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| author | Alan Hicks <alan@lizella.net> | 2012-09-15 13:28:48 -0400 |
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| committer | Alan Hicks <alan@lizella.net> | 2012-09-15 13:28:48 -0400 |
| commit | 286c073eec3ec0672719f628865523af803d5063 (patch) | |
| tree | 3e48adb704c2d539a2eb57b5f264f10e5575da82 | |
| parent | 56f820b54ea9cec5af68ac810c86b96d147b9a7b (diff) | |
| download | slackbook-286c073eec3ec0672719f628865523af803d5063.tar.xz | |
All new Chapter 13 courtesy of Andrew Psaltis. This chapter needs some
work proofreading and editing.
| -rw-r--r-- | chapter_13.xml | 865 |
1 files changed, 409 insertions, 456 deletions
diff --git a/chapter_13.xml b/chapter_13.xml index 771cb85..fe3305f 100644 --- a/chapter_13.xml +++ b/chapter_13.xml @@ -2,460 +2,413 @@ <!DOCTYPE chapter PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN" "/usr/share/xml/docbook/xml-dtd-4.5/docbookx.dtd"> -<chapter id="ch_emacs"> -<title>Emacs</title> - -<para> -While <application>vi</application> (with its clones) is without a -doubt the most ubiquitous -editor on Unix-like systems, <application>emacs</application>(1) comes -in a good second. Instead of -using different "modes", like <application>vi</application> does, it uses <keycap>CTRL</keycap> and <keycap>ALT</keycap> key -combinations to enter commands, in much the same way that you can use -<keycap>CTRL</keycap> and <keycap>ALT</keycap> key combinations in a word processor and indeed in -many other applications to execute certain functions. (Though it should -be noted that the commands rarely correspond; so while many modern -applications use Ctrl-C/ X/ V for copying, cutting and pasting, <application>emacs</application> -uses different keys and actually a somewhat different mechanism for -this.) -</para> - -<para> -Also unlike <application>vi</application>, which is an (excellent) editor and nothing more, <application>emacs</application> -is a program with near endless capabilities. <application>emacs</application> is (for the most -part) written in Lisp, which is a very powerful programming language -that has the peculiar property that every program written in it is -automatically a Lisp compiler of its own. This means that the user can -extend <application>emacs</application>, and in fact write completely new programs "in <application>emacs</application>". -</para> - -<para> -As a result, <application>emacs</application> is not just an editor anymore. There are many add-on -packages for <application>emacs</application> available (many come with the program's source) that -provide all sorts of functionality. Many of these are related to text -editing, which is after all <application>emacs</application>' basic task, but it doesn't stop -there. There are for example several spreadsheet programs for <application>emacs</application>, -there are databases, games, mail and news clients (the top one being -Gnus), etc. -</para> - -<para> -There are two main versions of <application>emacs</application>: GNU Emacs (which is the version -that comes with Slackware) and XEmacs. The latter is not a version for -Emacs running under X. In fact, both <application>emacs</application> and XEmacs run on the -console as well as under X. XEmacs was once started as a project to -tidy up the <application>emacs</application> code. Currently, both versions are being actively -developed, and there is in fact much interaction between the two -development teams. For the present chapter, it is immaterial whether -you use <application>emacs</application> or XEmacs, the differences between them are not relevant -to the normal user. -</para> - -<section id="emacs_starting-emacs"> -<title>Starting Emacs</title> - -<para> -Emacs can be started from the shell by simply typing <application>emacs</application>. When you -are running X, <application>emacs</application> will (normally) come up with its own X window, -usually with a menu bar at the top, where you can find the most -important functions. On startup, <application>emacs</application> will first show a welcome -message, and then after a few seconds