1 <p><a href="http://www.gnu.org/licenses/gpl-3.0.txt"><img src="https://img.shields.io/badge/license-GPL_3-green.svg" alt="License GPL 3" /></a>
2 <a href="http://melpa.org/#/async"><img src="http://melpa.org/packages/async-badge.svg" alt="MELPA" title="" /></a>
3 <a href="http://stable.melpa.org/#/async"><img src="http://stable.melpa.org/packages/async-badge.svg" alt="MELPA Stable" title="" /></a></p>
8 `async.el` is a module for doing asynchronous processing in Emacs.
12 ## Install dired-async
14 Add to your `.emacs.el`:
16 (autoload 'dired-async-mode "dired-async.el" nil t)
19 This will allow you to run asynchronously
20 the dired commands for copying, renaming and symlinking.
21 If you are a [helm](https://github.com/emacs-helm/helm) user, this will allow you
22 to copy, rename etc... asynchronously from [helm](https://github.com/emacs-helm/helm).
23 Note that with [helm](https://github.com/emacs-helm/helm)
24 you can disable this by running the copy, rename etc... commands with a prefix argument.
26 If you don't want to make dired/helm asynchronous disable it with `dired-async-mode`.
30 Users of Debian 9 or later or Ubuntu 16.04 or later may simply `apt-get install elpa-async`.
32 ## Enable asynchronous compilation of your (M)elpa packages
34 By default emacs package.el compile packages in its running emacs session.
35 This is not a problem when installing a new package (which is not actually loaded in current emacs)
36 but it may create errors and bad compilation when upgrading a package (old version of package is already loaded
37 and running in current emacs).
38 You can remedy to this by allowing async to compile your packages asynchronously,
39 (helm and magit actually do this by default,
40 so if you are using these packages they will compile asynchronously)
41 to do this, add to your init file:
43 (async-bytecomp-package-mode 1)
46 You can control which packages will compile async with `async-bytecomp-allowed-packages`.
47 Set it to `'(all)` to be sure you will compile all packages asynchronously.
51 The interface is intended to be very easy to use:
55 async-start START-FUNC FINISH-FUNC
57 Execute START-FUNC (often a lambda) in a subordinate Emacs process. When
58 done, the return value is passed to FINISH-FUNC. Example:
61 ;; What to do in the child process
63 (message "This is a test")
67 ;; What to do when it finishes
69 (message "Async process done, result should be 222: %s" result)))
71 If FINISH-FUNC is `nil` or missing, a future is returned that can be inspected
72 using `async-get`, blocking until the value is ready. Example:
74 (let ((proc (async-start
75 ;; What to do in the child process
77 (message "This is a test")
81 (message "I'm going to do some work here") ;; ....
83 (message "Waiting on async process, result should be 222: %s"
86 If you don't want to use a callback, and you don't care about any return value
87 from the child process, pass the `'ignore` symbol as the second argument (if
88 you don't, and never call `async-get`, it will leave ``*emacs*`` process buffers
93 (delete-file "a remote file on a slow link" nil))
96 Note: Even when FINISH-FUNC is present, a future is still returned except that
97 it yields no value (since the value is passed to FINISH-FUNC). Calling
98 `async-get` on such a future always returns `nil`. It can still be useful,
99 however, as an argument to `async-ready` or `async-wait`.
101 ## async-start-process
103 async-start-process NAME PROGRAM FINISH-FUNC &rest PROGRAM-ARGS
105 Start the executable PROGRAM asynchronously. See `async-start`. PROGRAM is
106 passed PROGRAM-ARGS, calling FINISH-FUNC with the process object when done.
107 If FINISH-FUNC is `nil`, the future object will return the process object when
108 the program is finished. Set DEFAULT-DIRECTORY to change PROGRAM's current
115 Get the value from an asynchronously called function when it is ready. FUTURE is
116 returned by `async-start` or `async-start-process` when its FINISH-FUNC is
123 Query a FUTURE to see if its function's value is ready -- i.e., if no blocking
124 would result from a call to `async-get` on that FUTURE.
130 Wait for FUTURE to become ready.
132 ## async-inject-variables
134 async-inject-variables INCLUDE-REGEXP &optional PREDICATE EXCLUDE-REGEXP
136 Return a `setq` form that replicates part of the calling environment. It sets
137 the value for every variable matching INCLUDE-REGEXP and also PREDICATE. It
138 will not perform injection for any variable matching EXCLUDE-REGEXP (if
139 present). It is intended to be used as follows:
145 (insert ,(buffer-substring-no-properties (point-min) (point-max)))
146 ;; Pass in the variable environment for smtpmail
147 ,(async-inject-variables "\\`\\(smtpmail\\|\\(user-\\)?mail\\)-")