pub fn extract_header(message: &str, name: &str) -> Option<String>Expand description
Extract a header value from a raw SIP message.
Scans all lines up to the blank line separating headers from the message
body. Header name matching is case-insensitive (RFC 3261 §7.3.5) and
recognizes compact header forms (RFC 3261 §7.3.3): searching for "From"
also matches f:, and searching for "f" also matches From:.
Header folding (continuation lines beginning with SP or HTAB) is unfolded
into a single logical value. When a header appears multiple times, values
are concatenated with , (RFC 3261 §7.3.1).
Returns None if no header with the given name is found.