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Info file emacs, produced by texinfo-format-buffer -*-Text-*- from file emacs.tex This file documents the GNU Emacs editor. Copyright (C) 1985, 1986 Richard M. Stallman. 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 Emacs 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 Emacs General Public License" may be included in a translation approved by the author instead of in the original English. File: emacs Node: Fortran Columns, Prev: Fortran Comments, Up: Fortran, Next: Fortran Abbrev Columns ------- `C-c C-r' Displays a "column ruler" momentarily above the current line (`fortran-column-ruler'). `C-c C-w' Splits the current window horizontally so that it is 72 columns wide. This may help you avoid going over that limit (`fortran-window-create'). The command `C-c C-r' (`fortran-column-ruler') shows a column ruler momentarily above the current line. The comment ruler is two lines of text that show you the locations of columns with special significance in Fortran programs. Square brackets show the limits of the columns for line numbers, and curly brackets show the limits of the columns for the statement body. Column numbers appear above them. Note that the column numbers count from zero, as always in GNU Emacs. As a result, the numbers may not be those you are familiar with; but the actual positions in the line are standard Fortran. The text used to display the column ruler is the value of the variable `fortran-comment-ruler'. By changing this variable, you can change the display. For even more help, use `C-c C-w' (`fortran-create-window'), a command which splits the current window horizontally, making a window 72 columns wide. By editing in this window you can immediately see when you make a line too wide to be correct Fortran. File: emacs Node: Fortran Abbrev, Prev: Fortran Columns, Up: Fortran Fortran Keyword Abbrevs ----------------------- Fortran mode provides many built-in abbrevs for common keywords and declarations. These are the same sort of abbrev that you can define yourself. To use them, you must turn on Abbrev mode. *Note Abbrevs::. The built-in abbrevs are unusual in one way: they all start with a semicolon. You cannot normally use semicolon in an abbrev, but Fortran mode makes this possible by changing the syntax of semicolon to "word constituent". For example, one built-in Fortran abbrev is `;c' for `continue'. If you insert `;c' and then insert a punctuation character such as a space or a newline, the `;c' will change automatically to `continue', provided Abbrev mode is enabled. Type `;?' or `;C-h' to display a list of all the built-in Fortran abbrevs and what they stand for. File: emacs Node: Running, Prev: Programs, Up: Top, Next: Abbrevs Compiling and Testing Programs ****************************** The previous chapter discusses the Emacs commands that are useful for making changes in programs. This chapter deals with commands that assist in the larger process of developing and maintaining programs. * Menu: * Compilation:: Compiling programs in languages other than Lisp (C, Pascal, etc.) * Modes: Lisp Modes. Various modes for editing Lisp programs, with different facilities for running the Lisp programs. * Libraries: Lisp Libraries. Creating Lisp programs to run in Emacs. * Interaction: Lisp Interaction. Executing Lisp in an Emacs buffer. * Eval: Lisp Eval. Executing a single Lisp expression in Emacs. * Debug: Lisp Debug. Debugging Lisp programs running in Emacs. * External Lisp:: Communicating through Emacs with a separate Lisp. File: emacs Node: Compilation, Prev: Running, Up: Running, Next: Lisp Modes Running `make', or Compilers Generally ====================================== Emacs can run compilers for noninteractive languages such as C and Fortran as inferior processes, feeding the error log into an Emacs buffer. It can also parse the error messages and visit the files in which errors are found, moving point right to the line where the error occurred. `M-x compile' Run a compiler asynchronously under Emacs, with error messages to `*compilation*' buffer. `M-x grep' Run `grep' asynchronously under Emacs, with matching lines listed in the buffer named `*compilation*'. `M-x kill-compiler' `M-x kill-grep' Kill the running compilation or `grep' subprocess. `C-x `' Visit the locus of the next compiler error message or `grep' match. To run `make' or another compiler, do `M-x compile'. This command reads a shell command line using the minibuffer, and then executes the specified command line in an inferior shell with output going to the buffer named `*compilation*'. The current buffer's default directory is used as the working directory for the execution of the command; normally, therefore, the makefile comes from this directory. When the shell command line is read, the minibuffer appears containing a default command line, which is the command you used the last time you did `M-x compile'. If you type just RET, the same command line is used again. The first `M-x compile' provides `make -k' as the default. The default is taken from the variable `compile-command'; if the appropriate compilation command for a file is something other than `make -k', it can be useful to have the file specify a local value for `compile-command' (*Note File Variables::). Starting a compilation causes the buffer `*compilation*' to be displayed in another window but not selected. Its mode line tells you whether compilation is finished, with the word `run' or `exit' inside the parentheses. You do not have to keep this buffer visible; compilation continues in any case. To kill the compilation process, do `M-x kill-compilation'. You will see that the mode line of the `*compilation*' buffer changes to say `signal' instead of `run'. Starting a new compilation also kills any running compilation, as only one can exist at any time. However, this requires confirmation before actually killing a compilation that is running. To parse the compiler error messages, type `C-x `' (`next-error'). The character following the `C-x' is the grave accent, not the single quote. This command displays the buffer `*compilation*' in one window and the buffer in which the next error occurred in another window. Point in that buffer is moved to the