Add widest_line(), returns widest (display width) of lines in char*

does not (yet) support UTF-8

src/sbbs3/str_util.c

@@ -794,3 +794,25 @@ char* make_newsgroup_name(char* str)
 		str[c] = '_';
 	return str;
 }
+
+size_t widest_line(const char* str)
+{
+	size_t widest = 0;
+	size_t width = 0;
+
+	for (size_t i = 0; str[i] != '\0'; ++i) {
+		if (str[i] == '\n') {
+			if (width > widest)
+				widest = width;
+			width = 0;
+		} else if(str[i] == CTRL_A) {
+			++i;
+			if (str[i] == '\0' || str[i] == 'Z')
+				break;
+		} else if(str[i] != '\r')
+			++width;
+	}
+	if (width > widest)
+		return width;
+	return widest;
+}

src/sbbs3/str_util.h

@@ -67,6 +67,7 @@ DLLEXPORT bool      str_is_ascii(const char*);
 DLLEXPORT char *    utf8_to_cp437_inplace(char* str);
 DLLEXPORT char *    separate_thousands(const char* src, char *dest, size_t maxlen, char sep);
 DLLEXPORT char *    make_newsgroup_name(char* str);
+DLLEXPORT size_t	widest_line(const char* str);
 
 #ifdef __cplusplus
 }