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| author | Kim F. Storm <storm@cua.dk> | 2006-12-19 15:38:08 +0000 |
|---|---|---|
| committer | Kim F. Storm <storm@cua.dk> | 2006-12-19 15:38:08 +0000 |
| commit | f68903b317e0bbddd03b8e2da1e9afedb2afeb47 (patch) | |
| tree | a62eadd0c40a0cd7497819936efecdf547f44fa9 | |
| parent | 6a7d16fe7a567cb815c915c8e056bce4dab7ef9f (diff) | |
| download | emacs-f68903b317e0bbddd03b8e2da1e9afedb2afeb47.tar.gz | |
(Misc Events): User signals now result in sigusr1
and sigusr2 events which are handled through special-event-map.
(Special Events): User signals and drag-n-drop are special.
| -rw-r--r-- | lispref/commands.texi | 34 |
1 files changed, 27 insertions, 7 deletions
diff --git a/lispref/commands.texi b/lispref/commands.texi index 7188961e344..0f45ddbdd04 100644 --- a/lispref/commands.texi +++ b/lispref/commands.texi @@ -1586,14 +1586,33 @@ The precise meaning of the event parameters and the way these parameters are used to display the help-echo text are described in @ref{Text help-echo}. -@cindex @code{signal usr1} event -@cindex @code{signal usr2} event +@cindex @code{sigusr1} event +@cindex @code{sigusr2} event @cindex user signals -@item signal usr1 -@itemx signal usr2 -These event sequences are generated when the Emacs process receives +@item sigusr1 +@itemx sigusr2 +These events are generated when the Emacs process receives the signals @code{SIGUSR1} and @code{SIGUSR2}. They contain no additional data because signals do not carry additional information. + +To catch a user signal, bind the corresponding event to an interactive +command in the @code{special-event-map} (@pxref{Active Keymaps}). +The command is called with no arguments, and the specific signal event is +available in @code{last-input-event}. For example: + +@example +(defun sigusr-handler () + (interactive) + (message "Caught signal %S" last-input-event)) + +(define-key special-event-map [sigusr1] 'sigusr-handler) +@end example + +To test the signal handler, you can make Emacs send a signal to itself: + +@example +(signal-process (emacs-pid) 'sigusr1) +@end example @end table If one of these events arrives in the middle of a key sequence---that @@ -2634,8 +2653,9 @@ These events do, however, appear in @code{last-input-event} immediately after they are read, and this is the way for the event's definition to find the actual event. -The events types @code{iconify-frame}, @code{make-frame-visible} and -@code{delete-frame} are normally handled in this way. The keymap which +The events types @code{iconify-frame}, @code{make-frame-visible}, +@code{delete-frame}, @code{drag-n-drop}, and user signals like +@code{sigusr1} are normally handled in this way. The keymap which defines how to handle special events---and which events are special---is in the variable @code{special-event-map} (@pxref{Active Keymaps}). |