docs » hs.ipc

Provides Hammerspoon with the ability to create both local and remote message ports for inter-process communication.

The most common use of this module is to provide support for the command line tool hs which can be added to your terminal shell environment with hs.ipc.cliInstall. The command line tool will not work unless the hs.ipc module is loaded first, so it is recommended that you add require("hs.ipc") to your Hammerspoon init.lua file (usually located at ~/.hammerspoon/init.lua) so that it is always available when Hammerspoon is running.

This module is based heavily on code from Mjolnir by Steven Degutis.

API Overview

Deprecateds - API features which will be removed in an future release

cliGetColors
cliResetColors
cliSetColors

Functions - API calls offered directly by the extension

cliColors
cliInstall
cliSaveHistory
cliSaveHistorySize
cliStatus
cliUninstall

Constructors - API calls which return an object, typically one that offers API methods

localPort
remotePort

Methods - API calls which can only be made on an object returned by a constructor

delete
isRemote
isValid
name
sendMessage

API Documentation

Deprecateds

cliGetColors

Signature	`hs.ipc.cliGetColors() -> table`
Type	Deprecated
Description	See [hs.ipc.cliColors](#cliColors).
Source	extensions/ipc/init.lua

cliResetColors

Signature	`hs.ipc.cliResetColors()`
Type	Deprecated
Description	See [hs.ipc.cliColors](#cliColors).
Source	extensions/ipc/init.lua

cliSetColors

Signature	`hs.ipc.cliSetColors(table) -> table`
Type	Deprecated
Description	See [hs.ipc.cliColors](#cliColors).
Source	extensions/ipc/init.lua

Functions

cliColors

Signature	`hs.ipc.cliColors([colors]) -> table`
Type	Function
Description	Get or set the terminal escape codes used to produce colorized output in the `hs` command line tool
Parameters	colors - an optional table or explicit nil specifying the colors to use when colorizing output for the command line tool. If you specify an explicit nil, the colors will revert to their defaults. If you specify a table it must contain one or more of the following keys with the terminal key sequence as a string for the value: initial - this color is used for the initial tagline when starting the command line tool and for output to the Hammerspoon console that is redirected to the instance. Defaults to "\27[35m" (foreground magenta). input - this color is used for input typed in by the user into the cli instance. Defaults to "\27[33m" (foreground yellow). output - this color is used for output generated by the commands executed within the instance and the results returned. Defaults to "\27[36m" (foreground cyan). error - this color is used for lua errors generated by the commands executed within the instance. Defaults to "\27[31m" (foreground red).
Returns	a table describing the colors used when colorizing output in the `hs` command line tool.
Notes	For a brief intro into terminal colors, you can visit a web site like this one http://jafrog.com/2013/11/23/colors-in-terminal.html Lua doesn't support octal escapes in it's strings, so use `\x1b` or `\27` to indicate the `escape` character e.g. `ipc.cliSetColors{ initial = "", input = "\27[33m", output = "\27[38;5;11m" }`
Source	extensions/ipc/init.lua

cliInstall

Signature	`hs.ipc.cliInstall([path][,silent]) -> bool`
Type	Function
Description	Installs the `hs` command line tool
Parameters	path - An optional string containing a path to install the tool in. Defaults to `/usr/local` silent - An optional boolean indicating whether or not to print errors to the Hammerspoon Console
Returns	A boolean, true if the tool was successfully installed, otherwise false
Notes	If this function fails, it is likely that you have some old/broken symlinks. You can use `hs.ipc.cliUninstall()` to forcibly tidy them up
Source	extensions/ipc/init.lua

cliSaveHistory

Signature	`hs.ipc.cliSaveHistory([state]) -> boolean`
Type	Function
Description	Get or set whether or not the command line tool saves a history of the commands you type.
Parameters	state - an optional boolean (default false) specifying whether or not a history of the commands you type into the command line tool should be saved between sessions.
Returns	the current, possibly changed, value
Notes	If this is enabled, your history is saved in `hs.configDir .. ".cli.history"`, which is usually "~/.hammerspoon/.cli.history". If you have multiple invocations of the command line tool running at the same time, only the history of the last one cleanly exited is saved; this is a limitation of the readline wrapper Apple has provided for libedit and at present no workaround is known.
Source	extensions/ipc/init.lua

