Annotation of 43BSDReno/contrib/jove/doc/jove.2, revision 1.1.1.1

1.1       root        1: .NH 1
                      2: Commands for English Text
                      3: .XS \n(PN
                      4: \*(SN Commands for English Text
                      5: .XE
                      6: .LP
                      7: \s-2JOVE\s0 has many commands that work on the basic units of English text:
                      8: words, sentences and paragraphs.
                      9: .NH 2
                     10: Word Commands
                     11: .XS \n(PN 5n
                     12: \*(SN Word Commands
                     13: .XE
                     14: .LP
                     15: \s-2JOVE\s0 has commands for moving over or operating on words.
                     16: By convention,
                     17: they are all ESC commands.
                     18: .IP "ESC F" 20n
                     19: Move Forward over a word.
                     20: .IP "ESC B" 20n
                     21: Move Backward over a word.
                     22: .IP "ESC D" 20n
                     23: Kill forward to the end of a word.
                     24: .IP "ESC Rubout" 20n
                     25: Kill backward to the beginning of a word.
                     26: .LP
                     27: Notice how these commands form a group that parallels the character-
                     28: based commands,
                     29: C-F,
                     30: C-B,
                     31: C-D,
                     32: and Rubout.
                     33: .LP
                     34: The commands ESC F and ESC B move forward and backward over words.
                     35: They are thus analogous to Control-F and Control-B,
                     36: which move over single characters.
                     37: Like their Control- analogues,
                     38: ESC F and ESC B move several words if given an argument.
                     39: ESC F with a negative argument moves backward like ESC B,
                     40: and ESC B with a negative argument moves forward.
                     41: Forward motion stops right after the last letter of the word,
                     42: while backward motion stops right before the first letter.
                     43: .LP
                     44: It is easy to kill a word at a time.
                     45: ESC D kills the word after point.
                     46: To be precise,
                     47: it kills everything from point to the place ESC F would move to.
                     48: Thus,
                     49: if point is in the middle of a word,
                     50: only the part after point is killed.
                     51: If some punctuation comes after point,
                     52: and before the next word,
                     53: it is killed along with the word.
                     54: If you wish to kill only the next word but not the punctuation,
                     55: simply do ESC F to get to the end,
                     56: and kill the word backwards with ESC Rubout.
                     57: ESC D takes arguments just like ESC F.
                     58: .LP
                     59: ESC Rubout kills the word before point.
                     60: It kills everything from point back to where ESC B would move to.
                     61: If point is after the space in "FOO, BAR",
                     62: then "FOO, " is killed.
                     63: If you wish to kill just "FOO",
                     64: then do a ESC B and a ESC D instead of a ESC Rubout.
                     65: .NH 2
                     66: Sentence Commands
                     67: .XS \n(PN 5n
                     68: \*(SN Sentence Commands
                     69: .XE
                     70: .LP
                     71: The \s-2JOVE\s0 commands for manipulating sentences and paragraphs are
                     72: mostly ESC commands,
                     73: so as to resemble the word-handling commands.
                     74: .IP "ESC A" 20n
                     75: Move back to the beginning of the sentence.
                     76: .IP "ESC E" 20n
                     77: Move forward to the end of the sentence.
                     78: .IP "ESC K" 20n
                     79: Kill forward to the end of the sentence.
                     80: .IP "C-X Rubout" 20n
                     81: Kill back to the beginning of the sentence.
                     82: .LP
                     83: The commands ESC A and ESC E move to the beginning and end of the
                     84: current sentence,
                     85: respectively.
                     86: They were chosen to resemble
                     87: Control-A and Control-E,
                     88: which move to the beginning and end of a line.
                     89: Unlike them,
                     90: ESC A and ESC E if repeated or given numeric arguments
                     91: move over successive sentences.
                     92: \s-2JOVE\s0 considers a sentence to end wherever there is a ".",
                     93: "?", or "!" followed by the end of a line
                     94: or by one or more spaces.
                     95: Neither ESC A nor ESC E moves past the
                     96: end of the line or spaces which delimit the sentence.
                     97: .LP
                     98: Just as C-A and C-E have a kill command,
                     99: C-K,
                    100: to go with them,
                    101: so ESC A and ESC E have a corresponding kill command ESC K which kills from
                    102: point to the end of the sentence.
                    103: With minus one as an argument it
                    104: kills back to the beginning of the sentence.
                    105: Positive arguments serve as a repeat count.
                    106: .LP
                    107: There is a special command,
                    108: C-X Rubout for killing back to the beginning of a sentence,
                    109: because this is useful when you change your
                    110: mind in the middle of composing text.
                    111: .NH 2
                    112: Paragraph Commands
                    113: .XS \n(PN 5n
                    114: \*(SN Paragraph Commands
                    115: .XE
                    116: .LP
                    117: The \s-2JOVE\s0 commands for handling paragraphs are
                    118: .IP "ESC [" 20n
                    119: Move back to previous paragraph beginning.
                    120: .IP "ESC ]" 20n
                    121: Move forward to next paragraph end.
