This is ../info/xemacs.info, produced by makeinfo version 4.0 from xemacs/xemacs.texi. INFO-DIR-SECTION XEmacs Editor START-INFO-DIR-ENTRY * XEmacs: (xemacs). XEmacs Editor. END-INFO-DIR-ENTRY This file documents the XEmacs editor. Copyright (C) 1985, 1986, 1988 Richard M. Stallman. Copyright (C) 1991, 1992, 1993, 1994 Lucid, Inc. Copyright (C) 1993, 1994 Sun Microsystems, Inc. Copyright (C) 1995 Amdahl Corporation. Permission is granted to make and distribute verbatim copies of this manual provided the copyright notice and this permission notice are preserved on all copies. Permission is granted to copy and distribute modified versions of this manual under the conditions for verbatim copying, provided also that the sections entitled "The GNU Manifesto", "Distribution" and "GNU General Public License" are included exactly as in the original, and provided that the entire resulting derived work is distributed under the terms of a permission notice identical to this one. Permission is granted to copy and distribute translations of this manual into another language, under the above conditions for modified versions, except that the sections entitled "The GNU Manifesto", "Distribution" and "GNU General Public License" may be included in a translation approved by the author instead of in the original English.  File: xemacs.info, Node: Interactive Shell, Next: Shell Mode, Prev: Single Shell, Up: Shell Interactive Inferior Shell -------------------------- To run a subshell interactively with its typescript in an XEmacs buffer, use `M-x shell'. This creates (or reuses) a buffer named `*shell*' and runs a subshell with input coming from and output going to that buffer. That is to say, any "terminal output" from the subshell will go into the buffer, advancing point, and any "terminal input" for the subshell comes from text in the buffer. To give input to the subshell, go to the end of the buffer and type the input, terminated by . XEmacs does not wait for the subshell to do anything. You can switch windows or buffers and edit them while the shell is waiting, or while it is running a command. Output from the subshell waits until XEmacs has time to process it; this happens whenever XEmacs is waiting for keyboard input or for time to elapse. To get multiple subshells, change the name of buffer `*shell*' to something different by using `M-x rename-buffer'. The next use of `M-x shell' creates a new buffer `*shell*' with its own subshell. By renaming this buffer as well you can create a third one, and so on. All the subshells run independently and in parallel. The file name used to load the subshell is the value of the variable `explicit-shell-file-name', if that is non-`nil'. Otherwise, the environment variable `ESHELL' is used, or the environment variable `SHELL' if there is no `ESHELL'. If the file name specified is relative, the directories in the list `exec-path' are searched (*note Single Shell Commands: Single Shell.). As soon as the subshell is started, it is sent as input the contents of the file `~/.emacs_SHELLNAME', if that file exists, where SHELLNAME is the name of the file that the shell was loaded from. For example, if you use `csh', the file sent to it is `~/.emacs_csh'. `cd', `pushd', and `popd' commands given to the inferior shell are watched by XEmacs so it can keep the `*shell*' buffer's default directory the same as the shell's working directory. These commands are recognized syntactically by examining lines of input that are sent. If you use aliases for these commands, you can tell XEmacs to recognize them also. For example, if the value of the variable `shell-pushd-regexp' matches the beginning of a shell command line, that line is regarded as a `pushd' command. Change this variable when you add aliases for `pushd'. Likewise, `shell-popd-regexp' and `shell-cd-regexp' are used to recognize commands with the meaning of `popd' and `cd'. `M-x shell-resync-dirs' queries the shell and resynchronizes XEmacs' idea of what the current directory stack is. `M-x shell-dirtrack-toggle' turns directory tracking on and off. XEmacs keeps a history of the most recent commands you have typed in the `*shell*' buffer. If you are at the beginning of a shell command line and type , the previous shell input is inserted into the buffer before point. Immediately typing again deletes that input and inserts the one before it. By repeating you can move backward through your commands until you find one you want to repeat. You may then edit the command before typing if you wish. moves forward through the command history, in case you moved backward past the one you wanted while using . If you type the first few characters of a previous command and then type , the most recent shell input starting with those characters is inserted. This can be very convenient when you are repeating a sequence of shell commands. The variable `input-ring-size' controls how many commands are saved in your input history. The default is 30.  