mirrors/emacs
1
Fork 0
mirror of git://git.sv.gnu.org/emacs.git synced 2026-01-11 05:51:21 -08:00
Code Issues Projects Releases Wiki Activity

(Easy Customization): Defn of "User Option" now

Browse source 
includes faces.  Don't say just "option" when talking about variables.
Do say just "options" to mean "anything customizable".
(Specific Customization): Describe `customize-variable',
not `customize-option'.
This commit is contained in:
Richard M. Stallman 2005-01-30 11:34:58 +00:00
parent 12e737f868
commit 89fa0de4cd
1 changed files with 81 additions and 79 deletions
Download patch file Download diff file Expand all files Collapse all files

160
man/custom.texi
View file

@ -178,10 +178,11 @@ region highlighted (currently only when using X). @xref{Mark}.
@cindex user option
Emacs has many @dfn{user options} which have values that you can set
in order to customize various commands. Most user options are
documented in this manual. Each user option is actually a Lisp
variable (@pxref{Variables}), so their names appear in the Variable
Index (@pxref{Variable Index}).
in order to customize various commands. Many user options are
documented in this manual. Most user options are actually Lisp
variables (@pxref{Variables}), so their names appear in the Variable
Index (@pxref{Variable Index}). The rest are faces and their
attributes (@pxref{Faces}).
@findex customize
@cindex customization buffer
@ -203,7 +204,7 @@ the active fields and other features.
* Saving Customizations:: Details of saving customizations.
* Face Customization:: How to edit the attributes of a face.
* Specific Customization:: Making a customization buffer for specific
options, faces, or groups.
variables, faces, or groups.
@end menu
@node Customization Groups
@ -266,7 +267,7 @@ link to another group.
mainly it contains other groups, which contain more groups, which
contain the user options. By browsing the hierarchy of groups, you
will eventually find the feature you are interested in customizing.
Then you can use the customization buffer to set the options and faces
Then you can use the customization buffer to set the options
pertaining to that feature. You can also go straight to a particular
group by name, using the command @kbd{M-x customize-group}.
@ -274,45 +275,45 @@ group by name, using the command @kbd{M-x customize-group}.
You can view the structure of customization groups on a larger scale
with @kbd{M-x customize-browse}. This command creates a special kind of
customization buffer which shows only the names of the groups (and
options and faces), and their structure.
variables and faces), and their structure.
In this buffer, you can show the contents of a group by invoking
@samp{[+]}. When the group contents are visible, this button changes to
@samp{[-]}; invoking that hides the group contents.
Each group, option or face name in this buffer has an active field
which says @samp{[Group]}, @samp{[Option]} or @samp{[Face]}. Invoking
Each group, variable, or face name in this buffer has an active field
which says @samp{[Group]}, @samp{[Variable]} or @samp{[Face]}. Invoking
that active field creates an ordinary customization buffer showing just
that group and its contents, just that option, or just that face.
that group and its contents, just that variable, or just that face.
This is the way to set values in it.
@node Changing an Option
@subsection Changing an Option
@node Changing a Variable
@subsection Changing a Variable
Here is an example of what a user option looks like in the
Here is an example of what a variable looks like in the
customization buffer:
@smallexample
Kill Ring Max: [Hide] 60
[State]: this option is unchanged from its standard setting.
[State]: this variable is unchanged from its standard setting.
Maximum length of kill ring before oldest elements are thrown away.
@end smallexample
The text following @samp{[Hide]}, @samp{60} in this case, indicates
the current value of the option. If you see @samp{[Show]} instead of
the current value of the variable. If you see @samp{[Show]} instead of
@samp{[Hide]}, it means that the value is hidden; the customization
buffer initially hides values that take up several lines. Invoke
@samp{[Show]} to show the value.
The line after the option name indicates the @dfn{customization state}
of the option: in the example above, it says you have not changed the
of the variable: in the example above, it says you have not changed the
option yet. The word @samp{[State]} at the beginning of this line is
active; you can get a menu of various operations by invoking it with
@kbd{Mouse-1} or @key{RET}. These operations are essential for
customizing the user option.
customizing the variable.
The line after the @samp{[State]} line displays the beginning of the
option's documentation string. If there are more lines of
variable's documentation string. If there are more lines of
documentation, this line ends with @samp{[More]}; invoke this to show
the full documentation string.
@ -324,22 +325,22 @@ another number.
change to say that you have edited the value:
@smallexample
[State]: you have edited the value as text, but not set the option.
[State]: you have edited the value as text, but not set the variable.
@end smallexample
@cindex setting option value
Editing the value does not actually set the option. To do
that, you must @dfn{set} the option. To do this, invoke the word
Editing the value does not actually set the variable. To do
that, you must @dfn{set} it. To do this, invoke the word
@samp{[State]} and choose @samp{Set for Current Session}.
The state of the option changes visibly when you set it:
The state of the variable changes visibly when you set it:
@smallexample
[State]: you have set this option, but not saved it for future sessions.
[State]: you have set this variable, but not saved it for future sessions.