                    122: .LP
                    123: ESC [ moves to the beginning of the current or previous paragraph, while
                    124: ESC ] moves to the end of the current or next paragraph.  Paragraphs are
                    125: delimited by lines of differing indent, or lines with text formatter
                    126: commands, or blank lines.  \s-2JOVE\s0 knows how to deal with most indented
                    127: paragraphs correctly, although it can get confused by one- or two-line
                    128: paragraphs delimited only by indentation.
                    129: .NH 2
                    130: Text Indentation Commands
                    131: .XS \n(PN 5n
                    132: \*(SN Text Indentation Commands
                    133: .XE
                    134: .LP
                    135: .IP "Tab" 20n
                    136: Indent "appropriately" in a mode-dependent fashion.
                    137: .IP "LineFeed" 20n
                    138: Is the same as Return,
                    139: except it copies the indent of the line you just left.
                    140: .IP "ESC M" 20n
                    141: Moves to the line's first non-blank character.
                    142: .LP
                    143: .LP
                    144: The way to request indentation is with the Tab command.
                    145: Its precise effect depends on the major mode.
                    146: In \fIText\fP mode,
                    147: it indents to the next tab stop.
                    148: In \fIC\fP mode,
                    149: it indents to the "right" position for C programs.
                    150: .LP
                    151: To move over the indentation on a line,
                    152: do ESC M (\fIfirst-non-blank\fP).
                    153: This command,
                    154: given anywhere on a line,
                    155: positions the cursor at the first non-blank, non-tab character on the line.
                    156: .NH 2
                    157: Text Filling
                    158: .XS \n(PN 5n
                    159: \*(SN Text Filling
                    160: .XE
                    161: .LP
                    162: \fIAuto Fill\fP mode causes text to be \fIfilled\fP
                    163: (broken up into lines that fit in a specified width)
                    164: automatically as you type it in.
                    165: If you alter existing text so that it is no longer properly filled,
                    166: \s-2JOVE\s0 can fill it again if you ask.
                    167: .LP
                    168: Entering \fIAuto Fill\fP mode is done with ESC X \fIauto-fill-mode\fP.
                    169: From then on,
                    170: lines are broken automatically at spaces when they get longer than the
                    171: desired width.
                    172: To leave \fIAuto Fill\fP mode,
                    173: once again execute ESC X \fIauto-fill-mode\fP.
                    174: When \fIAuto Fill\fP mode is in effect,
                    175: the word \fBFill\fP appears in the mode line.
                    176: .LP
                    177: If you edit the middle of a paragraph,
                    178: it may no longer correctly be filled.
                    179: To refill a paragraph,
                    180: use the command ESC J (\fIfill-paragraph\fP).
                    181: It causes the paragraph that point is inside to be filled.
                    182: All the line breaks are removed and new ones inserted where necessary.
                    183: .LP
                    184: The maximum line width for filling is in the variable \fIright-margin\fP.
                    185: Both ESC J and auto-fill make sure that no line exceeds this width.
                    186: The value of \fIright-margin\fP is initially 78.
                    187: .LP
                    188: Normally ESC J figures out the indent of the paragraph and uses that same
                    189: indent when filling.  If you want to change the indent of a paragraph you
                    190: set \fIleft-margin\fP to the new position and type C-U\ ESC\ J.
                    191: \fIfill-paragraph\fP, when supplied a numeric argument, uses the value of
                    192: \fIleft-margin\fP.
                    193: .LP
                    194: If you know where you want to set the right margin but you don't know the
                    195: actual value, move to where you want to set the value and use the
                    196: \fIright-margin-here\fP command.  \fIleft-margin-here\fP does the same
                    197: for the \fIleft-margin\fP variable.
                    198: .NH 2
                    199: Case Conversion Commands
                    200: .XS \n(PN 5n
                    201: \*(SN Case Conversion Commands
                    202: .XE
                    203: .LP
                    204: .IP "ESC L" 15n
                    205: Convert following word to lower case.
                    206: .IP "ESC U" 15n
                    207: Convert following word to upper case.
                    208: .IP "ESC C" 15n
                    209: Capitalize the following word.
                    210: .LP
                    211: .LP
                    212: The word conversion commands are most useful.
                    213: ESC L converts the word after point to lower case,
                    214: moving past it.
                    215: Thus,
                    216: successive ESC L's convert successive words.
                    217: ESC U converts to all capitals instead,
                    218: while ESC C puts the first letter of the word into upper case and the
                    219: rest into lower case.
                    220: All these commands convert several words at once if given an argument.
                    221: They are especially convenient for
                    222: converting a large amount of text from all upper case to mixed case,
                    223: because you can move through the test using ESC L,
                    224: ESC U or ESC C on each word as appropriate.
                    225: .LP
                    226: When given a negative argument,
                    227: the word case conversion commands apply to
                    228: the appropriate number of words before point,
                    229: but do not move point.
                    230: This is convenient when you have just typed a word in the wrong case.
                    231: You can give the case conversion command and continue typing.
                    232: .LP
                    233: If a word case conversion command is given in the middle of a word,
                    234: it applies only to the part of the word which follows the cursor,
                    235: treating it as a whole word.