line where the error was found. The corresponding error message is scrolled to the top of the window in which `*compilation*' is displayed. The first time `C-x `' is used after the start of a compilation, it parses all the error messages, visits all the files that have error messages, and makes markers pointing at the lines that the error messages refer to. Then it moves to the first error message location. Subsequent uses of `C-x `' advance down the data set up by the first use. When the preparsed error messages are exhausted, the next `C-x `' checks for any more error messages that have come in; this is useful if you start editing the compiler errors while the compilation is still going on. If no more error messages have come in, `C-x `' reports an error. `C-u C-x `' discards the preparsed error message data and parses the `*compilation*' buffer over again, then displaying the first error. This way, you can process the same set of errors again. Instead of running a compiler, you can run `grep' and see the lines on which matches were found. To do this, type `M-x grep' with an argument line that contains the same arguments you would give `grep' when running it normally: a `grep'-style regexp (usually in singlequotes to quote the shell's special characters) followed by filenames which may use wildcards. The output from `grep' goes in the `*compilation*' buffer and the lines that matched can be found with `C-x `' as if they were compilation errors. Note: a shell is used to run the compile command, but the shell is told that it should be noninteractive. This means in particular that the shell starts up with no prompt. If you find your usual shell prompt making an unsightly appearance in the `*compilation*' buffer, it means you have made a mistake in your shell's init file (`.cshrc' or `.shrc' or ...) by setting the prompt unconditionally. The shell init file should set the prompt only if there already is a prompt. In `csh', here is how to do it: if ($?prompt) set prompt = ... File: emacs Node: Lisp Modes, Prev: Compilation, Up: Running, Next: Lisp Libraries Major Modes for Lisp ==================== Emacs has four different major modes for Lisp. They are the same in terms of editing commands, but differ in the commands for executing Lisp expressions. Emacs-Lisp mode The mode for editing source files of programs to run in Emacs Lisp. This mode defines `C-M-x' to evaluate the current defun. *Note Lisp Libraries::. Lisp Interaction mode The mode for an interactive session with Emacs Lisp. It defines LFD to evaluate the sexp before point and insert its value in the buffer. *Note Lisp Interaction::. Lisp mode The mode for editing source files of programs that run in Lisps other than Emacs Lisp. This mode defines `C-M-x' to send the current defun to an inferior Lisp process. *Note External Lisp::. Inferior Lisp mode The mode for an interactive session with an inferior Lisp process. This mode combines the special features of Lisp mode and Shell mode (*Note Shell Mode::). Scheme mode Like Lisp mode but for Scheme programs. Inferior Scheme mode The mode for an interactive session with an inferior Scheme process. File: emacs Node: Lisp Libraries, Prev: Lisp Modes, Up: Running, Next: Lisp Eval Libraries of Lisp Code for Emacs ================================ Lisp code for Emacs editing commands is stored in files whose names conventionally end in `.el'. This ending tells Emacs to edit them in Emacs-Lisp mode (*Note Lisp Modes::). * Menu: * Loading:: Loading libraries of Lisp code into Emacs for use. * Compiling Libraries:: Compiling a library makes it load and run faster. * Mocklisp:: Converting Mocklisp to Lisp so GNU Emacs can run it. File: emacs Node: Loading, Prev: Lisp Libraries, Up: Lisp Libraries, Next: Compiling Libraries Loading Libraries ----------------- To execute a file of Emacs Lisp, use `M-x load-file'. This command reads a file name using the minibuffer and then executes the contents of that file as Lisp code. It is not necessary to visit the file first; in any case, this command reads the file as found on disk, not text in an Emacs buffer. Once a file of Lisp code is installed in the Emacs Lisp library directories, users can load it using `M-x load-library'. Programs can load it by calling `load-library', or with `load', a more primitive function that is similar but accepts some additional arguments. `M-x load-library' differs from `M-x load-file' in that it searches a sequence of directories and tries three file names in each directory. The three names are, first, the specified name with `.elc' appended; second, with `.el' appended; third, the specified name alone. A `.elc' file would be the result of compiling the Lisp file into byte code; it is loaded if possible in preference to the Lisp file itself because the compiled file will load and run faster. Because the argument to `load-library' is usually not in itself a valid file name, file name completion is not available. Indeed, when using this command, you usually do not know exactly what file name will be used. The sequence of directories searched by `M-x load-library' is specified by the variable `load-path', a list of strings that are directory names. The default value of the list contains the directory where the Lisp code for Emacs itself is stored. If you have libraries of your own, put them in a single directory and add that directory to `load-path'. `nil' in this list stands for the current default directory, but it is probably not a good idea to put `nil' in the list. If you find yourself wishing that `nil' were in the list, most likely what you really want to do is use `M-x load-file' this once. Often you do not have to give any command to load a library, because the commands defined in the library are set up to "autoload" that library. Running any of those commands causes `load' to be called to load the library; this replaces the autoload definitions with the real ones from the library. If autoloading a file does not finish, either because of an error or because of a `C-g' quit, all function definitions made by the file are undone automatically. So are any calls to `provide'. As a consequence, if you use one of the autoloadable commands again, the entire file will be loaded a second time. This prevents