will drop you in the *scratch* -buffer. (See Section 17.2.) -</para> - -<para> -You can also start <application>emacs</application> on an existing file by typing -</para> - -<screen> - <prompt>% </prompt> <command><application>emacs</application> - <filename>/etc/resolv.conf</filename> - </command> -</screen> - -<para> -This will cause <application>emacs</application> to load the specified file when it starts up, -skipping the welcome message. -</para> - -<section id="emacs_command-keys"> -<title>Command Keys</title> -<para> -As mentioned above, <application>emacs</application> uses <keycap>CTRL</keycap> and <keycap>ALT</keycap> combinations for -commands. The usual convention is to write these with <keycap>C</keycap>-letter and -<keycap>M</keycap>-letter, respectively. So <keycap>C</keycap>-x means <keycap>CTRL</keycap>+x, and <keycap>M</keycap>-x means <keycap>ALT</keycap>+x. -</para> - -<note> - <para> - The letter M is used instead of A because originally the key was not -the <keycap>ALT</keycap> key but the Meta key. The Meta key has all but disappeared from -computer keyboards, and in <application>emacs</application> the <keycap>ALT</keycap> key has taken over its -function. - </para> -</note> - -<para> -Many <application>emacs</application> commands consist of sequences of keys and key combinations. -For example, <keycap>C</keycap>-x <keycap>C</keycap>-c (that is <keycap>CTRL</keycap>-x followed by <keycap>CTRL</keycap>-c) quits -Emacs, <keycap>C</keycap>-x <keycap>C</keycap>-s saves the current file. Keep in mind that <keycap>C</keycap>-x <keycap>C</keycap>-b is not -the same as <keycap>C</keycap>-x b. The former means <keycap>CTRL</keycap>-x followed by <keycap>CTRL</keycap>-b, -while the latter means <keycap>CTRL</keycap>-x followed by just 'b'. -</para> - -</section> - -</section> - -<section id="emacs_buffers"> -<title>Buffers</title> -<para> -In <application>emacs</application>, the concept of 'buffers' is essential. Every file that you -open is loaded into its own buffer. Furthermore, <application>emacs</application> has several -special buffers, which do not contain a file but are used for other -things. Such special buffers usually have a name that starts and ends -with an asterisk. For example, the buffer that <application>emacs</application> shows when it is -first started, is the so-called *scratch* buffer. In the *scratch* -buffer, you can type text in the normal way, but text that is typed -there is not saved when <application>emacs</application> is closed. -</para> -<para> -There is one other special buffer you need to know about, and that is -the minibuffer. This buffer consists of only one line, and is always on -the screen: it is the very last line of the <application>emacs</application> window, below the -status bar for the current buffer. The minibuffer is where <application>emacs</application> shows -messages for the user, and it is also the place where commands that -require some user input are executed. For example, when you open a -file, <application>emacs</application> will ask for its name in the minibuffer. -</para> -<para> -Switching from one buffer to another can be done with the command <keycap>C</keycap>-x -b. This will prompt you for the name of a buffer (a buffer's name is -usually the name of the file you are editing in it), and it gives a -default choice, which is normally the buffer that you were in before -you switched to or created the current buffer. Just hitting Enter will -switch to that default buffer. -</para> -<para> -If you want to switch to another buffer than the default offered by -Emacs, just type its name. Note that you can use so-called -Tab-completion here: type the first few letters of the buffer's name -and hit Tab; <application>emacs</application> will then complete the name of the buffer. Tab -completion works everywhere in <application>emacs</application> where it makes sense. -</para> -<para> -You can get a list of open buffers by hitting <keycap>C</keycap>-x <keycap>C</keycap>-b. This command -will usually split the screen in two, displaying the buffer you were -working in in the top half, and a new buffer