File: xemacs.info, Node: Shell Mode, Next: Terminal emulator, Prev: Interactive Shell, Up: Shell Shell Mode ---------- The shell buffer uses Shell mode, which defines several special keys attached to the `C-c' prefix. They are chosen to resemble the usual editing and job control characters present in shells that are not under XEmacs, except that you must type `C-c' first. Here is a list of the special key bindings of Shell mode: `' At end of buffer send line as input; otherwise, copy current line to end of buffer and send it (`send-shell-input'). When a line is copied, any text at the beginning of the line that matches the variable `shell-prompt-pattern' is left out; this variable's value should be a regexp string that matches the prompts that you use in your subshell. `C-c C-d' Send end-of-file as input, probably causing the shell or its current subjob to finish (`shell-send-eof'). `C-d' If point is not at the end of the buffer, delete the next character just like most other modes. If point is at the end of the buffer, send end-of-file as input, instead of generating an error as in other modes (`comint-delchar-or-maybe-eof'). `C-c C-u' Kill all text that has yet to be sent as input (`kill-shell-input'). `C-c C-w' Kill a word before point (`backward-kill-word'). `C-c C-c' Interrupt the shell or its current subjob if any (`interrupt-shell-subjob'). `C-c C-z' Stop the shell or its current subjob if any (`stop-shell-subjob'). `C-c C-\' Send quit signal to the shell or its current subjob if any (`quit-shell-subjob'). `C-c C-o' Delete last batch of output from shell (`kill-output-from-shell'). `C-c C-r' Scroll top of last batch of output to top of window (`show-output-from-shell'). `C-c C-y' Copy the previous bunch of shell input and insert it into the buffer before point (`copy-last-shell-input'). No final newline is inserted, and the input copied is not resubmitted until you type . `M-p' Move backward through the input history. Search for a matching command if you have typed the beginning of a command (`comint-previous-input'). `M-n' Move forward through the input history. Useful when you are using quickly and go past the desired command (`comint-next-input'). `' Complete the file name preceding point (`comint-dynamic-complete').  File: xemacs.info, Node: Terminal emulator, Next: Term Mode, Prev: Shell Mode, Up: Shell Interactive Inferior Shell with Terminal Emulator ------------------------------------------------- To run a subshell in a terminal emulator, putting its typescript in an XEmacs buffer, use `M-x term'. This creates (or reuses) a buffer named `*term*' and runs a subshell with input coming from your keyboard and output going to that buffer. All the normal keys that you type are sent without any interpretation by XEmacs directly to the subshell, as "terminal input." Any "echo" of your input is the responsibility of the subshell. (The exception is the terminal escape character, which by default is `C-c'. *note Term Mode::.) Any "terminal output" from the subshell goes into the buffer, advancing point. Some programs (such as XEmacs itself) need to control the appearance on the terminal screen in detail. They do this by sending special control codes. The exact control codes needed vary from terminal to terminal, but nowadays most terminals and terminal emulators (including xterm) understand the so-called "ANSI escape sequences" (first popularized by the Digital's VT100 family of terminal). The term mode also understands these escape sequences, and for each control code does the appropriate thing to change the buffer so that the appearance of the window will match what it would be on a real terminal. Thus you can actually run XEmacs inside an XEmacs Term window! XEmacs does not wait for the subshell to do anything. You can switch windows or buffers and edit them while the shell is waiting, or while it is running a command. Output from the subshell waits until XEmacs has time to process it; this happens whenever XEmacs is waiting for keyboard input or for time to elapse. To make multiple terminal emulators, rename the buffer `*term*' to something different using `M-x rename-uniquely', just as with Shell mode. The file name used to load the subshell is determined the same way as for Shell mode. Unlike Shell mode, Term mode does not track the current directory by examining your input. Instead, if you use a programmable shell, you can have it tell Term what the current directory is. This is done automatically by bash for version 1.15 and later.  File: xemacs.info, Node: Term Mode, Next: Paging in Term, Prev: Terminal emulator, Up: Shell Term Mode --------- Term uses Term mode, which has two input modes: In line mode, Term basically acts like Shell mode. *Note Shell Mode::. In Char mode, each character is sent directly to the inferior subshell, except for the Term escape character, normally `C-c'. To switch between line and char mode, use these commands: findex term-char-mode `C-c C-k' Switch to line mode. Do nothing if already in line mode. `C-c C-j' Switch to char mode. Do nothing if already in char mode. The following commands are only available in Char mode: `C-c C-c' Send a literal to the sub-shell. `C-c C-x' A prefix command to conveniently access the global commands. For example, `C-c C-x o' invokes the global binding of `C-x o', which is normally `other-window'.  File: xemacs.info, Node: Paging in Term, Prev: Term Mode, Up: Shell Paging in the terminal emulator ------------------------------- Term mode has a pager feature. When the pager is enabled, term mode will pause at the end of each screenful. `C-c C-q' Toggles the pager feature: Disables the pager if it is enabled, and vice versa. This works in both line and char modes. If the pager enabled, the mode-line contains the word `page'. If the pager is enabled, and Term receives more than a screenful of output since your last input, Term will enter More break mode. This is indicated by `**MORE**' in the mode-line. Type a `Space' to display the next screenful of output. Type `?' to see your other options. The interface is similar to the Unix `more' program.  