# `uv_pipe_t` — Pipe handle

Pipe handles provide an abstraction over streaming files on Unix (including local domain sockets, pipes, and FIFOs) and named pipes on Windows.

`uv_pipe_t` is a ‘subclass’ of `uv_stream_t`.

## Data types

type uv_pipe_t

  Pipe handle type.

### Public members

int uv_pipe_t.ipc

  Whether this pipe is suitable for handle passing between processes. Only a connected pipe that will be passing the handles should have this flag set, not the listening pipe that uv_accept is called on.

See also

The `uv_stream_t` members also apply.

## API

int uv_pipe_init(uv_loop_t *loop, uv_pipe_t *handle, int ipc)

  Initialize a pipe handle. The ipc argument is a boolean to indicate if this pipe will be used for handle passing between processes (which may change the bytes on the wire). Only a connected pipe that will be passing the handles should have this flag set, not the listening pipe that uv_accept is called on.

int uv_pipe_open(uv_pipe_t *handle, uv_file file)

  Open an existing file descriptor or HANDLE as a pipe.

  Changed in version 1.2.1: the file descriptor is set to non-blocking mode.

  Note

  The passed file descriptor or HANDLE is not checked for its type, but it’s required that it represents a valid pipe.

int uv_pipe_bind(uv_pipe_t *handle, const char *name)

  Bind the pipe to a file path (Unix) or a name (Windows).

  Does not support Linux abstract namespace sockets, unlike `uv_pipe_bind2()`.

  Alias for `uv_pipe_bind2(handle, name, strlen(name), 0)`.

  Note

  Paths on Unix get truncated to `sizeof(sockaddr_un.sun_path)` bytes, typically between 92 and 108 bytes.

int uv_pipe_bind2(uv_pipe_t *handle, const char *name, size_t namelen, unsigned int flags)

  Bind the pipe to a file path (Unix) or a name (Windows).

  `flags` must be zero or `UV_PIPE_NO_TRUNCATE`. Returns `UV_EINVAL` for unsupported flags without performing the bind operation.

  Supports Linux abstract namespace sockets. `namelen` must include the leading nul byte but not the trailing nul byte.

  Added in version 1.46.0.

  Note

  Paths on Unix get truncated to `sizeof(sockaddr_un.sun_path)` bytes, typically between 92 and 108 bytes, unless the `UV_PIPE_NO_TRUNCATE` flag is specified, in which case an `UV_EINVAL` error is returned.

void uv_pipe_connect(uv_connect_t *req, uv_pipe_t *handle, const char *name, uv_connect_cb cb)

  Connect to the Unix domain socket or the Windows named pipe.

  Does not support Linux abstract namespace sockets, unlike `uv_pipe_connect2()`.

  Alias for `uv_pipe_connect2(req, handle, name, strlen(name), 0, cb)`.

  Note

  Paths on Unix get truncated to `sizeof(sockaddr_un.sun_path)` bytes, typically between 92 and 108 bytes.

int uv_pipe_connect2(uv_connect_t *req, uv_pipe_t *handle, const char *name, size_t namelen, unsigned int flags, uv_connect_cb cb)

  Connect to the Unix domain socket or the Windows named pipe.

  `flags` must be zero or `UV_PIPE_NO_TRUNCATE`. Returns `UV_EINVAL` for unsupported flags without performing the connect operation.

  Supports Linux abstract namespace sockets. `namelen` must include the leading nul byte but not the trailing nul byte.

  Added in version 1.46.0.

  Note

  Paths on Unix get truncated to `sizeof(sockaddr_un.sun_path)` bytes, typically between 92 and 108 bytes, unless the `UV_PIPE_NO_TRUNCATE` flag is specified, in which case an `UV_EINVAL` error is returned.

int uv_pipe_getsockname(const uv_pipe_t *handle, char *buffer, size_t *size)

  Get the name of the Unix domain socket or the named pipe.

  A preallocated buffer must be provided. The size parameter holds the length of the buffer and it’s set to the number of bytes written to the buffer on output. If the buffer is not big enough `UV_ENOBUFS` will be returned and len will contain the required size.

  Changed in version 1.3.0: the returned length no longer includes the terminating null byte, and the buffer is not null terminated.

int uv_pipe_getpeername(const uv_pipe_t *handle, char *buffer, size_t *size)

  Get the name of the Unix domain socket or the named pipe to which the handle is connected.

  A preallocated buffer must be provided. The size parameter holds the length of the buffer and it’s set to the number of bytes written to the buffer on output. If the buffer is not big enough `UV_ENOBUFS` will be returned and len will contain the required size.

  Added in version 1.3.0.

void uv_pipe_pending_instances(uv_pipe_t *handle, int count)

  Set the number of pending pipe instance handles when the pipe server is waiting for connections.

  Note

  This setting applies to Windows only.

int uv_pipe_pending_count(uv_pipe_t *handle)

uv_handle_type uv_pipe_pending_type(uv_pipe_t *handle)

  Used to receive handles over IPC pipes.

  First - call `uv_pipe_pending_count()`, if it’s > 0 then initialize a handle of the given type, returned by `uv_pipe_pending_type()` and call `uv_accept(pipe, handle)`.

See also

The `uv_stream_t` API functions also apply.

int uv_pipe_chmod(uv_pipe_t *handle, int flags)

  Alters pipe permissions, allowing it to be accessed from processes run by different users. Makes the pipe writable or readable by all users. Mode can be `UV_WRITABLE`, `UV_READABLE` or `UV_WRITABLE | UV_READABLE`. This function is blocking.

  Added in version 1.16.0.

int uv_pipe(uv_file fds[2], int read_flags, int write_flags)

  Create a pair of connected pipe handles. Data may be written to fds[1] and read from fds[0]. The resulting handles can be passed to uv_pipe_open, used with uv_spawn, or for any other purpose.

  Valid values for flags are:

  > - UV_NONBLOCK_PIPE: Opens the specified socket handle for OVERLAPPED or FIONBIO/O_NONBLOCK I/O usage. This is recommended for handles that will be used by libuv, and not usually recommended otherwise.

  Equivalent to pipe(2) with the O_CLOEXEC flag set.

  Added in version 1.41.0.