                    236: .LP
                    237: The other case conversion functions are \fIcase-region-upper\fP and
                    238: \fIcase-region-lower\fP,
                    239: which convert everything between point and mark to the specified case.
                    240: Point and mark remain unchanged.
                    241: .NH 2
                    242: Commands for Fixing Typos
                    243: .XS \n(PN 5n
                    244: \*(SN Commands for Fixing Typos
                    245: .XE
                    246: .LP
                    247: In this section we describe the commands that are especially useful
                    248: for the times when you catch a mistake on your text after you have made it,
                    249: or change your mind while composing text on line.
                    250: .IP "Rubout" 25n
                    251: Delete last character.
                    252: .IP "ESC Rubout" 25n
                    253: Kill last word.
                    254: .IP "C-X Rubout" 25n
                    255: Kill to beginning of sentence.
                    256: .IP "C-T" 25n
                    257: Transpose two characters.
                    258: .IP "C-X C-T" 25n
                    259: Transpose two lines.
                    260: .IP "ESC Minus ESC L" 25n
                    261: Convert last word to lower case.
                    262: .IP "ESC Minus ESC U" 25n
                    263: Convert last word to upper case.
                    264: .IP "ESC Minus ESC C" 25n
                    265: Convert last word to lower case with capital initial.
                    266: .LP
                    267: .NH 2
                    268: Killing Your Mistakes
                    269: .XS \n(PN 5n
                    270: \*(SN Killing Your Mistakes
                    271: .XE
                    272: .LP
                    273: The Rubout command is the most important correction command.
                    274: When used among printing (self-inserting) characters,
                    275: it can be thought of as canceling the last character typed.
                    276: .LP
                    277: When your mistake is longer than a couple of characters,
                    278: it might be more convenient to use ESC Rubout or C-X Rubout.
                    279: ESC Rubout kills back to the start of the last word,
                    280: and C-X Rubout kills back to the start of the last sentence.
                    281: C-X Rubout is particularly useful when
                    282: you are thinking of what to write as you type it,
                    283: in case you change your mind about phrasing.
                    284: ESC Rubout and C-X Rubout save the killed text for C-Y and ESC Y to retrieve.
                    285: .LP
                    286: ESC Rubout is often useful even when you have typed only a few
                    287: characters wrong,
                    288: if you know you are confused in your typing and aren't sure what you typed.
                    289: At such a time,
                    290: you cannot correct with
                    291: Rubout except by looking at the screen to see what you did.
                    292: It requires less thought to kill the whole word and start over again,
                    293: especially if the system is heavily loaded.
                    294: .LP
                    295: If you were typing a command or command parameters, C-G will abort the
                    296: command with no further processing.
                    297: .NH 2
                    298: Transposition
                    299: .XS \n(PN 5n
                    300: \*(SN Transposition
                    301: .XE
                    302: .LP
                    303: The common error of transposing two characters can be fixed
                    304: with the C-T (\fItranspose-characters\fP) command.
                    305: Normally,
                    306: C-T transposes the two characters on either side of the cursor
                    307: and moves the cursor forward one character.  Repeating the command
                    308: several times "drags" a character to the right.
                    309: (Remember that \fIpoint\fP is considered to be between two characters,
                    310: even though the visible cursor in your terminal is on only one of them.)
                    311: When given at the end of a line,
                    312: rather than switching the last character of the line with the line separator,
                    313: which would be useless,
                    314: C-T transposes the last two characters on the line.
                    315: So,
                    316: if you catch your transposition error right away,
                    317: you can fix it with just a C-T.
                    318: If you don't catch it so fast,
                    319: you must move the cursor back to between the two characters.
                    320: .LP
                    321: To transpose two lines,
                    322: use the C-X C-T (\fItranspose-lines\fP) command.  The line containing the
                    323: cursor is exchanged with the line above it; the cursor is left at the
                    324: beginning of the line following its original position.
                    325: .NH 2
                    326: Checking and Correcting Spelling
                    327: .XS \n(PN 5n
                    328: \*(SN Checking and Correcting Spelling
                    329: .XE
                    330: .LP
                    331: When you write a paper,
                    332: you should correct its spelling at some point close to finishing it.
                    333: To correct the entire buffer,
                    334: do ESC X \fIspell-buffer\fP.
                    335: This invokes the
                    336: .UX
                    337: .I spell
                    338: program,
                    339: which prints a list of all the misspelled words.
                    340: \s-2JOVE\s0 catches the list and places it in a
                    341: \s-2JOVE\s0 buffer called \fBSpell\fP.
                    342: You are given an opportunity to delete from that buffer any words that
                    343: aren't really errors;
                    344: then \s-2JOVE\s0 looks up each misspelled word and
                    345: remembers where it is in the buffer being corrected.
                    346: Then you can go forward to each misspelled word with C-X C-N (\fInext-error\fP)
                    347: and backward with C-X C-P (\fIprevious-error\fP).
                    348: See the section entitled \fIError Message Parsing\fP.
                    349: .NH 1
                    350: File Handling
                    351: .XS \n(PN
                    352: \*(SN File Handling
                    353: .XE
                    354: .LP
                    355: The basic unit of stored data is the file.