problems where the command is no longer autoloading but it works wrong because not all the file was loaded. Function definitions are undone only for autoloading; explicit calls to `load' do not undo anything if loading is not completed. File: emacs Node: Compiling Libraries, Prev: Loading, Up: Lisp Libraries, Next: Mocklisp Compiling Libraries ------------------- Emacs Lisp code can be compiled into byte-code which loads faster, takes up less space when loaded, and executes faster. The way to make a byte-code compiled file from an Emacs-Lisp source file is with `M-x byte-compile-file'. The default argument for this function is the file visited in the current buffer. It reads the specified file, compiles it into byte code, and writes an output file whose name is made by appending `c' to the input file name. Thus, the file `rmail.el' would be compiled into `rmail.elc'. To recompile the changed Lisp files in a directory, use `M-x byte-recompile-directory'. Specify just the directory name as an argument. Each `.el' file that has been byte-compiled before is byte-compiled again if it has changed since the previous compilation. A numeric argument to this command tells it to offer to compile each `.el' file that has not already been compiled. You must answer `y' or `n' to each offer. Emacs can be invoked noninteractively from the shell to do byte compilation with the aid of the function `batch-byte-compile'. In this case, the files to be compiled are specified with command-line arguments. Use a shell command of the form emacs -batch -f batch-byte-compile FILES... Directory names may also be given as arguments; `byte-recompile-directory' is invoked (in effect) on each such directory. `batch-byte-compile' uses all the remaining command-line arguments as file or directory names, then kills the Emacs process. `M-x disassemble' explains the result of byte compilation. Its argument is a function name. It displays the byte-compiled code in a help window in symbolic form, one instruction per line. If the instruction refers to a variable or constant, that is shown too. File: emacs Node: Mocklisp, Prev: Compiling Libraries, Up: Lisp Libraries Converting Mocklisp to Lisp --------------------------- GNU Emacs can run Mocklisp files by converting them to Emacs Lisp first. To convert a Mocklisp file, visit it and then type `M-x convert-mocklisp-buffer'. Then save the resulting buffer of Lisp file in a file whose name ends in `.el' and use the new file as a Lisp library. It does not currently work to byte-compile converted Mocklisp code. This is because converted Mocklisp code uses some special Lisp features to deal with Mocklisp's incompatible ideas of how arguments are evaluated and which values signify "true" or "false". File: emacs Node: Lisp Eval, Prev: Lisp Libraries, Up: Running, Next: Lisp Debug Evaluating Emacs-Lisp Expressions ================================= Lisp programs intended to be run in Emacs should be edited in Emacs-Lisp mode; this will happen automatically for file names ending in `.el'. By contrast, Lisp mode itself is used for editing Lisp programs intended for other Lisp systems. Emacs-Lisp mode can be selected with the command `M-x emacs-lisp-mode'. For testing of Lisp programs to run in Emacs, it is useful to be able to evaluate part of the program as it is found in the Emacs buffer. For example, after changing the text of a Lisp function definition, evaluating the definition installs the change for future calls to the function. Evaluation of Lisp expressions is also useful in any kind of editing task for invoking noninteractive functions (functions that are not commands). `M-ESC' Read a Lisp expression in the minibuffer, evaluate it, and print the value in the minibuffer (`eval-expression'). `C-x C-e' Evaluate the Lisp expression before point, and print the value in the minibuffer (`eval-last-sexp'). `C-M-x' Evaluate the defun containing or after point, and print the value in the minibuffer (`eval-defun'). `M-x eval-region' Evaluate all the Lisp expressions in the region. `M-x eval-current-buffer' Evaluate all the Lisp expressions in the buffer. `M-ESC' (`eval-expression') is the most basic command for evaluating a Lisp expression interactively. It reads the expression using the minibuffer, so you can execute any expression on a buffer regardless of what the buffer contains. When the expression is evaluated, the current buffer is once again the buffer that was current when `M-ESC' was typed. `M-ESC' can easily confuse users who do not understand it, especially on keyboards with autorepeat where it can result from holding down the ESC key for too long. Therefore, `eval-expression' 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 for it. *Note Disabling::. In Emacs-Lisp mode, the key `C-M-x' is bound to the function `eval-defun', which parses the defun containing or following point as a Lisp expression and evaluates it. The value is printed in the echo area. This command is convenient for installing in the Lisp environment changes that you have just made in the text of a function definition. The command `C-x C-e' (`eval-last-sexp') performs a similar job but is available in all major modes, not just Emacs-Lisp mode. It finds the sexp before point, reads it as a Lisp expression, evaluates it, and prints the value in the echo area. It is sometimes useful to type in an expression and then, with point still after it, type `C-x C-e'. If `C-M-x' or `C-x C-e' is given a numeric argument, it prints the value by insertion into the current buffer at point, rather than in the echo area. The argument value does not matter. The most general command for evaluating Lisp expressions from a buffer is `eval-region'. `M-x eval-region' parses the text of the region as one or more Lisp expressions, evaluating them one by one. `M-x eval-current-buffer' is similar but evaluates the entire buffer. This is a reasonable way to install the contents of a file of Lisp code that you are just ready to test. After finding and fixing a bug, use `C-M-x' on each function that you change, to keep the Lisp world in step with the source file. File: emacs Node: Lisp Debug, Prev: Lisp Eval, Up: Running, Next: Lisp Interaction The Emacs-Lisp Debugger ======================= GNU Emacs contains a debugger