called *Buffer List* in -the bottom half. This buffer contains a list of all the buffers, their -sizes and modes, and the files, if any, that those buffers are visiting -(as it is called in <application>emacs</application>). You can get rid of this split screen by -typing <keycap>C</keycap>-x 1. -</para> -</section> - -<section id="emacs_modes"> -<title>Modes</title> -<para> -Every buffer in <application>emacs</application> has an associated mode. This mode is very -different from the idea of modes in <application>vi</application>: a mode tells you what kind of -buffer you are in. For example, there is text-mode for normal text -files, but there are also modes such as c-mode for editing C programs, -sh-mode for editing shell scripts, latex-mode for editing LaTeX files, -mail-mode for editing email and news messages, etc. A mode provides -special customizations and functionality that is useful for the kind of -file you are editing. It is even possible for a mode to redefine keys -and key commands. For example, in Text mode, the <keycap>Tab</keycap> key simply jumps -to the next tab stop, but in many programming language modes, the <keycap>Tab</keycap> -key indents the current line according to the depth of the block that -line is in. -</para> - -<para> -The modes mentioned above are called <emphasis>major modes</emphasis>. Each buffer has -exactly one major mode. Additionally, a buffer can have one or more -minor modes. A <emphasis>minor mode</emphasis> provides additional features that may be -useful for certain editing tasks. For example, if you hit the <keycap>INSERT</keycap> -key, you invoke overwrite-mode, which does what you'd expect. There is -also an auto-fill-mode, which is handy in combination with text-mode or -latex-mode: it causes each line that you type to be automatically -wrapped once the line reaches a certain number of characters. Without -auto-fill-mode, you have to type <keycap>M</keycap>-q to fill out a paragraph. (Which -you can also use to reformat a paragraph after you've edited some text -in it and it is no longer nicely filled out.) -</para> - -<section id="emacs_opening-files"> -<title>Opening Files</title> - -<para> -To open a file in <application>emacs</application>, type <keycap>C</keycap>-x <keycap>C</keycap>-f -</para> - -<para> -<application>Emacs</application> will ask you for the name of the file, filling in some default -path for you (which is usually ~/ ). After you type the filename (you -can use <keycap>Tab</keycap> completion) and hit <keycap>ENTER</keycap>, <application>emacs</application> will open the file in a -new buffer and display that buffer on the screen. -</para> - -<note> - <para> - <application>Emacs</application> will automatically create a new - buffer, it will not load the file into the current buffer. - </para> -</note> - - <para> - In order to create a new file in <application>emacs</application>, - you cannot just go typing right away. You first have to create a - buffer for it, and come up with a filename. You do this by typing - <keycap>C</keycap>-x <keycap>C</keycap>-f and typing a filename, - just as if you were opening an existing - file. <application>Emacs</application> will notice that the file - you typed doesn't exist, and will create a new buffer and report - "(New file)" in the minibuffer. - </para> - - <para> -When you type <keycap>C</keycap>-x <keycap>C</keycap>-f and then enter a directory name instead of a -filename, <application>emacs</application> will create a new buffer in which you will find a list -of all the files in that directory. You can move the cursor to the file -that you are looking for and type , and -<application>emacs</application> will open it. - </para> - -<note> - <para> - There are in fact a lot more actions you can perform here, such as - deleting, renaming and moving files, - and so on. This is the dired-mode of <application>emacs</application>, which - is basically a simple file manager. - </para> -</note> - -<para> -When you have typed <keycap>C</keycap>-x <keycap>C</keycap>-f and suddenly change your mind, you can type -<keycap>C</keycap>-g to cancel the action. <keycap>C</keycap>-g works almost everywhere where you want to -cancel an action or command that you've started but don't want to -finish. -</para> -</section> <!