                    356: Each program,
                    357: each paper,
                    358: lives usually in its own file.
                    359: To edit a program or paper,
                    360: the editor must be told the name of the file that contains it.
                    361: This is called \fIvisiting\fP a file.
                    362: To make your changes to the file permanent on disk,
                    363: you must \fIsave\fP the file.
                    364: .NH 2
                    365: Visiting Files
                    366: .XS \n(PN 5n
                    367: \*(SN Visiting Files
                    368: .XE
                    369: .LP
                    370: .IP "C-X C-V" 15n
                    371: Visit a file.
                    372: .IP "C-X C-R" 15n
                    373: Same as C-X C-V.
                    374: .IP "C-X C-S" 15n
                    375: Save the visited file.
                    376: .IP "ESC ~" 15n
                    377: Tell \s-2JOVE\s0 to forget that the buffer has been changed.
                    378: .LP
                    379: .LP
                    380: \fIVisiting\fP a file means copying its contents into \s-2JOVE\s0 where you
                    381: can edit them.
                    382: \s-2JOVE\s0 remembers the name of the file you visited.
                    383: Unless you use the multiple buffer feature of \s-2JOVE\s0,
                    384: you can only be visiting one file at a time.
                    385: The name of the current selected buffer is visible in the mode line.
                    386: .LP
                    387: The changes you make with \s-2JOVE\s0 are made in a copy inside \s-2JOVE\s0.
                    388: The file itself is not changed.
                    389: The changed text is not permanent until you \fIsave\fP it in a file.
                    390: The first time you change the text,
                    391: an asterisk appears at the end of the mode line; this indicates that the text
                    392: contains fresh changes which will be lost unless you save them.
                    393: .LP
                    394: To visit a file,
                    395: use the command C-X C-V.
                    396: Follow the command with the name of the file you wish to visit,
                    397: terminated by a Return.
                    398: You can abort the command by typing C-G,
                    399: or edit the filename with many of the standard \s-2JOVE\s0 commands
                    400: (e.g., C-A, C-E, C-F, ESC F, ESC Rubout).
                    401: If the filename you wish to visit is similar to the filename in the
                    402: mode line (the default filename),
                    403: you can type C-R to insert the default and then edit it.
                    404: If you do type a Return to finish the command,
                    405: the new file's text appears on the screen,
                    406: and its name appears in the mode line.
                    407: In addition,
                    408: its name becomes the new default filename.
                    409: .LP
                    410: If you wish to save the file and make your changes permanent,
                    411: type C-X C-S.
                    412: After the save is finished,
                    413: C-X C-S prints the filename and the
                    414: number of characters and lines that it wrote to the file.
                    415: If there are no changes to save (no asterisk at the end of the mode line),
                    416: the file is not saved;
                    417: otherwise the changes saved and the asterisk at the end of
                    418: the mode line will disappear.
                    419: .LP
                    420: What if you want to create a file?  Just visit it.
                    421: \s-2JOVE\s0 prints
                    422: \fI(New file)\fP but aside from that behaves as if you had visited an existing
                    423: empty file.
                    424: If you make any changes and save them,
                    425: the file is created.
                    426: If you visit a nonexistent file unintentionally
                    427: (because you typed the wrong filename),
                    428: go ahead and visit the file you meant.
                    429: If you don't save the unwanted file,
                    430: it is not created.
                    431: .LP
                    432: If you alter one file and then visit another in the same buffer,
                    433: \s-2JOVE\s0 offers to save the old one.
                    434: If you answer YES,
                    435: the old file is saved;
                    436: if you answer NO,
                    437: all the changes you have made to it since the last save are lost.
                    438: You should not type ahead after a file visiting
                    439: command,
                    440: because your type-ahead might answer an unexpected question
                    441: in a way that you would regret.
                    442: .LP
                    443: Sometimes you will change a buffer by accident.
                    444: Even if you undo the effect of the change by editing,
                    445: \s-2JOVE\s0 still knows that "the buffer has been changed".
                    446: You can tell \s-2JOVE\s0 to pretend that there have been no changes with the
                    447: ESC \s+2~\s0 command (\fImake-buffer-unmodified\fP).
                    448: This command simply clears the "modified" flag which
                    449: says that the buffer contains changes which need to be saved.
                    450: Even if
                    451: the buffer really \fIis\fP changed \s-2JOVE\s0 will still act as if it were not.
                    452: .LP
                    453: If \s-2JOVE\s0 is about to save a file and sees that the date of the version
                    454: on disk does not match what \s-2JOVE\s0 last read or wrote,
                    455: \s-2JOVE\s0 notifies you of this fact,
                    456: and asks what to do, because this probably means that something is wrong.
                    457: For example,
                    458: somebody else may have been editing the same file.
                    459: If this is so,
                    460: there is a good chance that your work
                    461: or his work will be lost if you don't take the proper steps.
                    462: You should first find out exactly what is going on.
                    463: If you determine that somebody else has modified the file,
                    464: save your file under a different filename and then DIFF the two files
                    465: to merge the two sets of changes.  (The "patch" command is useful for
                    466: applying the results of context diffs directly).
