Something

static int strip_comments ( char *buf )
{
   enum { NORMAL,
	  SINGLE_QUOTE,
	  DOUBLE_QUOTE
	} state;
    char *cp1;

    cp1 = buf;
    state = NORMAL;
    while ( 1 ) {
	switch ( state ) {
	case NORMAL:
	    if (( *cp1 == '#' ) || ( *cp1 == '\n' ) || ( *cp1 == '\0' )) {
		/* end of the line */
		*cp1 = '\0';
		return 0;
	    } else if ( *cp1 == '\'' ) {
		/* start of a quoted string */
		cp1++;
		state = SINGLE_QUOTE;
	    } else if ( *cp1 == '\"' ) {
		/* start of a quoted string */
		cp1++;
		state = DOUBLE_QUOTE;
	    } else {
		/* normal character */
		cp1++;
	    }
	    break;
	case SINGLE_QUOTE:
	    if (( *cp1 == '\n' ) || ( *cp1 == '\0' )) {
		/* end of the line, unterminated quoted string */
		*cp1 = '\0';
		return -1;
	    } else if ( *cp1 == '\'' ) {
		/* end of quoted string */
		cp1++;
		state = NORMAL;
	    } else {
		/* ordinary character */
		cp1++;
	    }
	    break;
	case DOUBLE_QUOTE:
	    if (( *cp1 == '\n' ) || ( *cp1 == '\0' )) {
		/* end of the line, unterminated quoted string */
		*cp1++ = '\0';
		return -1;
	    } else if ( *cp1 == '\"' ) {
		/* end of quoted string */
		cp1++;
		state = NORMAL;
	    } else {
		/* ordinary character */
		cp1++;
	    }
	    break;
	default:
	    /* should never get here */
	    return -1;
	}
    }
}