for Lisp programs executing inside it. This debugger is normally not used; many commands frequently get Lisp errors when invoked in inappropriate contexts (such as `C-f' at the end of the buffer) and it would be very unpleasant for that to enter a special debugging mode. When you want to make Lisp errors invoke the debugger, you must set the variable `debug-on-error' to non-`nil'. Quitting with `C-g' is not considered an error, and `debug-on-error' has no effect on the handling of `C-g'. However, if you set `debug-on-quit' non-`nil', `C-g' will invoke the debugger. This can be useful for debugging an infinite loop; type `C-g' once the loop has had time to reach its steady state. `debug-on-quit' has no effect on errors. You can also cause the debugger to be entered when a specified function is called, or at a particular place in Lisp code. Use `M-x debug-on-entry' with argument FUN-NAME to cause function FUN-NAME to enter the debugger as soon as it is called. Use `M-x cancel-debug-on-entry' to make the function stop entering the debugger when called. (Redefining the function also does this.) To enter the debugger from some other place in Lisp code, you must insert the expression `(debug)' there and install the changed code with `C-M-x'. *Note Lisp Eval::. When the debugger is entered, it displays the previously selected buffer in one window and a buffer named `*Backtrace*' in another window. The backtrace buffer contains one line for each level of Lisp function execution currently going on. At the beginning of this buffer is a message describing the reason that the debugger was invoked (such as, what error message if it was invoked due to an error). The backtrace buffer is read-only, and is in a special major mode, Backtrace mode, in which letters are defined as debugger commands. The usual Emacs editing commands are available; you can switch windows to examine the buffer that was being edited at the time of the error, and you can also switch buffers, visit files, and do any other sort of editing. However, the debugger is a recursive editing level (*Note Recursive Edit::) and it is wise to go back to the backtrace buffer and exit the debugger officially when you don't want to use it any more. Exiting the debugger kills the backtrace buffer. The contents of the backtrace buffer show you the functions that are executing and the arguments that were given to them. It has the additional purpose of allowing you to specify a stack frame by moving point to the line describing that frame. The frame whose line point is on is considered the "current frame". Some of the debugger commands operate on the current frame. Debugger commands are mainly used for stepping through code an expression at a time. Here is a list of them. `c' Exit the debugger and continue execution. In most cases, execution of the program continues as if the debugger had never been entered (aside from the effect of any variables or data structures you may have changed while inside the debugger). This includes entry to the debugger due to function entry or exit, explicit invocation, quitting or certain errors. Most errors cannot be continued; trying to continue one of them causes the same error to occur again. `d' Continue execution, but enter the debugger the next time a Lisp function is called. This allows you to step through the subexpressions of an expression, seeing what values the subexpressions compute and what else they do. The stack frame made for the function call which enters the debugger in this way will be flagged automatically for the debugger to be called when the frame is exited. You can use the `u' command to cancel this flag. `b' Set up to enter the debugger when the current frame is exited. Frames that will invoke the debugger on exit are flagged with stars. `u' Don't enter the debugger when the current frame is exited. This cancels a `b' command on that frame. `e' Read a Lisp expression in the minibuffer, evaluate it, and print the value in the echo area. This is the same as the command `M-ESC', except that `e' is not normally disabled like `M-ESC'. `q' Terminate the program being debugged; return to top-level Emacs command execution. If the debugger was entered due to a `C-g' but you really want to quit, not to debug, use the `q' command. `r' Return a value from the debugger. The value is computed by reading an expression with the minibuffer and evaluating it. The value returned by the debugger makes a difference when the debugger was invoked due to exit from a Lisp call frame (as requested with `b'); then the value specified in the `r' command is used as the value of that frame. The debugger's return value also matters with many errors. For example, `wrong-type-argument' errors will use the debugger's return value instead of the invalid argument; `no-catch' errors will use the debugger value as a throw tag instead of the tag that was not found. If an error was signaled by calling the Lisp function `signal', the debugger's return value is returned as the value of `signal'. File: emacs Node: Lisp Interaction, Prev: Lisp Debug, Up: Running, Next: External Lisp Lisp Interaction Buffers ======================== The buffer `*scratch*' which is selected when Emacs starts up is provided for evaluating Lisp expressions interactively inside Emacs. Both the expressions you evaluate and their output goes in the buffer. The `*scratch*' buffer's major mode is Lisp Interaction mode, which is the same as Emacs-Lisp mode except for one command, LFD. In Emacs-Lisp mode, LFD is an indentation command, as usual. In Lisp Interaction mode, LFD is bound to `eval-print-last-sexp'. This function reads the Lisp expression before point, evaluates it, and inserts the value in printed representation before point. Thus, the way to use the `*scratch*' buffer is to insert Lisp expressions at the end, ending each one with LFD so that it will be evaluated. The result is a complete typescript of the expressions you have evaluated and their values. The rationale for this feature is that Emacs must have a buffer when it starts up, but that buffer is not useful for editing files since a new buffer is made for every file that you visit. The Lisp interpreter typescript is the most useful thing I can think of for the initial