@end smallexample
You don't have to worry about specifying a value that is not valid;
setting the option checks for validity and will not really install an
setting the variable checks for validity and will not really install an
unacceptable value.
@kindex M-TAB @r{(customization buffer)}
@ -348,15 +349,15 @@ unacceptable value.
command name, or anything else for which completion is defined, you can
type @kbd{M-@key{TAB}} (@code{widget-complete}) to do completion.
Some options have a small fixed set of possible legitimate values.
These options don't let you edit the value textually. Instead, an
Some variables have a small fixed set of possible legitimate values.
These variables don't let you edit the value textually. Instead, an
active field @samp{[Value Menu]} appears before the value; invoke this
field to edit the value. For a boolean ``on or off'' value, the active
field says @samp{[Toggle]}, and it changes to the other value.
@samp{[Value Menu]} and @samp{[Toggle]} edit the buffer; the changes
take effect when you use the @samp{Set for Current Session} operation.
Some options have values with complex structure. For example, the
Some variables have values with complex structure. For example, the
value of @code{file-coding-system-alist} is an association list. Here
is how it appears in the customization buffer:
@ -379,7 +380,7 @@ File Coding System Alist: [Hide]
Decoding: undecided
Encoding: nil
[INS]
[State]: this option is unchanged from its standard setting.
[State]: this variable is unchanged from its standard setting.
Alist to decide a coding system to use for a file I/O operation. [Hide]
The format is ((PATTERN . VAL) ...),
where PATTERN is a regular expression matching a file name,
@ -415,37 +416,37 @@ previous active or editable field.
when they are finished editing a field. To insert a newline within an
editable field, use @kbd{C-o} or @kbd{C-q C-j}.
@cindex saving option value
@cindex customized options, saving
Setting the option changes its value in the current Emacs session;
@cindex saving variable value
@cindex customized variables, saving
Setting the variable changes its value in the current Emacs session;
@dfn{saving} the value changes it for future sessions as well. To
save the option, invoke @samp{[State]} and select the @samp{Save for
save the variable, invoke @samp{[State]} and select the @samp{Save for
Future Sessions} operation. This works by writing code so as to set
the option again, each time you start Emacs (@pxref{Saving
the variable again, each time you start Emacs (@pxref{Saving
Customizations}).
You can also restore the option to its standard value by invoking
You can also restore the variable to its standard value by invoking
@samp{[State]} and selecting the @samp{Erase Customization} operation.
There are actually three reset operations:
@table @samp
@item Reset
If you have made some modifications and not yet set the option,
If you have made some modifications and not yet set the variable,
this restores the text in the customization buffer to match
the actual value.
@item Reset to Saved
This restores the value of the option to the last saved value,
This restores the value of the variable to the last saved value,
and updates the text accordingly.
@item Erase Customization
This sets the option to its standard value, and updates the text
This sets the variable to its standard value, and updates the text
accordingly. This also eliminates any saved value for the option,
so that you will get the standard value in future Emacs sessions.
@item Use Backup Value
This sets the option to a previous value that was set in the
customization buffer in this session. If you customize an option
This sets the variable to a previous value that was set in the
customization buffer in this session. If you customize a variable
and then reset it, which discards the customized value,
you can get the customized value back again with this operation.
@end table
@ -455,7 +456,7 @@ you can get the customized value back again with this operation.
customization. Use the @samp{Add Comment} item from the
@samp{[State]} menu to create a field for entering the comment. The
comment you enter will be saved, and displayed again if you again view
the same option in a customization buffer, even in another session.
the same variable in a customization buffer, even in another session.
The state of a group indicates whether anything in that group has been
edited, set or saved. You can select @samp{Set for Current Session},
@ -477,8 +478,9 @@ Invoking @samp{[Finish]} either buries or kills this customization
buffer according to the setting of the option
@code{custom-buffer-done-function}; the default is to bury the buffer.
Each of the other fields performs an operation---set, save or
reset---on each of the items in the buffer that could meaningfully be
set, saved or reset.
reset---on each of the options in the buffer that could meaningfully
be set, saved or reset. They do not operate on options whose values
are hidden.
@node Saving Customizations
@subsection Saving Customizations
@ -525,8 +527,8 @@ customizations you might have on your init file.
@cindex italic font
@cindex fonts and faces
In addition to user options, some customization groups also include
faces. When you show the contents of a group, both the user options and
In addition to variables, some customization groups also include
faces. When you show the contents of a group, both the variables and
the faces in the group appear in the customization buffer. Here is an
example of how a face looks:
@ -568,7 +570,7 @@ black-and-white display, the colors you can use for the background are
stipple patterns instead of a color.
Setting, saving and resetting a face work like the same operations for
options (@pxref{Changing an Option}).
variables (@pxref{Changing a Variable}).
A face can specify different appearances for different types of
display. For example, a face can make text red on a color display, but
@ -588,37 +590,37 @@ to clear out the attribute.
@subsection Customizing Specific Items
Instead of finding the options you want to change by moving down
through the structure of groups, you can specify the particular option,
face or group that you want to customize.
through the structure of groups, you can specify the particular variable,
face, or group that you want to customize.
