Annotation of src/usr.bin/mg/tutorial, Revision 1.7
1.7 ! lum 1: $Id: tutorial,v 1.6 2011/09/02 02:37:52 lum Exp $
1.1 deraadt 2:
1.5 kjell 3: The mg Tutorial
4: ---------------
1.1 deraadt 5:
1.5 kjell 6: The mg editor is a public domain editor intended to loosely resemble GNU Emacs,
7: while still retaining fast speed and a small memory footprint.
1.1 deraadt 8:
1.5 kjell 9: Most mg commands involve using the Control (sometimes labelled "Ctrl") or the
10: Meta (sometimes labelled "Alt") key. We will use the following conventions in
11: this tutorial:
1.1 deraadt 12:
1.5 kjell 13: C-<chr> means hold down the Control key while typing the character <chr>.
14: M-<chr> means hold down the Meta key while typing the character <chr>.
1.1 deraadt 15:
1.5 kjell 16: If you don't have a Meta key, you can use Esc instead. Press and release the
17: Esc key and type <chr>. This is equivalent to M-<chr>.
1.1 deraadt 18:
1.5 kjell 19: The first thing to learn is how to move up and down a document. To move your
20: cursor down, use the down-arrow cursor key or C-n (Control and n)
1.1 deraadt 21:
1.5 kjell 22: >> Now type C-n multiple times and move your cursor past this line.
1.1 deraadt 23:
1.5 kjell 24: Congratulations. You have now learned how to move your cursor down. Note how
25: mg has redrawn your screen so that the cursor is now in the middle of the
26: screen. This is a feature of mg, which allows you to see the lines before and
27: after the current cursor position.
1.1 deraadt 28:
1.5 kjell 29: To move your cursor up, you can use the up-arrow cursor key or C-p (Control and
30: p).
1.1 deraadt 31:
1.5 kjell 32: >> Try using C-p and C-n to move up and down and then move past this line.
1.1 deraadt 33:
1.5 kjell 34: The next commands to learn are how to move your cursor left and right. To do
35: this, you can use the left-arrow and right-arrow cursor keys. Alternatively,
36: you can use C-b and C-f to do this.
1.1 deraadt 37:
1.5 kjell 38: >> Practise using the arrow keys or C-b and C-f on this line.
1.1 deraadt 39:
1.5 kjell 40: To make it easy to remember these commands, it helps to remember by letter:
41: P - Previous line, N - Next line, B - Backwards and F - Forward.
1.1 deraadt 42:
1.5 kjell 43: Now that you've learned how to move single characters at a time, next we learn
44: how to move one word at a time. To do this, you can use M-f (Meta and f) or
45: M-b (Meta and b) to move forwards and backwards, one word at a time.
1.1 deraadt 46:
1.5 kjell 47: >> Try moving one word at a time by using M-f and M-b on this line.
1.1 deraadt 48:
1.5 kjell 49: Notice how the Ctrl and Meta key combinations perform related functions. C-f
50: moves one letter forward, whereas M-f moves one word forward. There are many
51: key combinations in mg, where C-<chr> will perform one function and M-<chr>
52: will perform a similar related function.
1.1 deraadt 53:
1.5 kjell 54: Next, we will learn how to refresh and redraw the screen.
1.1 deraadt 55:
1.5 kjell 56: >> Now move the cursor down to this line and then type C-l (that's Control and
57: lowercase L) to refresh the screen.
1.1 deraadt 58:
1.5 kjell 59: Note that C-l refreshes the screen and centers it on the line you typed it on.
1.1 deraadt 60:
1.5 kjell 61: To move to the beginning or end of a line, you can use the Home and End keys,
62: or you can use C-a and C-e to move to the beginning and end.
1.1 deraadt 63:
1.5 kjell 64: >> Use C-a and C-e to move to the beginning and end of this line.
1.1 deraadt 65:
1.5 kjell 66: The next commands we will learn is how to move up and down, one page at a time.
67: To do this, you can use the Page Up (sometimes labelled PgUp) and Page Down
68: (sometimes labelled PgDn) keys. You can also use C-v and M-v to do this. C-v
69: moves the cursor down one page and M-v moves it up one page.
1.2 mickey 70:
1.5 kjell 71: >> Try using M-v and C-v to move up and down, one page at a time.
1.1 deraadt 72:
1.5 kjell 73: The final two motion commands we will learn are M-< (Meta-Less than) and
1.7 ! lum 74: M-> (Meta-Greater than) which move you to the beginning and end of a file,
! 75: respectively. You may not want to try that now as you will probably lose your
! 76: place in this tutorial. Note that on most terminals, < is above the , key, so
! 77: you'll need to press the Shift key to type <.