buffer to do. `M-x lisp-interaction-mode' will put any buffer in Lisp Interaction mode. File: emacs Node: External Lisp, Prev: Lisp Interaction, Up: Running Running an External Lisp ======================== Emacs has facilities for running programs in other Lisp systems. You can run a Lisp process as an inferior of Emacs, and pass expressions to it to be evaluated. You can also pass changed function definitions directly from the Emacs buffers in which you edit the Lisp programs to the inferior Lisp process. To run an inferior Lisp process, type `M-x run-lisp'. This runs the program named `lisp', the same program you would run by typing `lisp' as a shell command, with both input and output going through an Emacs buffer named `*lisp*'. That is to say, any "terminal output" from Lisp will go into the buffer, advancing point, and any "terminal input" for Lisp comes from text in the buffer. To give input to Lisp, go to the end of the buffer and type the input, terminated by RET. The `*lisp*' buffer is in Inferior Lisp mode, a mode which has all the special characteristics of Lisp mode and Shell mode (*Note Shell Mode::). For the source files of programs to run in external Lisps, use Lisp mode. This mode can be selected with `M-x lisp-mode', and is used automatically for files whose names end in `.l' or `.lisp', as most Lisp systems usually expect. When you edit a function in a Lisp program you are running, the easiest way to send the changed definition to the inferior Lisp process is the key `C-M-x'. In Lisp mode, this runs the function `lisp-send-defun', which finds the defun around or following point and sends it as input to the Lisp process. (Emacs can send input to any inferior process regardless of what buffer is current.) Contrast the meanings of `C-M-x' in Lisp mode (for editing programs to be run in another Lisp system) and Emacs-Lisp mode (for editing Lisp programs to be run in Emacs): in both modes it has the effect of installing the function definition that point is in, but the way of doing so is different according to where the relevant Lisp environment is found. *Note Lisp Modes::. File: emacs Node: Abbrevs, Prev: Running, Up: Top, Next: Picture Abbrevs ******* An "abbrev" is a word which "expands", if you insert it, into some different text. Abbrevs are defined by the user to expand in specific ways. For example, you might define `foo' as an abbrev expanding to `find outer otter'. With this abbrev defined, you would be able to get `find outer otter ' into the buffer by typing `f o o SPC'. Abbrevs expand only when Abbrev mode (a minor mode) is enabled. Disabling Abbrev mode does not cause abbrev definitions to be forgotten, but they do not expand until Abbrev mode is enabled again. The command `M-x abbrev-mode' toggles Abbrev mode; with a numeric argument, it turns Abbrev mode on if the argument is positive, off otherwise. *Note Minor Modes::. `abbrev-mode' is also a variable; Abbrev mode is on when the variable is non-`nil'. The variable `abbrev-mode' automatically becomes local to the current buffer when it is set. Abbrev definitions can be "mode-specific"---active only in one major mode. Abbrevs can also have "global" definitions that are active in all major modes. The same abbrev can have a global definition and various mode-specific definitions for different major modes. A mode specific definition for the current major mode overrides a global definition. Abbrevs can be defined interactively during the editing session. Lists of abbrev definitions can also be saved in files and reloaded in later sessions. Some users keep extensive lists of abbrevs that they load in every session. A second kind of abbreviation facility is called the "dynamic expansion". Dynamic abbrev expansion happens only when you give an explicit command and the result of the expansion depends only on the current contents of the buffer. *Note Dynamic Abbrevs::. * Menu: * Defining Abbrevs:: Defining an abbrev, so it will expand when typed. * Expanding Abbrevs:: Controlling expansion: prefixes, canceling expansion. * Editing Abbrevs:: Viewing or editing the entire list of defined abbrevs. * Saving Abbrevs:: Saving the entire list of abbrevs for another session. * Dynamic Abbrevs:: Abbreviations for words already in the buffer. File: emacs Node: Defining Abbrevs, Prev: Abbrevs, Up: Abbrevs, Next: Expanding Abbrevs Defining Abbrevs ================ `C-x +' Define an abbrev to expand into some text before point (`add-global-abbrev'). `C-x C-a' Similar, but define an abbrev available only in the current major mode (`add-mode-abbrev'). `C-x -' Define a word in the buffer as an abbrev (`inverse-add-global-abbrev'). `C-x C-h' Define a word in the buffer as a mode-specific abbrev (`inverse-add-mode-abbrev'). `M-x kill-all-abbrevs' After this command, there are no abbrev definitions in effect. The usual way to define an abbrev is to enter the text you want the abbrev to expand to, position point after it, and type `C-x +' (`add-global-abbrev'). This reads the abbrev itself using the minibuffer, and then defines it as an abbrev for one or more words before point. Use a numeric argument to say how many words before point should be taken as the expansion. For example, to define the abbrev `foo' as mentioned above, insert the text `find outer otter' and then type `C-u 3 C-x + f o o RET'. An argument of zero to `C-x +' means to use the contents of the region as the expansion of the abbrev being defined. The command `C-x C-a' (`add-mode-abbrev') is similar, but defines a mode-specific abbrev. Mode specific abbrevs are active only in a particular major mode. `C-x C-a' defines an abbrev for the major mode in effect at the time `C-x C-a' is typed. The arguments work the same as for `C-x +'. If the text of the abbrev you want is already in the buffer instead of the expansion, use command `C-x -' (`inverse-add-global-abbrev') instead of `C-x +', or use `C-x C-h' (`inverse-add-mode-abbrev') instead of `C-x C-a'. These commands are called "inverse" because they invert the meaning of the argument found in the buffer and the argument read using the minibuffer. To change the definition of an abbrev, just add the new definition. You will be asked to confirm if the abbrev has a prior definition. To remove an abbrev