                    467: Also get in touch with the other person so that the files don't diverge
                    468: any further.
                    469: .NH 2
                    470: How to Undo Drastic Changes to a File
                    471: .XS \n(PN 5n
                    472: \*(SN How to Undo Drastic Changes to a File
                    473: .XE
                    474: .LP
                    475: If you have made several extensive changes to a file and then change
                    476: your mind about them,
                    477: and you haven't yet saved them,
                    478: you can get rid of them by reading in the previous version of the file.
                    479: You can do this with the C-X C-V command,
                    480: to visit the unsaved version of the file.
                    481: .NH 2
                    482: Recovering from system/editor crashes
                    483: .XS \n(PN 5n
                    484: \*(SN Recovering from system/editor crashes
                    485: .XE
                    486: .LP
                    487: JOVE does not have \fIAuto Save\fP mode, but it does provide a way to
                    488: recover your work in the event of a system or editor crash.  JOVE saves
                    489: information about the files you're editing every so many changes to a
                    490: buffer to make recovery possible.  Since a relatively small amount of
                    491: information is involved it's hardly even noticeable when JOVE does this.  The
                    492: variable "sync-frequency" says how often to save the necessary
                    493: information, and the default is every 50 changes.  50 is a very
                    494: reasonable number: if you are writing a paper you will not lose more than
                    495: the last 50 characters you typed, which is less than the average length
                    496: of a line.
                    497: .NH 2
                    498: Miscellaneous File Operations
                    499: .XS \n(PN 5n
                    500: \*(SN Miscellaneous File Operations
                    501: .XE
                    502: .LP
                    503: .LP
                    504: ESC X \fIwrite-file\fP <file><return> writes the contents of the buffer
                    505: into the file <file>,
                    506: and then visits that file.
                    507: It can be thought of as a way of "changing the name" of
                    508: the file you are visiting.
                    509: Unlike C-X C-S,
                    510: \fIwrite-file\fP saves even if the buffer has not been changed.
                    511: C-X C-W is another way of getting this command.
                    512: .LP
                    513: ESC X \fIinsert-file\fP <file><return> inserts the contents of <file> into the
                    514: buffer at point,
                    515: leaving point unchanged before the contents.
                    516: You can also use C-X C-I to get this command.
                    517: .LP
                    518: ESC X \fIwrite-region\fP <file><return> writes the region (the text between
                    519: point and mark) to the specified file.
                    520: It does not set the visited filename.
                    521: The buffer is not changed.
                    522: .LP
                    523: ESC X \fIappend-region\fP <file><return> appends the region to <file>.
                    524: The text is added to the end of <file>.
                    525: .NH 1
                    526: Using Multiple Buffers
                    527: .XS \n(PN
                    528: \*(SN Using Multiple Buffers
                    529: .XE
                    530: .LP
                    531: When we speak of "the buffer",
                    532: which contains the text you are editing,
                    533: we have given the impression that there is only one.
                    534: In fact,
                    535: there may be many of them,
                    536: each with its own body of text.
                    537: At any time only one buffer can be \fIselected\fP and available for editing,
                    538: but it isn't hard to switch to a different one.
                    539: Each buffer individually remembers which file it is visiting,
                    540: what modes are in effect,
                    541: and whether there are any changes that need saving.
                    542: .IP "C-X B" 15n
                    543: Select or create a buffer.
                    544: .IP "C-X C-F" 15n
                    545: Visit a file in its own buffer.
                    546: .IP "C-X C-B" 15n
                    547: List the existing buffers.
                    548: .IP "C-X K" 15n
                    549: Kill a buffer.
                    550: .LP
                    551: Each buffer in \s-2JOVE\s0 has a single name,
                    552: which normally doesn't change.
                    553: A buffer's name can be any length.
                    554: The name of the currently selected buffer
                    555: and the name of the file visited in it
                    556: are visible in the mode line when you are at top level.
                    557: A newly started \s-2JOVE\s0 has only one buffer,
                    558: named \fBMain\fP, unless you specified files to edit in the
                    559: shell command that started \s-2JOVE\s0.
                    560: .NH 2
                    561: Creating and Selecting Buffers
                    562: .XS \n(PN 5n
                    563: \*(SN Creating and Selecting Buffers
                    564: .XE
                    565: .LP
                    566: To create a new buffer,
                    567: you need only think of a name for it (say, FOO)
                    568: and then do C-X B FOO<return>,
                    569: which is the command C-X B (\fIselect-buffer\fP) followed by the name.
                    570: This makes a new,
                    571: empty buffer (if one by that name didn't previously exist) 
                    572: and selects it for editing.
                    573: The new buffer is not visiting any file,
                    574: so if you try to save it you will be asked for the filename to use.
                    575: Each buffer has its own major mode;
                    576: the new buffer's major mode is \fIText\fP mode by default.
                    577: .LP
                    578: To return to buffer FOO later after having switched to another,
                    579: the same command C-X B FOO<return> is used,
                    580: since C-X B can tell whether a buffer named FOO exists already or not.