-- closing OPENING FILES section --> - -</section> <!-- closing MODES section --> - -<section id="emacs_basic-editing"> -<title>Basic Editing</title> - -<para> -When you have opened a file, you can of course move around in it with -the cursor. The cursor keys and <keycap>PgUp</keycap>, <keycap>PgDn</keycap> do what you'd expect. <keycap>Home</keycap> -and <keycap>End</keycap> jump to the beginning and end of the line. (In older versions, -they would actually jump to the beginning and end of the buffer.) -However, there are also <keycap>CTRL</keycap> and Meta (<keycap>ALT</keycap>) key combos that move the -cursor around. Because you do not need to move your hands to another -part of the keyboard for these, they are much quicker once you get used -to them. -</para> - -<table> -<title>Basic <application>emacs</application> Editing Commands</title> -<tgroup cols="2"> - <thead> - <row> - <entry>Command</entry> - <entry>Result</entry> - </row> - </thead> - <tbody> - <row> - <entry><keycap>C</keycap>-b</entry> - <entry>go one character back</entry> - </row> - <row> - <entry><keycap>C</keycap>-f</entry> - <entry>go one character forward</entry> - </row> - <row> - <entry><keycap>C</keycap>-n</entry> - <entry>go one line down</entry> - </row> - <row> - <entry><keycap>C</keycap>-p</entry> - <entry>go one line up</entry> - </row> - <row> - <entry><keycap>C</keycap>-a</entry> - <entry>go to the beginning of the line</entry> - </row> - <row> - <entry><keycap>C</keycap>-e</entry> - <entry>go to the end of the line</entry> - </row> - <row> - <entry><keycap>M</keycap>-b</entry> - <entry>go one word back</entry> - </row> - <row> - <entry><keycap>M</keycap>-f</entry> - <entry>go one word forward</entry> - </row> - <row> - <entry><keycap>M</keycap>-}</entry> - <entry>go one paragraph forward</entry> - </row> - <row> - <entry><keycap>M</keycap>-{</entry> - <entry>go one paragraph backward</entry> - </row> - <row> - <entry><keycap>M</keycap>-a</entry> - <entry>go one sentence backward</entry> - </row> - <row> - <entry><keycap>M</keycap>-e</entry> - <entry>go one sentence forward</entry> - </row> - <row> - <entry><keycap>C</keycap>-d</entry> - <entry>delete the character under the cursor</entry> - </row> - <row> - <entry><keycap>M</keycap>-d</entry> - <entry>delete until the end of the current word</entry> - </row> - <row> - <entry><keycap>C</keycap>-v</entry> - <entry>go down one screen (i.e., - <keycap>PgDn</keycap>)</entry> - </row> - <row> - <entry><keycap>M</keycap>-v</entry> - <entry>go up one screen (i.e., - <keycap>PgUp</keycap>)</entry> - </row> - <row> - <entry><keycap>M</keycap>-<</entry> - <entry>go to the beginning of the buffer</entry> - </row> - <row> - <entry><keycap>M</keycap>-></entry> - <entry>go to the end of the buffer</entry> - </row> - <row> - <entry><keycap>C</keycap>-_</entry> - <entry>undo the last change (can be repeated); note - that you actually have to type - <keycap>SHIFT</keycap>+<keycap>CTRL</keycap>+hyphen for this. - </entry> - </row> - <row> - <entry><keycap>C</keycap>-k</entry> - <entry>delete to end of line</entry> - </row> - <row> - <entry><keycap>C</keycap>-s</entry> - <entry>forward search</entry> - </row> - <row> - <entry><keycap>C</keycap>-r</entry> - <entry>reverse search</entry> - </row> - </tbody> -</tgroup> -</table> - -<para> -Note that many Meta commands are parallel to the <keycap>CTRL</keycap> commands -except that they operate on larger units: while <keycap>C</keycap>-f goes forward one -character, <keycap>M</keycap>-f goes forward an entire word, etc. -</para> - -<para> -Also note that <keycap>M</keycap>-< and <keycap>M</keycap>-> require you to type <keycap>SHIFT</keycap>+<keycap>ALT</keycap>+comma and -<keycap>SHIFT</keycap>+<keycap>ALT</keycap>+dot respectively, since -< and > are on <keycap>SHIFT</keycap>+comma and -<keycap>SHIFT</keycap>+dot. (Unless of course you have a different keyboard layout from -the standard US layout.) -</para> - -<para> -Note that <keycap>C</keycap>-k deletes (kills, as it is commonly called) all the text -after the cursor to the end of the line, but doesn't delete the line -itself (i.e., it doesn't delete the final newline). It only deletes the -line if there was no text after the cursor. In other words, in order to -delete a complete line, you have to put the cursor at the beginning of -the line, and then hit <keycap>C</keycap>-k twice: once to delete the text on the line, -and once to delete the line itself. -</para> - -</section> <!