definition, give a negative argument to `C-x +' or `C-x C-a'. You must choose the command to specify whether to kill a global definition or a mode-specific definition for the current mode, since those two definitions are independent for one abbrev. `M-x kill-all-abbrevs' removes all the abbrev definitions there are. File: emacs Node: Expanding Abbrevs, Prev: Defining Abbrevs, Up: Abbrevs, Next: Editing Abbrevs Controlling Abbrev Expansion ============================ An abbrev expands whenever it is present in the buffer just before point and a self-inserting punctuation character (SPC, comma, etc.) is typed. Most often the way an abbrev is used is to insert the abbrev followed by punctuation. Abbrev expansion preserves case; thus, `foo' expands into `find outer otter'; `Foo' into `Find outer otter', and `FOO' into `FIND OUTER OTTER' or `Find Outer Otter' according to the variable `abbrev-all-caps' (a non-`nil' value chooses the first of the two expansions). These two commands are used to control abbrev expansion: `M-'' Separate a prefix from a following abbrev to be expanded (`abbrev-prefix-mark'). `C-x '' Expand the abbrev before point (`expand-abbrev'). This is effective even when Abbrev mode is not enabled. `M-x unexpand-abbrev' Undo last abbrev expansion. `M-x expand-region-abbrevs' Expand some or all abbrevs found in the region. You may wish to expand an abbrev with a prefix attached; for example, if `cnst' expands into `construction', you might want to use it to enter `reconstruction'. It does not work to type `recnst', because that is not necessarily a defined abbrev. What does work is to use the command `M-'' (`abbrev-prefix-mark') in between the prefix `re' and the abbrev `cnst'. First, insert `re'. Then type `M-''; this inserts a minus sign in the buffer to indicate that it has done its work. Then insert the abbrev `cnst'; the buffer now contains `re-cnst'. Now insert a punctuation character to expand the abbrev `cnst' into `construction'. The minus sign is deleted at this point, because `M-'' left word for this to be done. The resulting text is the desired `reconstruction'. If you actually want the text of the abbrev in the buffer, rather than its expansion, you can accomplish this by inserting the following punctuation with `C-q'. Thus, `foo C-q -' leaves `foo-' in the buffer. If you expand an abbrev by mistake, you can undo the expansion (replace the expansion by the original abbrev text) with `M-x unexpand-abbrev'. `C-_' (`undo') can also be used to undo the expansion; but first it will undo the insertion of the following punctuation character! `M-x expand-region-abbrevs' searches through the region for defined abbrevs, and for each one found offers to replace it with its expansion. This command is useful if you have typed in text using abbrevs but forgot to turn on Abbrev mode first. It may also be useful together with a special set of abbrev definitions for making several global replacements at once. This command is effective even if Abbrev mode is not enabled. File: emacs Node: Editing Abbrevs, Prev: Expanding Abbrevs, Up: Abbrevs, Next: Saving Abbrevs Examining and Editing Abbrevs ============================= `M-x list-abbrevs' Print a list of all abbrev definitions. `M-x edit-abbrevs' Edit a list of abbrevs; you can add, alter or remove definitions. The output from `M-x list-abbrevs' looks like this: (lisp-mode-abbrev-table) "dk" 0 "define-key" (global-abbrev-table) "dfn" 0 "definition" (Some blank lines of no semantic significance, and some other abbrev tables, have been omitted.) A line containing a name in parentheses is the header for abbrevs in a particular abbrev table; `global-abbrev-table' contains all the global abbrevs, and the other abbrev tables that are named after major modes contain the mode-specific abbrevs. Within each abbrev table, each nonblank line defines one abbrev. The word at the beginning is the abbrev. The number that appears is the number of times the abbrev has been expanded. Emacs keeps track of this to help you see which abbrevs you actually use, in case you decide to eliminate those that you don't use often. The string at the end of the line is the expansion. `M-x edit-abbrevs' allows you to add, change or kill abbrev definitions by editing a list of them in an Emacs buffer. The list has the same format described above. The buffer of abbrevs is called `*Abbrevs*', and is in Edit-Abbrevs mode. This mode redefines the key `C-c C-c' to install the abbrev definitions as specified in the buffer. The command that does this is `edit-abbrevs-redefine'. Any abbrevs not described in the buffer are eliminated when this is done. `edit-abbrevs' is actually the same as `list-abbrevs' except that it selects the buffer `*Abbrevs*' whereas `list-abbrevs' merely displays it in another window. File: emacs Node: Saving Abbrevs, Prev: Editing Abbrevs, Up: Abbrevs, Next: Dynamic Abbrevs Saving Abbrevs ============== These commands allow you to keep abbrev definitions between editing sessions. `M-x write-abbrev-file' Write a file describing all defined abbrevs. `M-x read-abbrev-file' Read such a file and define abbrevs as specified there. `M-x quietly-read-abbrev-file' Similar but do not display a message about what is going on. `M-x define-abbrevs' Define abbrevs from buffer. `M-x insert-abbrevs' Insert all abbrevs and their expansions into the buffer. `M-x write-abbrev-file' reads a file name using the minibuffer and writes a description of all current abbrev definitions into that file. The text stored in the file looks like the output of `M-x list-abbrevs'. This is used to save abbrev definitions for use in a later session. `M-x read-abbrev-file' reads a file name using the minibuffer and reads the file, defining abbrevs according to the contents of the file. `M-x quietly-read-abbrev-file' is the same except that it does not display a message in the echo area saying that it is doing its work; it is actually useful primarily in the `.emacs' file. If an empty argument is given to either of these functions, the file name used is the value of the variable `abbrev-file-name', which is by default `"~/.abbrev_defs"'. Emacs will offer to save abbrevs automatically if you have changed any of them, whenever it offers to save all files (for `C-x s' or `C-x C-c'). This feature can be inhibited by setting the variable `save-abbrevs' to `nil'. The commands `M-x insert-abbrevs' and `M-x define-abbrevs' are similar to the previous commands but work on text in an Emacs buffer. `M-x insert-abbrevs' inserts text into the current buffer before point, describing all current abbrev definitions; `M-x define-abbrevs' parses the entire current buffer and defines abbrevs accordingly. File: emacs Node: Dynamic Abbrevs, Prev: Saving Abbrevs, Up: Abbrevs Dynamic Abbrev Expansion ======================== The abbrev facility described above operates automatically as you insert text, but all abbrevs must be defined explicitly. By contrast, "dynamic abbrevs" allow the meanings of abbrevs to be determined automatically from the contents of the buffer, but dynamic abbrev expansion happens only when you request it explicitly. `M-/' Expand the word in the buffer before point as a "dynamic abbrev", by searching in the buffer for words starting with that abbreviation (`dabbrev-expand'). For example, if the buffer contains `does this follow ' and you type `f o M-/', the effect is to insert `follow' because that is the last word in the buffer that starts with `fo'. A numeric argument to `M-/' says to take the second, third, etc. distinct expansion found looking backward from point. Repeating `M-/' searches for an alternative expansion by looking farther back. After the entire buffer before point has been considered, the buffer after point is searched. Dynamic abbrev expansion is completely independent of Abbrev mode; the expansion of a word with `M-/' is completely independent of whether it has a definition as an ordinary abbrev. File: emacs Node: Picture, Prev: Abbrevs, Up: Top, Next: Sending Mail Editing Pictures **************** If you want to create a picture made out of text characters (for example, a picture of the division of a register into fields, as a comment in a program), use the command `edit-picture' to enter Picture mode. In Picture mode, editing is based on the "quarter-plane" model of text, according to which the text characters lie studded on an area that stretches infinitely far to the right and downward. The concept of the end of a line does not exist in this model; the most you can say is where the last nonblank character on the line is found. Of course, Emacs really always considers text as a sequence of characters, and lines really do have ends. But in Picture mode most frequently-used keys are rebound to commands that simulate the quarter-plane model of text. They do this by inserting spaces or by converting tabs to spaces. Most of the basic editing commands of Emacs are redefined by Picture mode to do essentially the same thing but in a quarter-plane way. In addition, Picture mode defines various keys starting with the `C-c' prefix to run special picture editing commands. One of these keys, `C-c C-c', is pretty important. Often a picture is part of a larger file that is usually edited in some other major mode. `M-x edit-picture' records the name of the previous major mode, and then you can use the `C-c C-c' command (`picture-mode-exit') to restore that mode. `C-c C-c' also deletes spaces from the ends of lines, unless given a numeric argument. The commands used in Picture mode all work in other modes (provided the `picture' library is loaded), but are not bound to keys except in Picture mode. Note that the descriptions below talk of moving "one column" and so on, but all the picture mode commands handle numeric arguments as their normal equivalents do. Turning on Picture mode calls the value of the variable `picture-mode-hook' as a function, with no arguments, if that value exists and is non-`nil'. * Menu: * Basic Picture:: Basic concepts and simple commands of Picture Mode. * Insert in Picture:: Controlling direction of cursor motion after "self-inserting" characters. * Tabs in Picture:: Various features for tab stops and indentation. * Rectangles in Picture:: Clearing and superimposing rectangles. File: emacs Node: Basic Picture, Prev: Picture, Up: Picture, Next: Insert in Picture Basic Editing in Picture Mode ============================= Most keys do the same thing in Picture mode that they usually do, but do it in a quarter-plane style. For example, `C-f' is rebound to run `picture-forward-column', which is defined to move point one column to the right, by inserting a space if necessary, so that the actual end of the line makes no difference. `C-b' is rebound to run `picture-backward-column', which always moves point left one column, converting a tab to multiple spaces if necessary. `C-n' and `C-p' are rebound to run `picture-move-down' and `picture-move-up', which can either insert spaces or convert tabs as necessary to make sure that point stays in exactly the same column. `C-e' runs `picture-end-of-line', which moves to after the last nonblank character on the line. There is no need to change `C-a', as the choice of screen model does not affect beginnings of lines. Insertion of text is adapted to the quarter-plane screen model through the use of Overwrite mode (*Note Minor Modes::). Self-inserting characters replace existing text, column by column, rather than pushing existing text to the right. RET runs `picture-newline', which just moves to the beginning of the following line so that new text will replace that line. Deletion and killing of text are replaced with erasure. DEL (`picture-backward-clear-column') replaces the preceding character with a space rather than removing it. `C-d' (`picture-clear-column') does the same thing in a forward direction. `C-k' (`picture-clear-line') really kills the contents of lines, but does not ever remove the newlines from the buffer. To do actual insertion, you must use special commands. `C-o' (`picture-open-line') still creates a blank line, but does so after the current line; it never splits a line. `C-M-o', `split-line', makes sense in Picture mode, so it is not changed. LFD (`picture-duplicate-line') inserts below the current line another line with the same contents. Real deletion can be done with `C-w', or with `C-c C-d' (which is defined as `delete-char', as `C-d' is in other modes), or with one of the picture rectangle commands (*Note Rectangles in Picture::). File: emacs