add functions to encode and decode variable length integers in binary

fmt.h

@@ -4,6 +4,8 @@
 
 /* for size_t: */
 #include <stddef.h>
+/* for uint32_t */
+#include <stdint.h>
 /* for time_t: */
 #include <sys/types.h>
 
@@ -88,6 +90,12 @@ size_t fmt_humank(char* dest,unsigned long long l);
 /* "Sun, 06 Nov 1994 08:49:37 GMT" */
 size_t fmt_httpdate(char* dest,time_t t);
 
+#define FMT_UTF8 5
+#define FMT_ASN1LENGTH 17 /* enough space to hold 2^128-1 */
+/* some variable length encodings for integers */
+size_t fmt_utf8(char* dest,uint32_t n);	/* can store 0-0x7fffffff */
+size_t fmt_asn1derlength(char* dest,unsigned long long l);
+
 /* internal functions, may be independently useful */
 char fmt_tohex(char c);
 

scan.h

@@ -73,6 +73,10 @@ size_t scan_noncharsetnskip(const char *in,const char *charset,size_t limit) __p
  */
 size_t scan_httpdate(const char *in,time_t *t) __pure__;
 
+/* some variable length encodings for integers */
+size_t scan_utf8(const char* in,size_t len,uint32_t* n) __pure__;
+size_t scan_asn1derlength(const char* in,size_t len,unsigned long long* n) __pure__;
+
 /* a few internal function that might be useful independently */
 /* convert from hex ASCII, return 0 to 15 for success or -1 for failure */
 int scan_fromhex(unsigned char c);