Added header function to extract specific value

Cargo.toml

@@ -7,6 +7,9 @@ license = "MIT/Apache-2.0"
 description = "A tiny, safe, speedy, zero-copy HTTP/1.x parser."
 repository = "https://github.com/seanmonstar/httparse"
 
+[dependencies]
+unicase = "1"
+
 [features]
 default = ["std"]
 std = []

src/lib.rs

@@ -15,11 +15,13 @@
 //! intrinsic, and simd, are stabilized in rustc.
 
 #[cfg(feature = "std")] extern crate std as core;
+extern crate unicase;
 
 use core::{fmt, result, str, slice};
-
 use iter::Bytes;
 
+use unicase::UniCase;
+
 mod iter;
 
 macro_rules! next {
@@ -249,6 +251,24 @@ impl<'h, 'b> Request<'h, 'b> {
         }
     }
 
+    /// Extract header value using key. If not found or can't be converted to &str then None else the &str value.
+    pub fn header(&self, key: &str) -> Option<&str> {
+        let value: &str;
+
+        for h in self.headers.iter() {
+            if UniCase(h.name) == UniCase(key) {
+                value = str::from_utf8(h.value).unwrap_or("");
+                if value.is_empty() {
+                    return None;
+                } else {
+                    return Some(value);
+                }
+            }
+        }
+
+        None
+    }
+
     /// Try to parse a buffer of bytes into the Request.
     pub fn parse(&mut self, buf: &'b [u8]) -> Result<usize> {
         let orig_len = buf.len();
@@ -345,7 +365,6 @@ impl<'h, 'b> Response<'h, 'b> {
             _ => return Err(Error::Status),
         }
 
-
         let len = orig_len - bytes.len();
         let headers_len = complete!(parse_headers_iter(&mut self.headers, &mut bytes));
         Ok(Status::Complete(len + headers_len))