Content-ID Header [MIME Headers]

The Content-ID header is an unique identifier of an entity-body. More...

Defines
#define	MSG_CONTENT_ID_INIT()
	Initializer for an msg_content_id_t structure.
Typedefs
typedef msg_generic_t	msg_content_id_t
	Content-ID Header Structure.
Enumerations
enum	{ msg_content_id_hash }
Functions
msg_content_id_t *	msg_content_id_init (msg_content_id_t x[1])
	Initialize an msg_content_id_t structure.
int	msg_is_content_id (msg_header_t const *header)
	Test if header object is an instance of msg_content_id_t.
msg_content_id_t *	msg_content_id_dup (su_home_t *home, msg_content_id_t const *header)
	Duplicate (deep copy) msg_content_id_t.
msg_content_id_t *	msg_content_id_copy (su_home_t *home, msg_content_id_t const *header)
	Copy an msg_content_id_t header structure.
msg_content_id_t *	msg_content_id_make (su_home_t *home, char const *s)
	Make a header structure msg_content_id_t.
msg_content_id_t *	msg_content_id_format (su_home_t *home, char const *fmt,...)))
	Make a Content-ID header from formatting result.
Variables
msg_parse_f	msg_content_id_d
	Parse a Content-ID header.
msg_print_f	msg_content_id_e
	Print a Content-ID header.
msg_hclass_t	msg_content_id_class []
	Header class for Content-ID header.

---

Detailed Description

The Content-ID header is an unique identifier of an entity-body.

The Content-ID value may be used for uniquely identifying MIME entities in several contexts, particularly for caching data referenced by the message/external-body mechanism. Its syntax is defined in [RFC2045] as follows:

      Content-ID   = "Content-ID" ":" msg-id
      msg-id       = [CFWS] "<" id-left "@" id-right ">" [CFWS]
      id-left      = dot-atom-text / no-fold-quote / obs-id-left
      id-right     = dot-atom-text / no-fold-literal / obs-id-right

---

Define Documentation

#define MSG_CONTENT_ID_INIT

(

)

Initializer for an msg_content_id_t structure.

A static msg_content_id_t structure must be initialized with the MSG_CONTENT_ID_INIT() macro. For instance,

  msg_content_id_t msg_content_id = MSG_CONTENT_ID_INIT;

---

Typedef Documentation

msg_generic_t msg_content_id_t

Content-ID Header Structure.

 typedef struct
 {
   msg_common_t      g_common[1];    // Common fragment info
   msg_content_id_t *g_next;           // Link to next header
   char const       *g_string;       // Header value
 }

---

Enumeration Type Documentation

anonymous enum

Enumerator:

msg_content_id_hash

Hash of Content-ID header.

---

Function Documentation

msg_content_id_t * msg_content_id_copy	(	su_home_t *	home,
		msg_content_id_t const *	header
	)			[inline]

Copy an msg_content_id_t header structure.

The function msg_content_id_copy() copies a header structure header. If the header structure header contains a reference (header->h_next) to a list of headers, all the headers in that list are copied, too. The function uses given memory home to allocate all the memory areas used to copy the header structure header.

Parameters:

	home	memory home used to allocate new structure
	header	pointer to the header structure to be duplicated

When copying, only the header structure and parameter lists attached to it are duplicated. The new header structure retains all the references to the strings within the old header, including the encoding of the old header, if present.

Example

   content_id = msg_content_id_copy(home, msg->msg_content_id);

Returns:

The function msg_content_id_copy() returns a pointer to newly copied header structure, or NULL upon an error.

msg_content_id_t * msg_content_id_dup	(	su_home_t *	home,
		msg_content_id_t const *	header
	)			[inline]

Duplicate (deep copy) msg_content_id_t.

The function msg_content_id_dup() duplicates a header structure header. If the header structure header contains a reference (header->x_next) to a list of headers, all the headers in the list are duplicated, too.

Parameters:

	home	memory home used to allocate new structure
	header	header structure to be duplicated

When duplicating, all parameter lists and non-constant strings attached to the header are copied, too. The function uses given memory home to allocate all the memory areas used to copy the header.

Example

   content_id = msg_content_id_dup(home, msg->msg_content_id);

Returns:

The function msg_content_id_dup() returns a pointer to the newly duplicated msg_content_id_t header structure, or NULL upon an error.

msg_content_id_t * msg_content_id_format	(	su_home_t *	home,
		char const *	fmt,
			...
	)			[inline]

Make a Content-ID header from formatting result.

The function msg_content_id_format() makes a new Content-ID header object using snprintf-formatted result as its value. The function first prints the arguments according to the format fmt specified. Then it allocates a new header structure, and uses the formatting result as the header value.

Parameters:

	home	memory home used to allocate new header structure.
	fmt	string used as a printf()-style format
	...	argument list for format

Note:

This function may be implemented as a macro calling msg_header_format().

Returns:

The function msg_content_id_format() returns a pointer to newly makes header structure, or NULL upon an error.

msg_content_id_t* msg_content_id_init

(

msg_content_id_t

x[1]

)

[inline]

Initialize an msg_content_id_t structure.

An msg_content_id_t structure can be initialized with the msg_content_id_init() function/macro. For instance,

  msg_content_id_t msg_content_id;

  msg_content_id_init(&msg_content_id);

Parameters:

x

pointer to msg_content_id_t structure

msg_content_id_t* msg_content_id_make	(	su_home_t *	home,
		char const *	s
	)			[inline]

Make a header structure msg_content_id_t.

The function msg_content_id_make() makes a new msg_content_id_t header structure. It allocates a new header structure, and decodes the string s as the value of the structure.

Parameters:

	home	memory home used to allocate new header structure.
	s	string to be decoded as value of the new header structure

Note:

This function may be implemented as a macro calling msg_header_make().

Returns:

The function msg_content_id_make() returns a pointer to newly maked msg_content_id_t header structure, or NULL upon an error.

int msg_is_content_id

(

msg_header_t const *

header

)

[inline]

Test if header object is an instance of msg_content_id_t.

The function msg_is_content_id() returns true (nonzero) if the header class is an instance of Content-ID header object and false (zero) otherwise.

Parameters:

header

pointer to the header structure to be tested

Returns:

The function msg_is_content_id() returns true (nonzero) if the header object is an instance of header Content-ID header and false (zero) otherwise.

---

Variable Documentation

msg_hclass_t msg_content_id_class[]

Header class for Content-ID header.

The header class msg_content_id_class defines how a Content-ID header header is parsed and printed. It also contains methods used by message parser and other functions to manipulate the msg_content_id_t header structure.