1.1 deraadt 78:
1.5 kjell 79: Movement Summary
1.1 deraadt 80: -----------------
81:
1.5 kjell 82: The following is a summary of the movement commands we've learned so far:
1.1 deraadt 83:
1.5 kjell 84: C-f Move forward one character (can also use right arrow key)
85: C-b Move backward one character (can also use left arrow key)
86: C-p Move up one line (can also use up arrow key)
87: C-n Move down one line (can also use down arrow key)
88: M-f Move forward one word
89: M-b Move backward one word
90: C-a Move to beginning of line (can also use Home key)
91: C-e Move to end of line (can also use End key)
92: C-v Move forward one page (can also use PgDn/Page Down key)
93: M-v Move backward one page (can also use PgUp/Page Up key)
94: M-< Move to beginning of file
95: M-> Move to end of file.
96:
97: Now that you've mastered the basics of moving around in mg, you can cause mg
98: to execute these commands multiple times. The way to do this is to type
99: C-u followed by some digits followed by a movement command.
100:
101: >> Type C-u 5 C-f to move forward 5 characters.
102:
103: In general, C-u allows you to execute any command multiple times, not just
104: cursor motion commands. The only exception to this rule are C-v and M-v.
105: When using these two commands with an argument, they move the cursor by that
106: many lines instead of pages.
1.1 deraadt 107:
1.5 kjell 108: Cancelling mg commands
1.1 deraadt 109: ----------------------
110:
1.5 kjell 111: If you have started typing out a command that you didn't mean to finish, you
112: can use the C-g command to cancel the command immediately.
1.1 deraadt 113:
1.5 kjell 114: >> For example, type C-u 50 and then type C-g to cancel the C-u command.
115: >> Type Esc and then C-g to cancel the Esc key.
1.1 deraadt 116:
1.5 kjell 117: In general, you can use C-g to stop any mg commands. You may type it multiple
118: times if you wish. You should see the word "Quit" appear in the bottom of the
119: screen when you type C-g indicating that a command was cancelled.
1.1 deraadt 120:
1.5 kjell 121: In general, when in doubt, use C-g to get out of trouble.
1.1 deraadt 122:
1.5 kjell 123: Windows
124: -------
1.1 deraadt 125:
1.5 kjell 126: The mg editor can support several windows at the same time, each one displaying
127: different text. To split a screen into two horizontal windows use C-x 2 to do
128: this. To return to one window, use C-x 1 to close the other windows and only
129: keep the current window.
130:
131: >> Use C-x 2 to split the screen into two windows.
132:
133: >> Use C-x o to move from one window to the other. You can scroll up and down
134: in each window using the cursor keys or C-n and C-p keys.
135:
136: >> Use C-x 1 to restore back to one window.
137:
138: Inserting/Deleting Text
139: -----------------------
140:
141: To insert text anywhere, simply move your cursor to the appropriate position
142: and begin typing. To delete characters, use the backspace key. If you use
1.7 ! lum 143: M-<backspace> (Meta and backspace key), you will delete one word instead
1.5 kjell 144: of one character at a time.
145:
146: To delete characters to the right of the cursor, you can use C-d to delete
147: characters to the right of the current position. If you use M-d instead of
148: C-d, you can delete one word at a time instead of one character at a time.
149:
150: >> Try inserting and deleting characters and words on this line.
151:
152: Note that if you type too many characters on a single line, the line will
153: scroll off the screen and you will see a $ on the line to indicate that the
154: line is too long to fit on the screen at one time.
155:
156: To delete a line at a time, you can use C-k to kill the line from the current
157: cursor position to the end of the line. You can type C-k multiple times to
158: kill many lines.
159:
160: You can issue insert or delete commands multiple times using C-u. For example,
161: C-u 10 e will type out eeeeeeeeee, C-u 4 M-d will delete four words to the
162: right of the cursor and so on.
163:
164: To undo any operation, you can use C-_ (That's control-underscore).
165:
166: Now if you kill something that you didn't mean to, you can yank it back from
167: the dead by using C-y. In general, when you kill something bigger than a single
168: character, mg saves it in a buffer somewhere and you can restore it by using
169: C-y. This is useful for moving text around. You can kill text in one place,
170: move your cursor to the new location and then use C-y to paste it there.
171:
172: Search for Text
173: ---------------
174:
175: To search for text, type C-s followed by the text you wish to search for. Note
176: that as you start typing the characters, mg automatically searches as you type
177: the characters.