                    581: C-X B Main<return> reselects the buffer Main that \s-2JOVE\s0 started out with.
                    582: Just C-X B<return> reselects the previous buffer.
                    583: Repeated C-X B<return>'s alternate between the last two buffers selected.
                    584: .LP
                    585: You can also read a file into its own newly created buffer,
                    586: all with one command: C-X C-F (\fIfind-file\fP),
                    587: followed by the filename.
                    588: The name of the buffer is the last element of the file's pathname.
                    589: C-F stands for "Find",
                    590: because if the specified file already resides in a buffer in your \s-2JOVE\s0,
                    591: that buffer is reselected.
                    592: So you need not remember whether you have brought the file in already or not.
                    593: A buffer created by C-X C-F can be reselected later with C-X B or C-X C-F,
                    594: whichever you find more convenient.
                    595: Nonexistent files can be created with C-X C-F just as they can with C-X C-V.
                    596: .NH 2
                    597: Using Existing Buffers
                    598: .XS \n(PN 5n
                    599: \*(SN Using Existing Buffers
                    600: .XE
                    601: .LP
                    602: To get a list of all the buffers that exist,
                    603: do C-X C-B (\fIlist-buffers\fP).
                    604: Each buffer's type,
                    605: name,
                    606: and visited filename is printed.
                    607: An asterisk before the buffer name indicates a
                    608: buffer which contains changes that have not been saved. The number
                    609: that appears at the beginning of a line in a C-X C-B listing is that
                    610: buffer's \fIbuffer number\fP.
                    611: You can select a buffer by typing its number in place of its name.
                    612: If a buffer with that number doesn't already exist,
                    613: a new buffer is created with that number as its name.
                    614: .LP
                    615: If several buffers have modified text in them,
                    616: you should save some of them with C-X C-M (\fIwrite-modified-files\fP).
                    617: This finds all the buffers that need saving and then saves them.
                    618: Saving the buffers this way is much
                    619: easier and more efficient (but more dangerous)
                    620: than selecting each one and typing C-X C-S.
                    621: If you give C-X C-M an argument, \s-2JOVE\s0 will ask for confirmation
                    622: before saving each buffer.
                    623: .LP
                    624: ESC X \fIrename-buffer\fP <new name><return> changes the name of the currently
                    625: selected buffer.
                    626: .LP
                    627: ESC X \fIerase-buffer\fP <buffer name><return> erases the contents of the
                    628: <buffer name> without deleting the buffer entirely.
                    629: .NH 2
                    630: Killing Buffers
                    631: .XS \n(PN 5n
                    632: \*(SN Killing Buffers
                    633: .XE
                    634: .LP
                    635: After you use a \s-2JOVE\s0 for a while,
                    636: it may fill up with buffers which you no longer need.
                    637: Eventually you can reach a point where trying to
                    638: create any more results in an "out of memory" or "out of lines"
                    639: error.
                    640: When this happens you will want to kill some buffers with the
                    641: C-X K (\fIdelete-buffer\fP) command.
                    642: You can kill the buffer FOO by doing C-X K FOO<return>.
                    643: If you type C-X K <return> JOVE will kill the previously selected buffer.
                    644: If you try to kill a buffer that needs saving \s-2JOVE\s0
                    645: will ask you to confirm it.
                    646: .LP
                    647: If you need to kill several buffers, use the command \fIkill-some-buffers\fP.
                    648: This prompts you with the name of each buffer and asks for confirmation
                    649: before killing that buffer.
                    650: .NH 1
                    651: Controlling the Display
                    652: .XS \n(PN
                    653: \*(SN Controlling the Display
                    654: .XE
                    655: .LP
                    656: Since only part of a large file will fit on the screen,
                    657: \s-2JOVE\s0 tries to show the part that is likely to be interesting.
                    658: The display control commands allow you to see a different part of the file.
                    659: .IP "C-L" 15n
                    660: Reposition point at a specified vertical position,
                    661: OR clear and redraw the screen with point in the same place.
                    662: .IP "C-V" 15n
                    663: Scroll forwards (a screen or a few lines).
                    664: .IP "ESC V" 15n
                    665: Scroll backwards.
                    666: .IP "C-Z" 15n
                    667: Scroll forward some lines.
                    668: .IP "ESC Z" 15n
                    669: Scroll backwards some lines.
                    670: .LP
                    671: .LP
                    672: The terminal screen is rarely large enough to display all of your
                    673: file.
                    674: If the whole buffer doesn't fit on the screen,
                    675: \s-2JOVE\s0 shows a contiguous portion of it,
                    676: containing 
                    677: .I point.
                    678: It continues to show approximately the same portion
                    679: until point moves outside of what is displayed;
                    680: then \s-2JOVE\s0 chooses a new portion centered around the new 
                    681: .I point.
                    682: This is \s-2JOVE\s0's guess as to what you are most interested in seeing,
                    683: but if the guess is wrong,
                    684: you can use the display control commands to see a different portion.