File: xemacs.info, Node: Narrowing, Next: Hardcopy, Prev: Shell, Up: Top Narrowing ========= "Narrowing" means focusing in on some portion of the buffer, making the rest temporarily invisible and inaccessible. Cancelling the narrowing and making the entire buffer once again visible is called "widening". The amount of narrowing in effect in a buffer at any time is called the buffer's "restriction". `C-x n n' Narrow down to between point and mark (`narrow-to-region'). `C-x n w' Widen to make the entire buffer visible again (`widen'). Narrowing sometimes makes it easier to concentrate on a single subroutine or paragraph by eliminating clutter. It can also be used to restrict the range of operation of a replace command or repeating keyboard macro. The word `Narrow' appears in the mode line whenever narrowing is in effect. When you have narrowed to a part of the buffer, that part appears to be all there is. You can't see the rest, can't move into it (motion commands won't go outside the visible part), and can't change it in any way. However, the invisible text is not gone; if you save the file, it will be saved. The primary narrowing command is `C-x n n' (`narrow-to-region'). It sets the current buffer's restrictions so that the text in the current region remains visible but all text before the region or after the region is invisible. Point and mark do not change. Because narrowing can easily confuse users who do not understand it, `narrow-to-region' is normally a disabled command. Attempting to use this command asks for confirmation and gives you the option of enabling it; once you enable the command, confirmation will no longer be required. *Note Disabling::. To undo narrowing, use `C-x n w' (`widen'). This makes all text in the buffer accessible again. Use the `C-x =' command to get information on what part of the buffer you narrowed down. *Note Position Info::.  File: xemacs.info, Node: Hardcopy, Next: Recursive Edit, Prev: Narrowing, Up: Top Hardcopy Output =============== The XEmacs commands for making hardcopy derive their names from the Unix commands `print' and `lpr'. `M-x print-buffer' Print hardcopy of current buffer using Unix command `print' (`lpr -p'). This command adds page headings containing the file name and page number. `M-x lpr-buffer' Print hardcopy of current buffer using Unix command `lpr'. This command does not add page headings. `M-x print-region' Like `print-buffer', but prints only the current region. `M-x lpr-region' Like `lpr-buffer', but prints only the current region. All the hardcopy commands pass extra switches to the `lpr' program based on the value of the variable `lpr-switches'. Its value should be a list of strings, each string a switch starting with `-'. For example, the value could be `("-Pfoo")' to print on printer `foo'.  File: xemacs.info, Node: Recursive Edit, Next: Dissociated Press, Prev: Hardcopy, Up: Top Recursive Editing Levels ======================== A "recursive edit" is a situation in which you are using XEmacs commands to perform arbitrary editing while in the middle of another XEmacs command. For example, when you type `C-r' inside a `query-replace', you enter a recursive edit in which you can change the current buffer. When you exit from the recursive edit, you go back to the `query-replace'. "Exiting" a recursive edit means returning to the unfinished command, which continues execution. For example, exiting the recursive edit requested by `C-r' in `query-replace' causes query replacing to resume. Exiting is done with `C-M-c' (`exit-recursive-edit'). You can also "abort" a recursive edit. This is like exiting, but also quits the unfinished command immediately. Use the command `C-]' (`abort-recursive-edit') for this. *Note Quitting::. The mode line shows you when you are in a recursive edit by displaying square brackets around the parentheses that always surround the major and minor mode names. Every window's mode line shows the square brackets, since XEmacs as a whole, rather than any particular buffer, is in a recursive edit. It is possible to be in recursive edits within recursive edits. For example, after typing `C-r' in a `query-replace', you might type a command that entered the debugger. In such a case, two or more sets of square brackets appear in the mode line(s). Exiting the inner recursive edit (here with the debugger `c' command) resumes the query-replace command where it called the debugger. After the end of the query-replace command, you would be able to exit the first recursive edit. Aborting exits only one level of recursive edit; it returns to the command level of the previous recursive edit. You can then abort that one as well. The command `M-x top-level' aborts all levels of recursive edits, returning immediately to the top level command reader. The text you edit inside the recursive edit need not be the same text that you were editing at top level. If the command that invokes the recursive edit selects a different buffer first, that is the buffer you will edit recursively. You can switch buffers within the recursive edit in the normal manner (as long as the buffer-switching keys have not been rebound). While you could theoretically do the rest of your editing inside the recursive edit, including visiting files, this could have surprising effects (such as stack overflow) from time to time. It is best if you always exit or abort a recursive edit when you no longer need it. In general, XEmacs tries to avoid using recursive edits. It is usually preferable to allow users to switch among the possible editing modes in any order they like. With recursive edits, the only way to get to another state is to go "back" to the state that the recursive edit was invoked from.  