178:
179: To continue searching the text you're looking for, type C-s to find the next
180: instance. To search in reverse, type C-r instead of C-s. If you type C-s or
181: C-r twice, it will simply search for the last text that you searched for.
182:
183: To stop searching for text, simply use the cursor keys (or C-f, C-b etc.) or
184: C-g to stop the search operation.
185:
186: >> Use C-s foo to search for "foo" in the text. You can use C-s again to
187: find other instances of foo in the file.
188:
189: Note that if a word cannot be found, it will say Failing I-search: at the
190: bottom of the screen. Typing C-s again will wrap the search around from the
191: top of the file and begin searching from there.
192:
193: Replace Text
194: ------------
195:
196: To replace text, use M-%. You will be prompted for the text to search for and
197: the text to replace it with. You will then be taken to the first instance of
198: text from the current position. At this point you can do one of the following:
199:
200: y - Replace the text at this instance and search for more items
201: n - Skip this instance and search for more items
202: . or Enter - Stop replacing text (You can also use C-g)
203: ! - Replace all the instances without prompting at each one.
204:
205: >> Try replacing "frobnitz" with "zutwalt" on this line.
206:
207: Cut/Copy/Paste Text
208: -------------------
209:
210: As explained above, you can cut regions using C-k to kill multiple lines. To
211: paste the text that you just cut, simply move your cursor to the point and
212: then type C-y to restore the text. You may type C-y multiple times to restore
213: the text. Hence, to copy text, you can use C-k to kill all the lines, use C-y
214: to restore it immediately, then move to the region you want to copy it to and
215: then type C-y again to restore the last cut text block again.
216:
217: Another way to cut or copy chunks of text is to first position your cursor at
1.7 ! lum 218: the starting point of the chunk of text. Then type C-<space> to mark this as
! 219: the starting point to cut or copy. Then move the cursor to the end point of the
1.5 kjell 220: text chunk that you wish to manipulate. Then type C-w to cut the region, or
221: M-w to copy the region. If you wish to cancel marking a block of text, simply
222: type C-g to cancel the operation.
223:
224: To paste the region that you've cut or copied above, simply move your cursor
225: to the desired location and then type C-y to paste it.
226:
227: Status Line
228: -----------
229:
230: At the bottom of your screen is a reverse highlighted line. This is the status
231: line and lets you know some useful information about the file you're editing.
232:
233: On the status line, you should see "Mg: tutorial". This lets you know that
234: you're editing a file named "tutorial". If you've edited this file and not
235: saved it, it should have a "**" to the left of those words. If this file is
236: read-only, you should see a "%%" to the left of those words.
237:
238: To the right of the status line, you should see L followed by digits and C
239: followed by some more digits. These indicate the line number and column number
240: of the file that your cursor is currently on. If you move the cursor around,
241: you should see the line and column number change.
242:
243: In the middle of the screen, you should see the word "(fundamental)" which
244: indicates that the current editing mode is "fundamental-mode". The mg editor
245: also supports a c-mode that is more suited to editing C code. There are also
1.6 lum 246: some other useful editing modes for different situations. See the man page
1.5 kjell 247: for mg(1) to learn about the various editing modes.
248:
249: Opening and Saving Files
250: ------------------------
251:
252: To open a file, you can use C-x C-f. You will then be prompted for a file name.
253: If you type a file name that doesn't already exist, a new file will be opened
254: for you. If the file name already exists, then it will be opened for you and
255: you can begin editing it. Note that you do not need to type the whole file
256: name for an existing file. You can type part of the file name and then press
257: the TAB key. If there is only file name that matches, mg will fill in the rest
258: of the file name for you. If there are multiple files, mg will display that
259: the choice is ambiguous. If you type the TAB key again, mg will show you all
260: the available choices for file names.
261:
262: NOTE: If you type C-x f instead of C-x C-f, you can use C-g to cancel the
263: Set-Fill-Column command. You can also use C-g to cancel the C-x C-f command
264: if you don't wish to open a new file.
265:
266: To save the file once you've edited it, use C-x C-s to save the file. When
267: mg is done saving the file, you should see the words "Wrote /path/to/file"
268: in the bottom of your screen. In general, it is a good idea to save quite
269: often. When you save a file, mg saves a backup of the file with a tilde (~)
270: character at the end.
1.1 deraadt 271:
1.5 kjell 272: Buffers
273: -------
1.1 deraadt 274:
1.5 kjell 275: The mg editor is capable of editing multiple files at the same time. When you
276: open a second file with C-x C-f, the first file is still being edited by mg.
