previous=first;
		first=second;
	}
	putchar(first);
	printf("\n");
}

To Run:

$cc c_comment_removal.c
$./a.out < fileToRemoveCCommentsFrom.c > newlyformattedfile.c