File: xemacs.info, Node: Dissociated Press, Next: CONX, Prev: Recursive Edit, Up: Top Dissociated Press ================= `M-x dissociated-press' is a command for scrambling a file of text either word by word or character by character. Starting from a buffer of straight English, it produces extremely amusing output. The input comes from the current XEmacs buffer. Dissociated Press writes its output in a buffer named `*Dissociation*', and redisplays that buffer after every couple of lines (approximately) to facilitate reading it. `dissociated-press' asks every so often whether to continue operating. Answer `n' to stop it. You can also stop at any time by typing `C-g'. The dissociation output remains in the `*Dissociation*' buffer for you to copy elsewhere if you wish. Dissociated Press operates by jumping at random from one point in the buffer to another. In order to produce plausible output rather than gibberish, it insists on a certain amount of overlap between the end of one run of consecutive words or characters and the start of the next. That is, if it has just printed out `president' and then decides to jump to a different point in the file, it might spot the `ent' in `pentagon' and continue from there, producing `presidentagon'. Long sample texts produce the best results. A positive argument to `M-x dissociated-press' tells it to operate character by character, and specifies the number of overlap characters. A negative argument tells it to operate word by word and specifies the number of overlap words. In this mode, whole words are treated as the elements to be permuted, rather than characters. No argument is equivalent to an argument of two. For your againformation, the output goes only into the buffer `*Dissociation*'. The buffer you start with is not changed. Dissociated Press produces nearly the same results as a Markov chain based on a frequency table constructed from the sample text. It is, however, an independent, ignoriginal invention. Dissociated Press techniquitously copies several consecutive characters from the sample between random choices, whereas a Markov chain would choose randomly for each word or character. This makes for more plausible sounding results and runs faster. It is a mustatement that too much use of Dissociated Press can be a developediment to your real work. Sometimes to the point of outragedy. And keep dissociwords out of your documentation, if you want it to be well userenced and properbose. Have fun. Your buggestions are welcome.  File: xemacs.info, Node: CONX, Next: Amusements, Prev: Dissociated Press, Up: Top CONX ==== Besides producing a file of scrambled text with Dissociated Press, you can generate random sentences by using CONX. `M-x conx' Generate random sentences in the `*conx*' buffer. `M-x conx-buffer' Absorb the text in the current buffer into the `conx' database. `M-x conx-init' Forget the current word-frequency tree. `M-x conx-load' Load a `conx' database that has been previously saved with `M-x conx-save'. `M-x conx-region' Absorb the text in the current buffer into the `conx' database. `M-x conx-save' Save the current `conx' database to a file for future retrieval. Copy text from a buffer using `M-x conx-buffer' or `M-x conx-region' and then type `M-x conx'. Output is continuously generated until you type <^G>. You can save the `conx' database to a file with `M-x conx-save', which you can retrieve with `M-x conx-load'. To clear the database, use `M-x conx-init'.  File: xemacs.info, Node: Amusements, Next: Emulation, Prev: CONX, Up: Top Other Amusements ================ If you are a little bit bored, you can try `M-x hanoi'. If you are considerably bored, give it a numeric argument. If you are very, very bored, try an argument of 9. Sit back and watch. When you are frustrated, try the famous Eliza program. Just do `M-x doctor'. End each input by typing `RET' twice. When you are feeling strange, type `M-x yow'.  File: xemacs.info, Node: Emulation, Next: Customization, Prev: Amusements, Up: Top Emulation ========= XEmacs can be programmed to emulate (more or less) most other editors. Standard facilities can emulate these: Viper (a vi emulator) In XEmacs, Viper is the preferred emulation of vi within XEmacs. Viper is designed to allow you to take advantage of the best features of XEmacs while still doing your basic editing in a familiar, vi-like fashion. Viper provides various different levels of vi emulation, from a quite complete emulation that allows almost no access to native XEmacs commands, to an "expert" mode that combines the most useful vi commands with the most useful XEmacs commands. To start Viper, put the command (viper-mode) in your init file. *Note Init File::. Viper comes with a separate manual that is provided standard with the XEmacs distribution. EDT (DEC VMS editor) Turn on EDT emulation with `M-x edt-emulation-on'. `M-x edt-emulation-off' restores normal Emacs command bindings. Most of the EDT emulation commands are keypad keys, and most standard Emacs key bindings are still available. The EDT emulation rebindings are done in the global keymap, so there is no problem switching buffers or major modes while in EDT emulation. Gosling Emacs Turn on emulation of Gosling Emacs (aka Unipress Emacs) with `M-x set-gosmacs-bindings'. This redefines many keys, mostly on the `C-x' and `ESC' prefixes, to work as they do in Gosmacs. `M-x set-gnu-bindings' returns to normal XEmacs by rebinding the same keys to the definitions they had at the time `M-x set-gosmacs-bindings' was done. It is also possible to run Mocklisp code written for Gosling Emacs. *Note Mocklisp::.  