277: You can list all the buffers that are opened by mg by typing C-x C-b. The
278: screen should divide into two and the top window will list the buffers that
279: are currently open. Use C-x o to switch to the top window (we already learned
280: this key combination above in the Windows section) and then use the arrow keys
281: to move to the buffer you wish to switch to and then type the Enter key to
282: select that buffer. Then use C-x 1 to switch back to only one window.
283:
284: You may also move back to the last opened buffer by using C-x b to toggle back
285: and forth between two buffers. Note the difference between C-x b and C-x C-b.
286:
287: >> Use C-x C-f to open a new file
288: >> Use C-x b to switch back and forth between that buffer and this one.
289:
290: To edit files in multiple windows, use C-x 2 to split the screen into two
291: windows. Then use C-x C-f to open a new file in one of the two windows. You
292: can then switch between the two windows using C-x o. You can switch between
293: buffers in any window using C-x b. To go back to one window, use C-x 1.
294:
295: To kill any buffer, use C-x k. You will be prompted for the buffer to kill.
296: By default, the current buffer is selected as the one to kill. You may also
297: type another buffer name or use C-g to cancel the operation.
1.1 deraadt 298:
1.5 kjell 299: Extended Commands
300: -----------------
1.1 deraadt 301:
1.5 kjell 302: The mg editor has several extended commands, more than what can be covered
303: by the Control and Meta keys. The mg editor gets around this by using what is
304: called the X (eXtend) command. There are two forms of this:
305:
306: C-x Character eXtension. Followed by one character.
307: M-x Named character eXtension. Followed by a long command.
308:
309: You've already seen C-x C-f and C-x C-s to open and save a file. There are
310: other longer commands. For instance, you can also open a file by typing
311: M-x open-file Enter. When you type a command using M-x, mg prompts you for
312: the command at the bottom of the screen. You can type out the whole command
313: if you wish, or you can type out part of the command and then use the TAB key
314: for autocompleting the command.
1.1 deraadt 315:
1.5 kjell 316: For instance, to replace text, you can type M-x repl TAB enter to execute
317: the replace-text command. To cancel this command, type C-g.
1.1 deraadt 318:
1.6 lum 319: To see a list of all available mg(1) commands, consult the man page.
1.1 deraadt 320:
1.5 kjell 321: Exiting mg
322: ----------
1.1 deraadt 323:
1.5 kjell 324: To exit mg temporarily and return to the shell, use C-z. This will take you
325: back to the command shell. To return back to mg, type fg in the shell and you
326: will be returned to your mg session.
1.1 deraadt 327:
1.5 kjell 328: To exit mg permanently, type C-x C-c. If you have any unsaved buffers, you
329: will be asked if you wish to save them or not.
1.1 deraadt 330:
1.5 kjell 331: Conclusion
332: ----------
1.1 deraadt 333:
1.5 kjell 334: This tutorial is meant to get new users up and running with mg. There is more
1.6 lum 335: information available via the mg(1) man page. If you have any suggestions for
1.5 kjell 336: improvement, please don't hesitate to drop a message or (better still) submit
1.6 lum 337: a diff to tech@openbsd.org.
1.1 deraadt 338:
1.5 kjell 339: History
1.1 deraadt 340: -------
341:
1.5 kjell 342: mg is a public-domain text editor. It was originally based on
343: MicroEMACS, but has since moved to more closely resemble GNU Emacs while
344: still maintaining a small memory footprint and fast speed.
345:
346: * Nov 16, 1986: First release to mod.sources
347: * Mar 3, 1987: First Release (mg1a) via comp.sources.unix
348: * May 26, 1988: Second release: (mg2a) via comp.sources.misc
349: * Jan 26, 1992: Linux port released by Charles Hedrick. This version
350: later makes its way onto tsx-11, Infomagic, and various other Linux
351: repositories.
352: * Feb 25, 2000: First import into the OpenBSD tree, where it is
353: currently maintained
354:
355: The mg editor was originally named MicroGNUEmacs. The name was changed
356: to "mg" at the request of Richard Stallman, as this software is
357: entirely unrelated to the GNU project.
1.1 deraadt 358:
1.5 kjell 359: Author Info
360: -----------
1.1 deraadt 361:
1.5 kjell 362: Original Author of this document: Mayukh Bose,
1.7 ! lum 363: Date last updated: 2011-09-10
1.1 deraadt 364:
1.5 kjell 365: Copyright
1.1 deraadt 366: ---------
367:
1.5 kjell 368: None. This document is in the public domain.
1.1 deraadt 369:
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