Added a substring to char* function

src/scanner/substring.c

@@ -24,9 +24,24 @@
 #include "substring.h"
 
 #include <string.h>
+#include <stdio.h>
 
 void sbstrcpy(const struct substring *from, char *to)
 {
 	strncpy(to, from->start, SUBSTRING_LENGTH(*from) - 1);
 	to[SUBSTRING_LENGTH(*from) - 1] = '\0';
 }
+
+char *sbstr2str(const struct substring *sbstr)
+{
+	if (SUBSTRING_LENGTH(*sbstr) > 1024) {
+          fprintf(stderr, "Max substring size of 1024 allowed.\
+Use sbstrcpy() instead.\n");
+		return NULL;
+	}
+
+	static char string[1024];
+	sbstrcpy(sbstr, string);
+
+	return string;
+}

src/scanner/substring.h

@@ -31,4 +31,9 @@ struct substring {
 	char *end;
 };
 
+/* write the contents of `from` to `to`
+ * `to` must have the size of SUBSTRING_LENGTH(from) */
 extern void sbstrcpy(const struct substring *from, char *to);
+/* return a manually allocated string of max size 1024
+ * if the size exceeds the limit, retun null*/
+extern char *sbstr2str(const struct substring *sbstr);