File: xemacs.info, Node: Customization, Next: Quitting, Prev: Emulation, Up: Top Customization ************* This chapter talks about various topics relevant to adapting the behavior of Emacs in minor ways. All kinds of customization affect only the particular Emacs job that you do them in. They are completely lost when you kill the Emacs job, and have no effect on other Emacs jobs you may run at the same time or later. The only way an Emacs job can affect anything outside of it is by writing a file; in particular, the only way to make a customization `permanent' is to put something in your init file or other appropriate file to do the customization in each session. *Note Init File::. * Menu: * Minor Modes:: Each minor mode is one feature you can turn on independently of any others. * Variables:: Many Emacs commands examine Emacs variables to decide what to do; by setting variables, you can control their functioning. * Keyboard Macros:: A keyboard macro records a sequence of keystrokes to be replayed with a single command. * Key Bindings:: The keymaps say what command each key runs. By changing them, you can "redefine keys". * Syntax:: The syntax table controls how words and expressions are parsed. * Init File:: How to write common customizations in the init file. * Audible Bell:: Changing how Emacs sounds the bell. * Faces:: Changing the fonts and colors of a region of text. * Frame Components:: Controlling the presence and positions of the menubar, toolbars, and gutters. * X Resources:: X resources controlling various aspects of the behavior of XEmacs.  File: xemacs.info, Node: Minor Modes, Next: Variables, Up: Customization Minor Modes =========== Minor modes are options which you can use or not. For example, Auto Fill mode is a minor mode in which breaks lines between words as you type. All the minor modes are independent of each other and of the selected major mode. Most minor modes inform you in the mode line when they are on; for example, `Fill' in the mode line means that Auto Fill mode is on. Append `-mode' to the name of a minor mode to get the name of a command function that turns the mode on or off. Thus, the command to enable or disable Auto Fill mode is called `M-x auto-fill-mode'. These commands are usually invoked with `M-x', but you can bind keys to them if you wish. With no argument, the function turns the mode on if it was off and off if it was on. This is known as "toggling". A positive argument always turns the mode on, and an explicit zero argument or a negative argument always turns it off. Auto Fill mode allows you to enter filled text without breaking lines explicitly. Emacs inserts newlines as necessary to prevent lines from becoming too long. *Note Filling::. Overwrite mode causes ordinary printing characters to replace existing text instead of moving it to the right. For example, if point is in front of the `B' in `FOOBAR', and you type a `G' in Overwrite mode, it changes to `FOOGAR', instead of `FOOGBAR'. Abbrev mode allows you to define abbreviations that automatically expand as you type them. For example, `amd' might expand to `abbrev mode'. *Note Abbrevs::, for full information.  File: xemacs.info, Node: Variables, Next: Keyboard Macros, Prev: Minor Modes, Up: Customization Variables ========= A "variable" is a Lisp symbol which has a value. Variable names can contain any characters, but by convention they are words separated by hyphens. A variable can also have a documentation string, which describes what kind of value it should have and how the value will be used. Lisp allows any variable to have any kind of value, but most variables that Emacs uses require a value of a certain type. Often the value has to be a string or a number. Sometimes we say that a certain feature is turned on if a variable is "non-`nil'," meaning that if the variable's value is `nil', the feature is off, but the feature is on for any other value. The conventional value to turn on the feature--since you have to pick one particular value when you set the variable--is `t'. Emacs uses many Lisp variables for internal recordkeeping, as any Lisp program must, but the most interesting variables for you are the ones that exist for the sake of customization. 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. These variables are called "options". Most options are documented in this manual and appear in the Variable Index (*note Variable Index::). One example of a variable which is an option is `fill-column', which specifies the position of the right margin (as a number of characters from the left margin) to be used by the fill commands (*note Filling::). * Menu: * Examining:: Examining or setting one variable's value. * Easy Customization:: Convenient and easy customization of variables. * Edit Options:: Examining or editing list of all variables' values. * Locals:: Per-buffer values of variables. * File Variables:: How files can specify variable values.  File: xemacs.info, Node: Examining, Next: Easy Customization, Up: Variables Examining and Setting Variables ------------------------------- `C-h v' `M-x describe-variable' Print the value and documentation of a variable. `M-x set-variable' Change the value of a variable. To examine the value of a single variable, use `C-h v' (`describe-variable'), which reads a variable name using the minibuffer, with completion. It prints both the value and the documentation of the variable. C-h v fill-column prints something like: fill-column's value is 75 Documentation: *Column beyond which automatic line-wrapping should happen. Automatically becomes local when set in any fashion. The star at the beginning of the documentation indicates that this variable is an option. `C-h v' is not restricted to options; it allows any variable name. If you know which option you want to set, you can use `M-x set-variable' to set it. This prompts for the variable name in the minibuffer (with completion), and then prompts for a Lisp expression for the new value using the minibuffer a second time. For example, M-x set-variable fill-column 75 sets `fill-column' to 75, as if you had executed the Lisp expression `(setq fill-column 75)'. Setting variables in this way, like all means of customizing Emacs except where explicitly stated, affects only the current Emacs session.  