/* The C Programming Language 
	my solution for exercise 1-23

	Parse a .c file and remove all comments */
	
#include <stdio.h>
#include <string.h>

#define MAXFILENAME 256

int main(int argc, char* argv[])
{
	char in_name[MAXFILENAME];
	char out_name[MAXFILENAME];
	char buf, oneAhead;
	
	int openSlash, openStar, closeStar, closeSlash, inComment; 
	
	FILE *fp_in, *fp_out;
	
	openSlash = openStar = closeStar = closeSlash = inComment = 0;
	
	if (argc != 3){
		printf("remove_comments usage:\n\tremove comments [input filename] [output filename]");
		return 1;
	}

	if( strcmp(argv[1],argv[2]) == 0 ){
		printf("remove_comments error:\n\tinput and output file names must be different");
		return 2;
	}
	
	strcpy(in_name, argv[1]);
	strcpy(out_name, argv[2]);
	
	/* Attempt to open our files for reading / writing */
	fp_in = fopen(in_name, "r");
	fp_out = fopen(out_name, "w");
	
	if( fp_in == NULL ){
		printf("remove_comments error:\n\tcould not open %s for reading.", in_name);
		return 3;
	}
	
	if( fp_out == NULL ){
		printf("remove_comments error:\n\tcould not open %s for writing.", out_name);
		return 4;
	}
	
	/* Read a .c file char by char, if we're in a comment don't copy */
	while ((buf = fgetc(fp_in)) != EOF)
		if ( inComment == 0 )
			if ( buf == '/' && (oneAhead = fgetc(fp_in)) == '*' )
				inComment = 1;
			else 
				fputc(buf, fp_out);
		else if ( inComment == 1 )
			if ( buf == '*' && (oneAhead = fgetc(fp_in)) == '/' )
				inComment = 0;
	
	fclose(fp_in);
	fclose(fp_out);
	
	return 0;
}