Header struct

The header struct pointer the header API functions return, points to memory associated with the easy handle and subsequent calls to the functions clobber that struct. Applications need to copy the data if they want to keep it around. The memory used for the struct gets freed with calling curl_easy_cleanup().

The struct

struct curl_header {
   char *name;
   char *value;
   size_t amount;
   size_t index;
   unsigned int origin;
   void *anchor;

name is the name of header. It uses the casing used for the first instance of the header with this name.

value is the content. It comes exactly as delivered over the network but with leading and trailing whitespace and newlines stripped off. The data is always null-terminated.

amount is the number of headers using this name that exist, within the asked origin and request context.

index is the zero based entry number of this particular header name, which in case this header was used more than once in the requested scope can be larger than 0 but is always less than amount.

origin has (exactly) one of the origin bits set, indicating where from the header originates.

anchor is a private handle used by libcurl internals. Do not modify. Do not assume anything about it.