File: xemacs.info, Node: Easy Customization, Next: Edit Options, Prev: Examining, Up: Variables Easy Customization Interface ---------------------------- A convenient way to find the user option variables that you want to change, and then change them, is with `M-x customize'. This command creates a "customization buffer" with which you can browse through the Emacs user options in a logically organized structure, then edit and set their values. You can also use the customization buffer to save settings permanently. (Not all Emacs user options are included in this structure as of yet, but we are adding the rest.) * Menu: * Groups: Customization Groups. How options are classified in a structure. * Changing an Option:: How to edit a value and set an option. * Face Customization:: How to edit the attributes of a face. * Specific Customization:: Making a customization buffer for specific options, faces, or groups.  File: xemacs.info, Node: Customization Groups, Next: Changing an Option, Up: Easy Customization Customization Groups .................... For customization purposes, user options are organized into "groups" to help you find them. Groups are collected into bigger groups, all the way up to a master group called `Emacs'. `M-x customize' creates a customization buffer that shows the top-level `Emacs' group and the second-level groups immediately under it. It looks like this, in part: /- Emacs group: ---------------------------------------------------\ [State]: visible group members are all at standard settings. Customization of the One True Editor. See also [Manual]. [Open] Editing group Basic text editing facilities. [Open] External group Interfacing to external utilities. MORE SECOND-LEVEL GROUPS \- Emacs group end ------------------------------------------------/ This says that the buffer displays the contents of the `Emacs' group. The other groups are listed because they are its contents. But they are listed differently, without indentation and dashes, because _their_ contents are not included. Each group has a single-line documentation string; the `Emacs' group also has a `[State]' line. Most of the text in the customization buffer is read-only, but it typically includes some "editable fields" that you can edit. There are also "active fields"; this means a field that does something when you "invoke" it. To invoke an active field, either click on it with `Mouse-1', or move point to it and type . For example, the phrase `[Open]' that appears in a second-level group is an active field. Invoking the `[Open]' field for a group opens up a new customization buffer, which shows that group and its contents. This field is a kind of hypertext link to another group. The `Emacs' group does not include any user options itself, but other groups do. By examining various groups, you will eventually find the options and faces that belong to the feature you are interested in customizing. Then you can use the customization buffer to set them. You can view the structure of customization groups on a larger scale with `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. In this buffer, you can show the contents of a group by invoking `[+]'. When the group contents are visible, this button changes to `[-]'; invoking that hides the group contents. Each group, option or face name in this buffer has an active field which says `[Group]', `[Option]' or `[Face]'. Invoking that active field creates an ordinary customization buffer showing just that group and its contents, just that option, or just that face. This is the way to set values in it.  File: xemacs.info, Node: Changing an Option, Next: Face Customization, Prev: Customization Groups, Up: Easy Customization Changing an Option .................. Here is an example of what a user option looks like in the customization buffer: Kill Ring Max: [Hide] 30 [State]: this option is unchanged from its standard setting. Maximum length of kill ring before oldest elements are thrown away. The text following `[Hide]', `30' in this case, indicates the current value of the option. If you see `[Show]' instead of `[Hide]', it means that the value is hidden; the customization buffer initially hides values that take up several lines. Invoke `[Show]' to show the value. The line after the option name indicates the "customization state" of the option: in the example above, it says you have not changed the option yet. The word `[State]' at the beginning of this line is active; you can get a menu of various operations by invoking it with `Mouse-1' or . These operations are essential for customizing the variable. The line after the `[State]' line displays the beginning of the option's documentation string. If there are more lines of documentation, this line ends with `[More]'; invoke this to show the full documentation string. To enter a new value for `Kill Ring Max', move point to the value and edit it textually. For example, you can type `M-d', then insert another number. When you begin to alter the text, you will see the `[State]' line change to say that you have edited the value: [State]: you have edited the value as text, but not set the option. Editing the value does not actually set the option variable. To do that, you must "set" the option. To do this, invoke the word `[State]' and choose `Set for Current Session'. The state of the option changes visibly when you set it: [State]: you have set this option, but not saved it for future sessions. 