cliSaveHistorySize

Signature	`hs.ipc.cliSaveHistorySize([size]) -> number`
Type	Function
Description	Get or set whether the maximum number of commands saved when command line tool history saving is enabled.
Parameters	size - an optional integer (default 1000) specifying the maximum number of commands to save when hs.ipc.cliSaveHistory is set to true.
Returns	the current, possibly changed, value
Notes	When hs.ipc.cliSaveHistory is enabled, your history is saved in `hs.configDir .. ".cli.history"`, which is usually "~/.hammerspoon/.cli.history". If you have multiple invocations of the command line tool running at the same time, only the history of the last one cleanly exited is saved; this is a limitation of the readline wrapper Apple has provided for libedit and at present no workaround is known.
Source	extensions/ipc/init.lua

cliStatus

Signature	`hs.ipc.cliStatus([path][,silent]) -> bool`
Type	Function
Description	Gets the status of the `hs` command line tool
Parameters	path - An optional string containing a path to look for the `hs` tool. Defaults to `/usr/local` silent - An optional boolean indicating whether or not to print errors to the Hammerspoon Console
Returns	A boolean, true if the `hs` command line tool is correctly installed, otherwise false
Source	extensions/ipc/init.lua

cliUninstall

Signature	`hs.ipc.cliUninstall([path][,silent]) -> bool`
Type	Function
Description	Uninstalls the `hs` command line tool
Parameters	path - An optional string containing a path to remove the tool from. Defaults to `/usr/local` silent - An optional boolean indicating whether or not to print errors to the Hammerspoon Console
Returns	A boolean, true if the tool was successfully removed, otherwise false
Notes	This function used to be very conservative and refuse to remove symlinks it wasn't sure about, but now it will unconditionally remove whatever it finds at `path/bin/hs` and `path/share/man/man1/hs.1`. This is more likely to be useful in situations where this command is actually needed (please open an Issue on GitHub if you disagree!)
Source	extensions/ipc/init.lua

Constructors

localPort

Signature	`hs.ipc.localPort(name, fn) -> ipcObject`
Type	Constructor
Description	Create a new local ipcObject for receiving and responding to messages from a remote port
Parameters	name - a string acting as the message port name. fn - the callback function which will receive messages.
Returns	the ipc object
Notes	a remote port can send messages at any time to a local port; a local port can only respond to messages from a remote port
Source	extensions/ipc/internal.m

remotePort

Signature	`hs.ipc.remotePort(name) -> ipcObject`
Type	Constructor
Description	Create a new remote ipcObject for sending messages asynchronously to a local port
Parameters	name - a string acting as the message port name.
Returns	the ipc object
Notes	a remote port can send messages at any time to a local port; a local port can only respond to messages from a remote port
Source	extensions/ipc/internal.m

Methods

delete

Signature	`hs.ipc:delete() -> None`
Type	Method
Description	Deletes the ipcObject, stopping it as well if necessary
Parameters	None
Returns	None
Source	extensions/ipc/internal.m

isRemote

Signature	`hs.ipc:isRemote() -> boolean`
Type	Method
Description	Returns whether or not the ipcObject represents a remote or local port
Parameters	None
Returns	true if the object is a remote port, otherwise false
Notes	a remote port can send messages at any time to a local port; a local port can only respond to messages from a remote port
Source	extensions/ipc/internal.m

isValid

Signature	`hs.ipc:isValid() -> boolean`
Type	Method
Description	Returns whether or not the ipcObject port is still valid or not
Parameters	None
Returns	true if the object is a valid port, otherwise false
Source	extensions/ipc/internal.m

name

Signature	`hs.ipc:name() -> string`
Type	Method
Description	Returns the name the ipcObject uses for its port when active
Parameters	None
Returns	the port name as a string
Source	extensions/ipc/internal.m

sendMessage

Signature	`hs.ipc:sendMessage(data, msgID, [waitTimeout], [oneWay]) -> status, response`
Type	Method
Description	Sends a message from a remote port to a local port
Parameters	data - any data type which is to be sent to the local port. The data will be converted into its string representation msgID - an integer message ID waitTimeout - an optional number, default 2.0, representing the number of seconds the method will wait to send the message and then wait for a response. The method may block up to twice this number of seconds, though usually it will be shorter. oneWay - an optional boolean, default false, indicating whether or not to wait for a response. It this is true, the second returned argument will be nil.
Returns	status - a boolean indicathing whether or not the local port responded before the timeout (true) or if an error or timeout occurred waiting for the response (false) response - the response from the local port, usually a string, but may be nil if there was no response returned. If status is false, will contain an error message describing the error.
Source	extensions/ipc/internal.m