                    685: The available screen area through which you can see part of
                    686: the buffer is called \fIthe window\fP,
                    687: and the choice of where in the
                    688: buffer to start displaying is also called \fIthe window\fP.  (When 
                    689: there is only one window, it plus the mode line and the input line take
                    690: up the whole screen).
                    691: .LP
                    692: First we describe how \s-2JOVE\s0 chooses a new window position on its own.
                    693: The goal is usually to place 
                    694: .I point 
                    695: half way down the window.
                    696: This is controlled by the variable \fIscroll-step\fP,
                    697: whose value is the number of
                    698: lines above the bottom or below the top of the window that the line
                    699: containing point is placed.
                    700: A value of 0 (the initial value) means center 
                    701: .I point
                    702: in the window.
                    703: .LP
                    704: The basic display control command is C-L (\fIredraw-display\fP).
                    705: In its simplest form,
                    706: with no argument,
                    707: it tells \s-2JOVE\s0 to choose a new window position,
                    708: centering point half way from the top as usual.
                    709: .LP
                    710: C-L with a positive argument chooses a new window so as to put point
                    711: that many lines from the top.
                    712: An argument of zero puts point on the very top line.
                    713: Point does not move with respect to the text; rather,
                    714: the text and point move rigidly on the screen.
                    715: .LP
                    716: If point stays on the same line,
                    717: the window is first cleared and then redrawn.
                    718: Thus,
                    719: two C-L's in a row are guaranteed to clear the current window.
                    720: ESC C-L will clear and redraw the entire screen.
                    721: .LP
                    722: The \fIscrolling\fP commands C-V,
                    723: ESC V,
                    724: C-Z,
                    725: and ESC Z,
                    726: let you move the whole display up or down a few lines.
                    727: C-V (\fInext-page\fP) with an
                    728: argument shows you that many more lines at the bottom of the screen,
                    729: moving the text and point up together as C-L might.
                    730: C-V with a
                    731: negative argument shows you more lines at the top of the screen,
                    732: as does ESC V (\fIprevious-page\fP) with a positive argument.
                    733: .LP
                    734: To read the buffer a window at a time,
                    735: use the C-V command with no argument.
                    736: It takes the last line at the bottom of the window and puts
                    737: it at the top,
                    738: followed by nearly a whole window of lines not visible before.
                    739: Point is put at the top of the window.
                    740: Thus, each C-V shows the "next page of text",
                    741: except for one line of overlap to provide context.
                    742: To move backward,
                    743: use ESC V without an argument,
                    744: which moves a whole window backwards (again with a line of overlap).
                    745: .LP
                    746: C-Z and ESC Z scroll one line forward and one line backward,
                    747: respectively.
                    748: These are convenient for moving in units of lines
                    749: without having to type a numeric argument.
                    750: .NH 2
                    751: Multiple Windows
                    752: .XS \n(PN 5n
                    753: \*(SN Multiple Windows
                    754: .XE
                    755: .LP
                    756: \s-2JOVE\s0 allows you to split the screen into two or more \fIwindows\fP and
                    757: use them to display parts of different files,
                    758: or different parts of the same file.
                    759: .IP "C-X 2" 15n
                    760: Divide the current window into two smaller ones.
                    761: .IP "C-X 1" 15n
                    762: Delete all windows but the current one.
                    763: .IP "C-X D" 15n
                    764: Delete current window.
                    765: .IP "C-X N" 15n
                    766: Switch to the next window.
                    767: .IP "C-X P" 15n
                    768: Switch to the previous window.
                    769: .IP "C-X O" 15n
                    770: Same as C-X P.
                    771: .IP "C-X ^" 15n
                    772: Make this window bigger.
                    773: .IP "ESC C-V" 15n
                    774: Scroll the other window.
                    775: .LP
                    776: .LP
                    777: When using \fImultiple window\fP mode,
                    778: the text portion of the screen
                    779: is divided into separate parts called \fIwindows\fP,
                    780: which can display different pieces of text.
                    781: Each window can display different files,
                    782: or parts of the same file.
                    783: Only one of the windows is 
                    784: .I active; 
                    785: that is
                    786: the window which the cursor is in.
                    787: Editing normally takes place in that window alone.
                    788: To edit in another window,
                    789: you would give a command to move the cursor to the other window,
                    790: and then edit there.
                    791: .LP
                    792: Each window displays a mode line for the buffer it's displaying.
                    793: This is useful to keep track of which window corresponds with which
                    794: file.  In addition, the mode line serves as a separator between windows.
                    795: By setting the variable \fImode-line-should-standout\fP to "on" you can
                    796: have \s-2JOVE\s0 display the mode-line in reverse video (assuming your
                    797: particular terminal has the reverse video capability).
                    798: .LP
                    799: The command C-X 2 (\fIsplit-current-window\fP) enters multiple window mode.
                    800: A new mode line appears across the middle of the screen,
                    801: dividing the text display area into two halves.
                    802: Both windows contain the same buffer and display the same position in it,
                    803: namely where point was at the time you issued the command.
                    804: The cursor moves to the second window.
                    805: .LP
                    806: To return to viewing only one window,
                    807: use the command C-X 1 (\fIdelete-other-windows\fP).