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 unacceptable value. While editing a value or field that is a file name, directory name, command name, or anything else for which completion is defined, you can type `M-' (`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 active field `[Value Menu]' appears before the value; invoke this field to edit the value. For a boolean "on or off" value, the active field says `[Toggle]', and it changes to the other value. `[Value Menu]' and `[Toggle]' edit the buffer; the changes take effect when you use the `Set for Current Session' operation. Some options have values with complex structure. For example, the value of `load-path' is a list of directories. Here is how it appears in the customization buffer: Load Path: [INS] [DEL] [Current dir?]: /usr/local/share/emacs/19.34.94/site-lisp [INS] [DEL] [Current dir?]: /usr/local/share/emacs/site-lisp [INS] [DEL] [Current dir?]: /usr/local/share/emacs/19.34.94/leim [INS] [DEL] [Current dir?]: /usr/local/share/emacs/19.34.94/lisp [INS] [DEL] [Current dir?]: /build/emacs/e19/lisp [INS] [DEL] [Current dir?]: /build/emacs/e19/lisp/gnus [INS] [State]: this item has been changed outside the customization buffer. List of directories to search for files to load.... Each directory in the list appears on a separate line, and each line has several editable or active fields. You can edit any of the directory names. To delete a directory from the list, invoke `[DEL]' on that line. To insert a new directory in the list, invoke `[INS]' at the point where you want to insert it. You can also invoke `[Current dir?]' to switch between including a specific named directory in the path, and including `nil' in the path. (`nil' in a search path means "try the current directory.") Two special commands, and `S-', are useful for moving through the customization buffer. (`widget-forward') moves forward to the next active or editable field; `S-' (`widget-backward') moves backward to the previous active or editable field. Typing on an editable field also moves forward, just like . The reason for this is that people have a tendency to type when they are finished editing a field. If you have occasion to insert a newline in an editable field, use `C-o' or `C-q C-j', Setting the option changes its value in the current Emacs session; "saving" the value changes it for future sessions as well. This works by writing code into your init file so as to set the option variable again each time you start Emacs. *Note Init File::. To save the option, invoke `[State]' and select the `Save for Future Sessions' operation. You can also restore the option to its standard value by invoking `[State]' and selecting the `Reset' operation. There are actually three reset operations: `Reset to Current' If you have made some modifications and not yet set the option, this restores the text in the customization buffer to match the actual value. `Reset to Saved' This restores the value of the option to the last saved value, and updates the text accordingly. `Reset to Standard Settings' This sets the option 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. The state of a group indicates whether anything in that group has been edited, set or saved. You can select `Set for Current Session', `Save for Future Sessions' and the various kinds of `Reset' operation for the group; these operations on the group apply to all options in the group and its subgroups. Near the top of the customization buffer there are two lines containing several active fields: [Set] [Save] [Reset] [Done] Invoking `[Done]' buries this customization 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.  File: xemacs.info, Node: Face Customization, Next: Specific Customization, Prev: Changing an Option, Up: Easy Customization Customizing 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 the faces in the group appear in the customization buffer. Here is an example of how a face looks: Custom Changed Face: (sample) [State]: this face is unchanged from its standard setting. Face used when the customize item has been changed. Parent groups: [Custom Magic Faces] Attributes: [ ] Bold: [Toggle] off (nil) [ ] Italic: [Toggle] off (nil) [ ] Underline: [Toggle] off (nil) [ ] Foreground: white (sample) [ ] Background: blue (sample) [ ] Inverse: [Toggle] off (nil) [ ] Stipple: [ ] Font Family: [ ] Size: [ ] Strikethru: off Each face attribute has its own line. The `[X]' field before the attribute name indicates whether the attribute is "enabled"; `X' means that it is. You can enable or disable the attribute by invoking that field. When the attribute is enabled, you can change the attribute value in the usual ways. Setting, saving and resetting a face work like the same operations for options (*note Changing an Option::). A face can specify different appearances for different types of display. For example, a face can make text red on a color display, but use a bold font on a monochrome display. To specify multiple appearances for a face, select `Show Display Types' in the menu you get from invoking `[State]'.  