-- closing EDITING section --> - -<section id="emacs_saving-files"> -<title>Saving Files</title> - -<para> -In order to save a file, you type <keycap>C</keycap>-x <keycap>C</keycap>-s -</para> - -<para> -<application>Emacs</application> will not ask you for a filename, the buffer will just be saved to -the file it was loaded from. If you want to save your text to another -file, type - -<keycap>C</keycap>-x <keycap>C</keycap>-w -</para> - -<para> -When you save the file for the first time in this session, <application>emacs</application> will -normally save the old version of your file to a backup file, which has -the same name appended with a tilde: so if you're editing a file -<filename>cars.txt</filename>, <application>emacs</application> will create a backup <filename>cars.txt~</filename>. -</para> - -<para> -This backup file is a copy of the file that you opened. While you are -working, <application>emacs</application> will also regularly create an auto-save copy of the work -you are doing, to a file named with hash signs: #cars.txt#. This backup -is deleted when you save the file with <keycap>C</keycap>-x <keycap>C</keycap>-s. -</para> - -<para> -When you are done editing a file, you can kill the buffer that holds it -by typing <keycap>C</keycap>-x k -</para> - -<para> -<application>Emacs</application> will then ask you which buffer you want to kill, with the current -buffer as default, which you can select by hitting <keycap>ENTER</keycap>. If you -haven't saved your file yet, <application>emacs</application> will ask you if you really want to -kill the buffer. -</para> - -<para> - If you'd prefer to save the file with a new name so that you - don't overwrite the original version, use <keycap>C</keycap>-x - <keycap>C</keycap>-w instead. You may then give a new name for the - file, and the buffer will be updated to reflect the contents of this - new file, leaving the old file unchanged. -</para> - -</section> - -<section id="emacs_quitting-emacs"> -<title>Quitting Emacs</title> - -<para> -When you are done with <application>emacs</application> altogether, -you can type <keycap>C</keycap>-x <keycap>C</keycap>-c -</para> - -<para> -This quits <application>emacs</application>. If you have any unsaved files, <application>emacs</application> will tell you -so, and ask if you want to save them each in turn. If you answer no to -any of these, <application>emacs</application> will ask for one final confirmation and then quit. -</para> - -</section> <!-- closing QUIT section --> - +<chapter> + <title><application>Emacs</application></title> + + <section> + <title>What is <application>Emacs</application>?</title> + + <para> + <application>vi</application> and its clones are very functional + and powerful editors. However, they are often considered not + particularly extensible. <application>vim</application> is a + successful and powerful + <application>vi</application> variant that shrugs this trend, + being both extremely extensible and lightweight. However, many + users prefer a more "heavy" and extensible editor. This is why + many people (including the author of this chapter) prefer + <application>Emacs</application>. + </para> + + <para> + Emacs takes extensibility up to eleven. Outside of a core of C, + the rest of <application>Emacs</application> is written in a + Lisp variant, nearly all of which is exposed to you, so that you + may configure it or even extend it at will (many good Emacs Lisp + tutorials can be found on the Internet). People have written + all sorts of extensions in Emacs Lisp, from syntax highlighting + for an obscure language, to a built-in terminal. In fact, + there's