Node: Insert in Picture, Prev: Basic Picture, Up: Picture, Next: Tabs in Picture Controlling Motion after Insert =============================== Since "self-inserting" characters in Picture mode just overwrite and move point, there is no essential restriction on how point should be moved. Normally point moves right, but you can specify any of the eight orthogonal or diagonal directions for motion after a "self-inserting" character. This is useful for drawing lines in the buffer. `C-c <' Move left after insertion (`picture-movement-left'). `C-c >' Move right after insertion (`picture-movement-right'). `C-c ^' Move up after insertion (`picture-movement-up'). `C-c .' Move down after insertion (`picture-movement-down'). `C-c `' Move up and left ("northwest") after insertion (`picture-movement-nw'). `C-c '' Move up and right ("northeast") after insertion (`picture-movement-ne'). `C-c /' Move down and left ("southwest") after insertion (`picture-movement-sw'). `C-c \' Move down and right ("southeast") after insertion (`picture-movement-se'). Two motion commands move based on the current Picture insertion direction. The command `C-c C-f' (`picture-motion') moves in the same direction as motion after "insertion" currently does, while `C-c C-b' (`picture-motion-reverse') moves in the opposite direction. File: emacs Node: Tabs in Picture, Prev: Insert in Picture, Up: Picture, Next: Rectangles in Picture Picture Mode Tabs ================= Two kinds of tab-like action are provided in Picture mode. Context-based tabbing is done with `M-TAB' (`picture-tab-search'). With no argument, it moves to a point underneath the next "interesting" character that follows whitespace in the previous nonblank line. "Next" here means "appearing at a horizontal position greater than the one point starts out at". With an argument, as in `C-u M-TAB', this command moves to the next such interesting character in the current line. `M-TAB' does not change the text; it only moves point. "Interesting" characters are defined by the variable `picture-tab-chars', which contains a string whose characters are all considered interesting. Its default value is `"!-~"'. TAB itself runs `picture-tab', which operates based on the current tab stop settings; it is the Picture mode equivalent of `tab-to-tab-stop'. Normally it just moves point, but with a numeric argument it clears the text that it moves over. The context-based and tab-stop-based forms of tabbing are brought together by the command `C-c TAB', `picture-set-tab-stops'. This command sets the tab stops to the positions which `M-TAB' would consider significant in the current line. The use of this command, together with TAB, can get the effect of context-based tabbing. But `M-TAB' is more convenient in the cases where it is sufficient. File: emacs Node: Rectangles in Picture, Prev: Tabs in Picture, Up: Picture Picture Mode Rectangle Commands =============================== Picture mode defines commands for working on rectangular pieces of the text in ways that fit with the quarter-plane model. The standard rectangle commands may also be useful (*Note Rectangles::). `C-c C-k' Clear out the region-rectangle (`picture-clear-rectangle'). With argument, kill it. `C-c C-w R' Similar but save rectangle contents in register R first (`picture-clear-rectangle-to-register'). `C-c C-y' Copy last killed rectangle into the buffer by overwriting, with upper left corner at point (`picture-yank-rectangle'). With argument, insert instead. `C-c C-x R' Similar, but use the rectangle in register R (`picture-yank-rectangle-from-register'). The picture rectangle commands `C-c C-k' (`picture-clear-rectangle') and `C-c C-w' (`picture-clear-rectangle-to-register') differ from the standard rectangle commands in that they normally clear the rectangle instead of deleting it; this is analogous with the way `C-d' is changed in Picture mode. However, deletion of rectangles can be useful in Picture mode, so these commands delete the rectangle if given a numeric argument. The Picture mode commands for yanking rectangles differ from the standard ones in overwriting instead of inserting. This is the same way that Picture mode insertion of other text is different from other modes. `C-c C-y' (`picture-yank-rectangle') inserts (by overwriting) the rectangle that was most recently killed, while `C-c C-x' (`picture-yank-rectangle-from-register') does likewise for the rectangle found in a specified register. File: emacs Node: Sending Mail, Prev: Picture, Up: Top, Next: Rmail Sending Mail ************ To send a message in Emacs, you start by typing a command (`C-x m') to select and initialize the `*mail*' buffer. Then you edit the text and headers of the message in this buffer, and type another command (`C-c C-c') to send the message. `C-x m' Begin composing a message to send (`mail'). `C-x 4 m' Likewise, but display the message in another window (`mail-other-window'). `C-c C-c' In Mail mode, send the message and switch to another buffer (`mail-send-and-exit'). The command `C-x m' (`mail') selects a buffer named `*mail*' and initializes it with the skeleton of an outgoing message. `C-x 4 m' (`mail-other-window') selects the `*mail*' buffer in a different window, leaving the previous current buffer visible. Because the mail composition buffer is an ordinary Emacs buffer, you can switch to other buffers while in the middle of composing mail, and switch back later (or never). If you use the `C-x m' command again when you have been composing another message but have not sent it, you are asked to confirm before the old message is erased. If you answer `n', the `*mail*' buffer is left selected with its old contents, so you can finish the old message and send it. `C-u C-x m' is another way to do this. Sending the message marks the `*mail*' buffer "unmodified", which avoids the need for confirmation when `C-x m' is next used. If you are composing a message in the `*mail*' buffer and want to send another message before finishing the first, rename the `*mail*' buffer using `M-x rename-buffer' (*Note Misc Buffer::). * Menu: * Format: Mail Format. Format of the mail being composed. * Headers: Mail Headers. Details of allowed mail header fields. * Mode: Mail Mode. Special commands for editing mail being composed.