File: xemacs.info, Node: Specific Customization, Prev: Face Customization, Up: Easy Customization 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. `M-x customize-option OPTION ' Set up a customization buffer with just one option, OPTION. `M-x customize-face FACE ' Set up a customization buffer with just one face, FACE. `M-x customize-group GROUP ' Set up a customization buffer with just one group, GROUP. `M-x customize-apropos REGEXP ' Set up a customization buffer with all the options, faces and groups that match REGEXP. `M-x customize-saved' Set up a customization buffer containing all options and faces that you have saved with customization buffers. `M-x customize-customized' Set up a customization buffer containing all options and faces that you have customized but not saved. If you want to alter a particular user option variable with the customization buffer, and you know its name, you can use the command `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. Likewise, you can modify a specific face, chosen by name, using `M-x customize-face'. You can also set up the customization buffer with a specific group, using `M-x customize-group'. The immediate contents of the chosen group, including option variables, faces, and other groups, all appear as well. However, these subgroups' own contents start out hidden. You can show their contents in the usual way, by invoking `[Show]'. To control more precisely what to customize, you can use `M-x customize-apropos'. You specify a regular expression as argument; then all options, faces and groups whose names match this regular expression are set up in the customization buffer. If you specify an empty regular expression, this includes _all_ groups, options and faces in the customization buffer (but that takes a long time). 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 `customize-saved' to look at the options and faces that you have saved. Use `M-x customize-customized' to look at the options and faces that you have set but not saved.  File: xemacs.info, Node: Edit Options, Next: Locals, Prev: Easy Customization, Up: Variables Editing Variable Values ----------------------- `M-x list-options' Display a buffer listing names, values, and documentation of all options. `M-x edit-options' Change option values by editing a list of options. `M-x list-options' displays a list of all Emacs option variables in an Emacs buffer named `*List Options*'. Each option is shown with its documentation and its current value. Here is what a portion of it might look like: ;; exec-path: ("." "/usr/local/bin" "/usr/ucb" "/bin" "/usr/bin" "/u2/emacs/etc") *List of directories to search programs to run in subprocesses. Each element is a string (directory name) or nil (try the default directory). ;; ;; fill-column: 75 *Column beyond which automatic line-wrapping should happen. Automatically becomes local when set in any fashion. ;; `M-x edit-options' goes one step further and immediately selects the `*List Options*' buffer; this buffer uses the major mode Options mode, which provides commands that allow you to point at an option and change its value: `s' Set the variable point is in or near to a new value read using the minibuffer. `x' Toggle the variable point is in or near: if the value was `nil', it becomes `t'; otherwise it becomes `nil'. `1' Set the variable point is in or near to `t'. `0' Set the variable point is in or near to `nil'. `n' `p' Move to the next or previous variable.  File: xemacs.info, Node: Locals, Next: File Variables, Prev: Edit Options, Up: Variables Local Variables --------------- `M-x make-local-variable' Make a variable have a local value in the current buffer. `M-x kill-local-variable' Make a variable use its global value in the current buffer. `M-x make-variable-buffer-local' Mark a variable so that setting it will make it local to the buffer that is current at that time. You can make any variable "local" to a specific Emacs buffer. This means that the variable's value in that buffer is independent of its value in other buffers. A few variables are always local in every buffer. All other Emacs variables have a "global" value which is in effect in all buffers that have not made the variable local. Major modes always make the variables they set local to the buffer. This is why changing major modes in one buffer has no effect on other buffers. `M-x make-local-variable' reads the name of a variable and makes it local to the current buffer. Further changes in this buffer will not affect others, and changes in the global value will not affect this buffer. `M-x make-variable-buffer-local' reads the name of a variable and changes the future behavior of the variable so that it automatically becomes local when it is set. More precisely, once you have marked a variable in this way, the usual ways of setting the variable will automatically invoke `make-local-variable' first. We call such variables "per-buffer" variables. Some important variables have been marked per-buffer already. They include `abbrev-mode', `auto-fill-function', `case-fold-search', `comment-column', `ctl-arrow', `fill-column', `fill-prefix', `indent-tabs-mode', `left-margin', `mode-line-format', `overwrite-mode', `selective-display-ellipses', `selective-display', `tab-width', and `truncate-lines'. Some other variables are always local in every buffer, but they are used for internal purposes. Note: the variable `auto-fill-function' was formerly named `auto-fill-hook'. If you want a variable to cease to be local to the current buffer, call `M-x kill-local-variable' and provide the name of a variable to the prompt. The global value of the variable is again in effect in this buffer. Setting the major mode kills all the local variables of the buffer. To set the global value of a variable, regardless of whether the variable has a local value in the current buffer, you can use the Lisp function `setq-default'. It works like `setq'. If there is a local value in the current buffer, the local value is not affected by `setq-default'; thus, the new global value may not be visible until you switch to another buffer, as in the case of: (setq-default fill-column 75) `setq-default' is the only way to set the global value of a variable that has been marked with `make-variable-buffer-local'. Programs can look at a variable's default value with `default-value'. This function takes a symbol as an argument and returns its default value. The argument is evaluated; usually you must quote it explicitly, as in the case of: (default-value 'fill-column)