even a <application>vi</application> emulation mode + within <application>Emacs</application> (called viper), so you + can still get the modal editing that comes with vi, while having + access to the power of the <application>Emacs</application> + core. + </para> + + <para> + Like <application>vi</application>, there are many variants of + <application>Emacs</application> (termed "emacsen"). However, + the one most commonly used (and the only one in Slackware) is + GNU Emacs. When people reference "Emacs" directly, they almost + always mean GNU Emacs. + </para> + + <para> + Unlike <application>vi</application>, + <application>Emacs</application> operates more like a + traditional editor by default. This means that most keyboard + shortcuts can be performed without repeatedly changing modes. + You can open up a file and start typing away without having to + learn what the modes do, or forgetting which one you are + currently using. + </para> + </section> + + <section> + <title>Starting Out</title> + <para> + <application>Emacs</application> can be started simply by + running the <application>emacs</application> command in your + terminal. When + you first start it in a console without arguments, you will see + something that resembles this: + </para> + + <imagedata fileref="img/emacs-startup.png" format="PNG"/> + + <para> + If you are in X windows, <application>Emacs</application> may + start a GUI instead of running in your console. If this is the + case and you don't want a GUI, you can invoke it with the flag + <arg>'-nw'</arg>. + </para> + + <para> + While here, you can browse around using the + keyboard arrow keys. + Underlined elements are links, and you can activate them by + moving over them and pressing 'enter'. The documentation + mentioned is very good, and can help you get your bearings + should you have any problems. Also note how they describe key + sequences such as <keycap>C-h</keycap>, meaning press the + <keycap>h</keycap> + key while holding down the <keycap>CTRL</keycap> key. Same deal + with <keycap>M-`</keycap>, meaning to hold the the + <keycap>Meta</keycap> key (usually "<keycap>Alt</keycap>") and + press the backtick "`" key. When they say (e.g.) <keycap>C-x + C-c</keycap>, this means to press the "x" key while holding down + the <keycap>CTRL</keycap> key, then press the "x" key while also + holding down the <keycap>CTRL</keycap> key. Conveniently, this + is also one of the more important commands in + <application>Emacs</application>: to close it. + </para> + + <para> + Alternatively, if you call <application>emacs</application> with a + file name as an argument, it will open that file, just like + <application>vi</application>. Upon doing this, you will be + presented with the contents of the file in question. Here, you can + navigate the document using traditional arrow keys and type in + information at will without any issues. + </para> + + <para> + Say you make some edits, and you now want to save your file. + The following key sequence will do that: <keycap>C-x C-s</keycap>. + If you made a new file, you will be prompted for this in what is + called the "minibuffer", the blank line below the gray line at + the bottom of the screen. Type in the file name of your choice, + then hit <keycap>Enter</keycap>. If you don't want to + save the file, you can press <keycap>C-g</keycap>, which aborts + operations that ask for input. Do note that tab-completion is + usually available for operations that use the minibuffer. + </para> + + <para> + Should you want to open a new file within your same + <application>Emacs</application> session, type in <keycap>C-x + C-f</keycap>. You will be prompted for a file name in the + minibuffer. <application>Emacs</application> doesn't care + whether it exists or not. If it doesn't exist, a new buffer + will be created for it (the file will be created upon saving + with <keycap>C-x C-s</keycap>), or it will be opened as + expected. However, the old file will still be open! You can + switch back to it using <keycap>C-x C-b</keycap>, entering in + the file's name (or more technically, the buffer's name), then + hitting <keycap>Enter</keycap>. + </para> + + </section> + + <section> + <title>How to Move Around</title> + <para> + Like <application>vi</application>, + <application>Emacs</application> is also older than the arrow + keys on your keyboard. Also, like in + <application>vi</application>, using the arrow keys to navigate + files is also supported. While the + <application>vi</application> movement keys are more ergonomic, + <application>emacs</application>'s are more "mnemonic". + However, it is still very possible to operate using the main + <application>Emacs</application> keybindings quickly and + efficiently. Here is a table of the basic movement keybindings: + </para> + + <table pgwide="0"> + <title>Emacs Cursor Movement</title> + <tgroup cols="2"> + <thead> + <row> + <entry>Command</entry> + <entry>Result</entry> + </row> + </thead> + <tbody> + <row> + <entry>C-f</entry> + <entry>Move the cursor one character to the right (forward)</entry> + </row> + <row> + <entry>C-b</entry> + <entry>Move the cursor one character to the left (backward)</entry> + </row> + <row> + <entry>C-n</entry> + <entry>Move the cursor one line down (next)</entry> + </row> + <row> + <entry>C-p</entry> + <entry>Move the cursor one line up (previous)</entry> + </row> + </tbody> + </tgroup> + </table> + + <para> + Of course, like with <application>vi</application> it is also + possible to repeat these commands with a numeric argument. If you + type in <keycap>M-1 M-0 C-p</keycap>, or <keycap>C-u 10 + C-p</keycap>, the cursor will move ten lines up. If you type in + <keycap>M-5 C-f</keycap> or <keycap>C-u 5 C-f</keycap>, the cursor + will move five characters to the right. + </para> + </section> + + <section> + <title>Getting Help</title> + + <para> + <application>Emacs</application> contains a great deal of + documentation, to the point that it is often called a + "self-documenting" editor. This is because it provides + mechanisms for providing users with documentation while you are + using it. + + Here are some useful functions that display documentation (they + all start with <keycap>C-h</keycap>): + </para> + + <table pgwide="0"> + <title>Accessing <application>Emacs</application> Documentation</title> + <tgroup cols="2"> + <thead> + <row> + <entry>Command</entry> + <entry>Result</entry> + </row> + </thead> + <tbody> + <row> + <entry>C-h f FUNCTION-NAME Enter</entry> + <entry>Show documentation for function FUNCTION-NAME</entry> + </row> + <row> + <entry>C-h k C-x C-c</entry> + <entry>Show documentation for the function bound to the keys + <keycap>C-x C-c</keycap></entry> + </row> + <row> + <entry>C-h t</entry> + <entry>Show the Emacs tutorial</entry> + </row> + <row> + <entry>C-h ?</entry> + <entry>Show all help-related functions</entry> + </row> + </tbody> + </tgroup> + </table> + <para> + <keycap>C-h t</keycap> is especially useful if + you want or need practice using <application>Emacs</application>. + </para> + + </section> + + + <section> + <title>Calling Functions</title> + <para> + As noted earlier, <application>Emacs</application> exports a + large number of functions to for interactive use. Some of + these, like those opening and saving files, are mapped to keys. + Others (like the ones for moving to the beginning and end of + lines) are not. To call them, you have to invoke them. Say we + want to call the function "end-of-line". We would do + this: + </para> + + <para> + <keycap>M-x end-of-line Enter</keycap> + </para> + + <para> + And the cursor would move to the end of the line, as the function name + suggests. + </para> + </section> + + <section> + <title>Emacs Cheat Sheet</title> + + <para> + While Emacs can be simple to use, its scope can easily be + overwhelming. Below are some useful Emacs commands. Some + aspects have been simplified, most notably regarding text + selection. These concepts, and more, are described the + <application>Emacs</application> manual, and various on-line + tutorials. Decent summaries can also be gleaned from web + searches. + </para> + + <table pgwide="0"> + <title>Emacs Cheat Sheet</title> + <tgroup