Functions Network

Home › Function Finder › Networking

Networking

The functions to look up hosts, connect over TCP and UDP, parse and build URLs, fetch web pages over HTTP and HTTPS, grouped by what you want to do. The From column says what a program needs before it can call one:

• std/<Name>: #import "std/<Name>", then using <Name> to call it by its bare name.

Jump to: Parse, print and classify IP addresses · Look up a host name · Connect to a TCP server · Read and write a TCP connection · Accept TCP connections · Send and receive UDP datagrams · Take a URL apart and build one · Read and build query strings · Find out why a network call failed · Fetch a web page or call a web API · Read a large download as it arrives · Encrypt a connection with TLS · Find out why an HTTP request or TLS handshake failed

Parse, print and classify IP addresses

Function	What it does	From
ParseIp	Parses IPv4 or IPv6 text, with an optional zone, and refuses leading zeros.	std/net
IpAddress	Holds one IPv4 or IPv6 address as a value that can be copied and compared.	std/net
IpAddress.ToString	Returns the address as text, IPv6 in its shortest lower-case form.	std/net
IpAddress.IsLoopback / IsPrivate / IsLinkLocal	Tells whether the address is loopback, private or link-local.	std/net
IpAddress.IsMulticast / IsUnspecified / IsGlobalUnicast	Tells whether the address is multicast, all zeros or an ordinary unicast address.	std/net
IpAddress.IsV4Mapped / Unmap	Recognises an IPv4 address written as IPv6 and turns it back into IPv4.	std/net
Ipv4	Returns the IPv4 address made of four numbers.	std/net
IpFromBytes	Returns the address held in 4 or 16 bytes.	std/net
Loopback	Returns 127.0.0.1, or ::1 when asked for IPv6.	std/net
AnyAddress	Returns 0.0.0.0 or ::, the address that binds every interface.	std/net
SocketAddress	Holds an IP address and a port, printed as 1.2.3.4:80 or [::1]:80.	std/net
ParseSocketAddress	Parses an address and port, with brackets around IPv6.	std/net

Look up a host name

Function	What it does	From
Resolve	Looks up a host name and returns every address it has, each with the given port.	std/net

Connect to a TCP server

Function	What it does	From
TcpStream	Holds one TCP connection, which reads and writes like any stream.	std/net
TcpStream.Connect	Connects to an address and port, giving up after an optional timeout.	std/net
TcpStream.ConnectHost	Looks up a host and connects to the first of its addresses that answers.	std/net

Read and write a TCP connection

Function	What it does	From
TcpStream.SetReadTimeout / SetWriteTimeout	Makes a read or write that waits too long fail with a timeout.	std/net
TcpStream.SetNoDelay	Sends small writes at once instead of gathering them.	std/net
TcpStream.SetKeepAlive	Probes an idle connection so that a dead peer is noticed.	std/net
TcpStream.Shutdown	Tells the peer no more data is coming, so its reads end.	std/net
TcpStream.LocalAddress / PeerAddress	Returns the address and port of this end or of the other end.	std/net
TcpStream.Close	Closes the connection; closing twice is harmless.	std/net

Accept TCP connections

Function	What it does	From
TcpListener	Holds a listening socket that waits for TCP connections.	std/net
TcpListener.Bind	Binds an address and port and starts listening; port 0 picks a free one.	std/net
TcpListener.Accept	Waits for the next connection and opens a TcpStream on it, with an optional timeout.	std/net
TcpListener.LocalAddress	Returns the address and port the listener is bound to.	std/net

Send and receive UDP datagrams

Function	What it does	From
UdpSocket	Holds a socket that sends and receives single datagrams.	std/net
UdpSocket.Bind	Receives datagrams on an address and port.	std/net
UdpSocket.SendTo / ReceiveFrom	Sends a datagram to an address, or waits for one and reports its sender.	std/net
UdpSocket.Connect / Send / Receive	Fixes the other end, then sends and receives without naming it.	std/net
UdpSocket.SetReadTimeout	Makes a receive that waits too long fail with a timeout.	std/net
UdpSocket.SetBroadcast / JoinMulticast	Allows broadcast sends, or receives a multicast group.	std/net

