add urlencode API

textcode.h

@@ -1,14 +1,21 @@
 #ifndef TEXTCODE_H
 #define TEXTCODE_H
 
+/* These take len bytes from src and write them in encoded form to
+ * dest (if dest != NULL), returning the number of bytes written. */
 unsigned int fmt_uuencoded(char* dest,const char* src,unsigned int len);
 unsigned int fmt_base64(char* dest,const char* src,unsigned int len);
 unsigned int fmt_quotedprintable(char* dest,const char* src,unsigned int len);
+unsigned int fmt_urlencode(char* dest,const char* src,unsigned int len);
 unsigned int fmt_yenc(char* dest,const char* src,unsigned int len);
 
+/* These read one line from src, decoded it, and write the result to
+ * dest.  The number of decoded bytes is written to destlen.  dest
+ * should be able to hold destlen bytes as a rule of thumb. */
 unsigned int scan_uuencoded(const char *src,char *dest,unsigned int *destlen);
 unsigned int scan_base64(const char *src,char *dest,unsigned int *destlen);
 unsigned int scan_quotedprintable(const char *src,char *dest,unsigned int *destlen);
+unsigned int scan_urlencode(const char *src,char *dest,unsigned int *destlen);
 unsigned int scan_yenc(const char *src,char *dest,unsigned int *destlen);
 
 #endif