Thread: A Debtab Program Help

So my program is suppose to try to find to tabs from the input and output it with the tabs replaced it by a set number of spaces. In my case 1 tab = 3 spaces. It works with a single tab. However it seems if I do multiple tabs, it adds additional spaces. Can someone look over my code please? Thank you.

Code:

#include <stdio.h>
#define MAXLINE 1000
#define TAB 3

int getline(char line[]);
void copy(char to[], char from[]);

//prints out a line with tabs replaced by spaces
main(){
	int len; //current line length
    char tabbed[MAXLINE]; //current input line
	char detabbed[MAXLINE]; //detabbed line saved here
	
	len = 0;

	while ((len = getline(tabbed)) > 0){
			copy(detabbed, tabbed);
			printf("%s", detabbed);
		}
		return 0;
	}

//read a line into s, return length
int getline(char s[]){
	int c, i;

	for(i = 0; (c = getchar()) != EOF && c != '\n'; ++i)
		s[i] = c;
	if(c == '\n'){
		s[i] = c;
		++i;
		}
	s[i] = '\0';
	return i;
	}

//copy from into to: assume to is big enough
//replaces all tabs with 3 spaces
void copy(char to[], char from[]){
	int i, i2, tmp;

	i = 0;
	i2 = 0;

	while ((to[i] = from[i2]) != '\0'){
		if (from[i] == '\t'){

			for(tmp = 0; tmp != TAB; ++tmp){ 
				to[i] = ' ';
				++i;
				}

			i = i - 1;
			}

		++i;
		++i2;
		}
	}

I would iterate through the original string, keeping a "state" variable, where the states can be, for example,

1) normal
2) skip tabs

then -

Code:

int i;
int len = strlen(orig);
int state = 1;
for (i = 0; i < len; ++i) {
     switch (state) {
          case 1:
                //copy orig[i] to to[i] if it's not a tab
                //otherwise write 3 spaces, and set state to 2
          case 2:
                //if orig[i] is a tab, ignore, otherwise copy to to[i] and set state to 1
     }
}

Without reading very carefully, this looks suspicious.

Code:

while ((to[i] = from[i2]) != '\0'){
		if (from[i] == '\t'){