Take a URL apart and build one

Function	What it does	From
ParseUrl	Takes a URL apart into scheme, user, host, port, decoded path, query and fragment.	std/net
Url	Holds a URL as fields that can be read, changed and printed again.	std/net
Url.ToString	Returns the URL as text, escaping each part only as much as it needs.	std/net
Url.Resolve	Makes a relative link absolute against this URL, removing . and .. segments.	std/net
Url.HostPort / EscapedPath	Returns host:port, or the path as it appears in the URL.	std/net

Read and build query strings

Function	What it does	From
Url.Query	Returns the URL's query string parsed into QueryValues.	std/net
ParseQuery	Parses name=value pairs, decoding percent escapes and plus signs.	std/net
QueryValues	Holds query pairs in order, where one name may appear more than once.	std/net
QueryValues.Get / GetAll	Returns the first value of a name, or every value of it.	std/net
QueryValues.Add / SetValue / Remove	Appends a pair, replaces a name's values, or removes a name.	std/net
QueryValues.Encode	Returns the pairs as query text in order, with spaces as plus signs.	std/net

Find out why a network call failed

Function	What it does	From
NetError	Holds why a network call failed: a code, the system's number and a message.	std/net
NetErrorMessage	Returns the fixed English text for a NetErrorCode.	std/net

Fetch a web page or call a web API

Function	What it does	From
Fetch	Fetches a URL with GET on a fresh client and returns the whole response.	std/http
Post	Posts a text body to a URL on a fresh client and returns the whole response.	std/http
Client	Holds the request settings and reuses connections to the same host.	std/http
Client.Fetch	Fetches a URL with GET and returns the whole response.	std/http
Client.Head	Sends a HEAD request and returns the status and headers.	std/http
Client.Post	Posts a text body with its content type and returns the whole response.	std/http
Client.Send	Sends a Request, follows redirects and reads the whole body into a Response.	std/http
Request	Holds a method, URL, headers and body to send.	std/http
Request.SetBody	Sets the body as UTF-8 text and its Content-Type.	std/http
Request.SetBasicAuth	Adds an Authorization: Basic header for a user name and password.	std/http
Response	Holds the status, headers, final URL and body of a reply.	std/http
Response.Text	Returns the body decoded as UTF-8 text.	std/http
Headers	Holds header fields in order, with names compared regardless of case.	std/http

Read a large download as it arrives

Function	What it does	From
Client.Open	Sends a request and hands the body over as a stream to read at your own pace.	std/http
ResponseStream	Reads a response body as a stream and gives the connection back when closed.	std/http

Encrypt a connection with TLS

Function	What it does	From
TlsStream	Encrypts a connected stream with TLS, as a client or a server.	std/tls
TlsStream.ConnectHost	Opens a TCP connection to a host and shakes hands as a TLS client.	std/tls
TlsStream.Connect	Shakes hands as a TLS client over a stream that is already connected.	std/tls
TlsStream.Accept	Shakes hands as a TLS server over an accepted connection.	std/tls
TlsConfig	Holds the TLS version floor, extra trusted roots and a server's certificate and key.	std/tls
TlsConfig.AddRootPem	Trusts the root certificates in PEM text as well as the system's.	std/tls
TlsConfig.SetIdentityPem	Sets a server's certificate chain and PKCS#8 private key from PEM text.	std/tls

Find out why an HTTP request or TLS handshake failed

Function	What it does	From
HttpError	Holds why an HTTP request failed: a code, the URL and the lower layer's message.	std/http
TlsError	Holds why a TLS handshake failed, such as an untrusted or expired certificate.	std/tls

See Also

• Net guide
• HTTP and TLS guide
• Codec guide (percent-encoding)

---

Home · Function Finder · Keyword Index