sip_get_header

- get a SIP header from a message

Synopsis

cc [ flag ... ] file ... -lsip [ library ... ]
#include <sip.h>

const struct sip_header *sip_get_header(sip_msg_t sip_msg, 
     char *header_name, sip_header_t old_header, int *error);

Description

The sip_get_header() function returns the header specified by header_name (long or compact form) from the SIP message sip_msg. If header_name is NULL, the first header in the SIP message is returned. The old_header, if non-null, specifies the starting position in sip_msg from which the search is started. Otherwise, the search begins at the start of the SIP message. For example, to get the first VIA header from the SIP message sip_msg:

via_hdr = sip_get_header(sip_msg, "VIA", NULL, &error);

To get the next VIA header from sip_msg:

via_hdr = sip_get_header(sip_msg, "VIA", via_hdr, &error);

The sip_get_header() function ignores any header that is marked as deleted.

Return Values

On success, the sip_get_header() function returns the queried header. On failure, it returns NULL.

The value of errno is not changed by these calls in the event of an error.

Errors

The following value may be returned:

EINVAL

The header_name specified in the SIP message is not present or has been deleted; or, the header_name is not specified and there are no “un-deleted” headers in the SIP message.

Attributes

See attributes(5) for descriptions of the following attributes:

See Also

libsip(3LIB)