@table @kbd
@item M-x customize-option @key{RET} @var{option} @key{RET}
Set up a customization buffer with just one option, @var{option}.
@item M-x customize-variable @key{RET} @var{variable} @key{RET}
Set up a customization buffer with just one variable, @var{variable}.
@item M-x customize-face @key{RET} @var{face} @key{RET}
Set up a customization buffer with just one face, @var{face}.
@item M-x customize-group @key{RET} @var{group} @key{RET}
Set up a customization buffer with just one group, @var{group}.
@item M-x customize-apropos @key{RET} @var{regexp} @key{RET}
Set up a customization buffer with all the options, faces and groups
Set up a customization buffer with all the variables, faces and groups
that match @var{regexp}.
@item M-x customize-changed-options @key{RET} @var{version} @key{RET}
Set up a customization buffer with all the options, faces and groups
Set up a customization buffer with all the variables, faces and groups
whose meaning has changed since Emacs version @var{version}.
@item M-x customize-saved
Set up a customization buffer containing all options and faces that you
Set up a customization buffer containing all variables and faces that you
have saved with customization buffers.
@item M-x customize-customized
Set up a customization buffer containing all options and faces that you
Set up a customization buffer containing all variables and faces that you
have customized but not saved.
@end table
@findex customize-option
If you want to alter a particular user option with the
customization buffer, and you know its name, you can use the command
@kbd{M-x customize-option} and specify the option name. This sets up
the customization buffer with just one option---the one that you asked
for. Editing, setting and saving the value work as described above, but
only for the specified option.
@findex customize-variable
If you want to alter a particular variable with the customization
buffer, and you know its name, you can use the command @kbd{M-x
customize-variable} and specify the variable name. This sets up the
customization buffer with just one variable---the one that you asked
for. Editing, setting and saving the value work as described above,
but only for the specified variable.
@findex customize-face
Likewise, you can modify a specific face, chosen by name, using
@ -650,11 +652,11 @@ definitions have been changed since the specified version.
@findex customize-saved
@findex customize-customized
If you change option values and then decide the change was a mistake,
you can use two special commands to revisit your previous changes. Use
@kbd{M-x customize-saved} to look at the options and faces that you have
saved. Use @kbd{M-x customize-customized} to look at the options and
faces that you have set but not saved.
If you change option values and then decide the change was a
mistake, you can use two special commands to revisit your previous
changes. Use @kbd{M-x customize-saved} to look at the options that
you have saved. Use @kbd{M-x customize-customized} to look at the
options that you have set but not saved.
@node Variables
@section Variables
@ -679,14 +681,14 @@ turn on the feature---since you have to pick one particular value when you
set the variable---is @code{t}.
Emacs uses many Lisp variables for internal record keeping, but the
most interesting variables for a non-programmer user are the @dfn{user
options}, the variables that are meant for users to change. Each user
option that you can set with the customization buffer is, in fact, a
Lisp variable. Emacs does not (usually) change the values of these
variables; instead, you set the values, and thereby alter and control
the behavior of certain Emacs commands. Use of the customization
buffer is explained above; here we describe other aspects of Emacs
variables.
most interesting variables for a non-programmer user are those that
are also @dfn{user options}, the variables that are meant for users to
change. Each user option that you can set with the customization
buffer is (if it is not a face) in fact a Lisp variable. Emacs does
not (usually) change the values of these variables; instead, you set
the values, and thereby alter and control the behavior of certain
Emacs commands. Use of the customization buffer is explained above;
here we describe other aspects of Emacs variables.
@menu
* Examining:: Examining or setting one variable's value.
@ -734,10 +736,10 @@ variable is a user option. @kbd{C-h v} is not restricted to user
options; it allows any variable name.
@findex set-variable
The most convenient way to set a specific user option is with @kbd{M-x
set-variable}. This reads the variable name with the minibuffer (with
completion), and then reads a Lisp expression for the new value using
the minibuffer a second time. For example,
The most convenient way to set a specific user option variable is
with @kbd{M-x set-variable}. This reads the variable name with the
minibuffer (with completion), and then reads a Lisp expression for the
new value using the minibuffer a second time. For example,
@example
M-x set-variable @key{RET} fill-column @key{RET} 75 @key{RET}
@ -1092,10 +1094,10 @@ so you can judge.
The @code{eval} ``variable,'' and certain actual variables, create a
special risk; when you visit someone else's file, local variable
specifications for these could affect your Emacs in arbitrary ways.
Therefore, the option @code{enable-local-eval} controls whether Emacs
Therefore, the variable @code{enable-local-eval} controls whether Emacs
processes @code{eval} variables, as well variables with names that end
in @samp{-hook}, @samp{-hooks}, @samp{-function} or @samp{-functions},
and certain other variables. The three possibilities for the option's
and certain other variables. The three possibilities for the variable's
value are @code{t}, @code{nil}, and anything else, just as for
@code{enable-local-variables}. The default is @code{maybe}, which is
neither @code{t} nor @code{nil}, so normally Emacs does ask for