cols="2"> + <thead> + <row> + <entry>Command</entry> + <entry>Result</entry> + </row> + </thead> + <tbody> + <row> + <entry>C-f</entry> + <entry>Move the cursor one character to the right (forward)</entry> + </row> + <row> + <entry>C-b</entry> + <entry>Move the cursor one character to the left (backward)</entry> + </row> + <row> + <entry>C-n</entry> + <entry>Move the cursor one line down (next)</entry> + </row> + <row> + <entry>C-p</entry> + <entry>Move the cursor one line up (previous)</entry> + </row> + <row> + <entry>C-h f FUNCTION-NAME Enter</entry> + <entry>Show documentation for function FUNCTION-NAME</entry> + </row> + <row> + <entry>C-h k C-x C-c</entry> + <entry>Show documentation for the function bound to the keys <keycap>C-x C-c</keycap></entry> + </row> + <row> + <entry>C-h t</entry> + <entry>Show the Emacs tutorial</entry> + </row> + <row> + <entry>C-h ?</entry> + <entry>Show all help-related functions</entry> + </row> + <row> + <entry>M-`</entry> + <entry>Access the Menu Bar</entry> + </row> + <row> + <entry>C-g</entry> + <entry>Cancel the current operation. This is most useful when in the minibuffer.</entry> + </row> + <row> + <entry>M-x FUNCTION-NAME Enter</entry> + <entry>Call the interactive function FUNCTION-NAME</entry> + </row> + <row> + <entry>M-1 M-0 C-n</entry> + <entry>Move the cursor ten lines down</entry> + </row> + <row> + <entry>C-u 10 C-n</entry> + <entry>Move the cursor ten lines down (same as above)</entry> + </row> + <row> + <entry>M-x beginning-of-line</entry> + <entry>Move the cursor to the beginning of the current line</entry> + </row> + <row> + <entry>M-x end-of-line</entry> + <entry>Move the cursor to the end of the current line</entry> + </row> + <row> + <entry>M-></entry> + <entry>Move the cursor to the end of the buffer</entry> + </row> + <row> + <entry>M-<</entry> + <entry>Move the cursor to the beginning of the buffer</entry> + </row> + <row> + <entry>C-k</entry> + <entry>Remove text from the cursor to the end of the line and + place it into the kill ring </entry> + </row> + <row> + <entry>C-space</entry> + <entry>Enter selection mode (use normal motion keys to move around). Press <keycap>C-space</keycap> again to leave it.</entry> + </row> + <row> + <entry>C-w</entry> + <entry>While in selection mode, delete the selected region, and store the result into the kill ring</entry> + </row> + <row> + <entry>M-w</entry> + <entry>While in selection mode, store the selected region into the kill ring.</entry> + </row> + <row> + <entry>C-y</entry> + <entry>"Yanks" the contents of the kill ring and places them at the cursor's location</entry> + </row> + <!-- <row> + <entry>M-y</entry> + <entry>Replace the current contents of the kill ring with the item last yanked from it. Useful for cycling between the key-ring </entry> + </row> --> + <row> + <entry>C-/</entry> + <entry>Undo the previous action. Unlike most other editors, this includes previous undo actions.</entry> + </row> + <row> + <entry>insert</entry> + <entry>Enable or disable overwriting characters</entry> + </row> + <row> + <entry>C-s asdf Enter</entry> + <entry>Forward incremental search for the string "asdf". Repeat <keycap>C-s</keycap> as needed to search for future items, or <keycap>C-r</keycap> (below) to search backwards.</entry> + </row> + <row> + <entry>C-r asdf Enter</entry> + <entry>Backward incremental search for the string "asdf". Repeat <keycap>C-r</keycap> as needed to search for future items, or <keycap>C-s</keycap> (above) to search forwards.</entry> + </row> + <row> + <entry>M-% old Enter new Enter</entry> + <entry>Search for each instance of "old" and prompt you to replace it with "new". You can force replacement of all items by typing "!" at the replacement prompt. </entry> + </row> + <row> + <entry>C-x C-c</entry> + <entry>Exit <application>Emacs</application>, prompting you to save each unsaved buffer before doing so</entry> + </row> + <row> + <entry>C-x C-s</entry> + <entry>Save the currrent buffer to its file</entry> + </row> + <row> + <entry>C-x C-w new-file.txt Enter</entry> + <entry>Save the current buffer to a file "new-file.txt"</entry> + </row> + </tbody> + </tgroup> + </table> + </section> </chapter> |