                    808: The current window expands to fill the whole screen,
                    809: and the other windows disappear until the next C-X 2.
                    810: (The buffers and their contents are unaffected by any of the
                    811: window operations).
                    812: .LP
                    813: While there is more than one window,
                    814: you can use C-X N (\fInext-window\fP) to switch to the next window,
                    815: and C-X P (\fIprevious-window\fP) to switch to the previous one.
                    816: If you are in the bottom window and you type C-X N,
                    817: you will be placed in the top window,
                    818: and the same kind of thing happens when you type C-X P in the top window,
                    819: namely you will be placed in the bottom window.
                    820: C-X O is the same as C-X P.
                    821: It stands for "other window" because when there are only two windows,
                    822: repeated use of this command will switch between the two windows.
                    823: .LP
                    824: Often you will be editing one window while using the other just for reference.
                    825: Then,
                    826: the command ESC C-V (\fIpage-next-window\fP) is very useful.
                    827: It scrolls the next window,
                    828: as if you switched to the next window,
                    829: typed C-V,
                    830: and switched back,
                    831: without your having to do all that.
                    832: With a negative argument,
                    833: ESC C-V will do an ESC V in the next window.
                    834: .LP
                    835: When a window splits,
                    836: both halves are approximately the same size.
                    837: You can redistribute the screen space between the windows with
                    838: the C-X ^ (\fIgrow-window\fP) command.
                    839: It makes the currently selected window grow one line bigger,
                    840: or as many lines as is specified with a numeric argument.
                    841: Use ESC X \fIshrink-window\fP to make the current window smaller.
                    842: .NH 2
                    843: Multiple Windows and Multiple Buffers
                    844: .XS \n(PN 5n
                    845: \*(SN Multiple Windows and Multiple Buffers
                    846: .XE
                    847: .LP
                    848: Buffers can be selected independently in each window.
                    849: The C-X B command selects a new buffer in whichever window contains
                    850: the cursor.
                    851: Other windows' buffers do not change.
                    852: .LP
                    853: You can view the same buffer in more than one window.
                    854: Although the same buffer appears in both windows,
                    855: they have different values of point,
                    856: so you can move around in one window while the other window
                    857: continues to show the same text.
                    858: Then,
                    859: having found one place you wish to refer to, you can go back into the
                    860: other window with C-X O or C-X P to make your changes.
                    861: .LP
                    862: If you have the same buffer in both windows,
                    863: you must beware of trying to visit a different file in one of
                    864: the windows with C-X C-V,
                    865: because if you bring a new file into this buffer,
                    866: it will replaced the old file in \fIboth\fP windows.
                    867: To view different files in different windows,
                    868: you must switch buffers in one of the windows first
                    869: (with C-X B or C-X C-F, perhaps).
                    870: .LP
                    871: A convenient "combination" command for viewing something in another
                    872: window is C-X 4 (\fIwindow-find\fP).
                    873: With this command you can ask to see any specified buffer,
                    874: file or tag in the other window.
                    875: Follow the C-X 4 with either B and a buffer name,
                    876: F and a filename,
                    877: or T and a tag name.
                    878: This switches to the other window and finds there what you specified.
                    879: If you were previously in one-window mode,
                    880: multiple-window mode is entered.
                    881: C-X 4 B is similar to C-X 2 C-X B.
                    882: C-X 4 F is similar to C-X 2 C-X C-F.
                    883: C-X 4 T is similar to C-X 2 C-X
                    884: T.
                    885: The difference is one of efficiency,
                    886: and also that C-X 4 works equally well if you are already using two windows.
                    887: .NH 1
                    888: Processes Under \s-2JOVE\s0
                    889: .XS \n(PN
                    890: \*(SN Processes Under \s-2JOVE\s0
                    891: .XE
                    892: .LP
                    893: Another feature in \s-2JOVE\s0 is its ability to interact with
                    894: .UX
                    895: in a useful way.
                    896: You can run other
                    897: .UX
                    898: commands from \s-2JOVE\s0 and catch their output in \s-2JOVE\s0 buffers.
                    899: In this chapter we will discuss the different
                    900: ways to run and interact with
                    901: .UX
                    902: commands.
                    903: .NH 2
                    904: Non-interactive
                    905: .UX
                    906: commands
                    907: .XS \n(PN 5n
                    908: \*(SN Non-interactive
                    909: .XE
                    910: .LP
                    911: To run a
                    912: .UX
                    913: command from \s-2JOVE\s0 just type "C-X !" followed by the name
                    914: of the command terminated with Return.
                    915: For example,
                    916: to get a list of all the users on the system,
                    917: you do:
                    918: .DS I
                    919: C-X ! who<return>
                    920: .DE
                    921: Then \s-2JOVE\s0 picks a reasonable buffer in which the output from the
                    922: command will be placed.
                    923: E.g.,
                    924: "who" uses a buffer called \fBwho\fP;
                    925: "ps alx" uses \fBps\fP;
                    926: and "fgrep -n foo *.c" uses \fBfgrep\fP.
                    927: If \s-2JOVE\s0
                    928: wants to use a buffer that already exists it first erases the old contents.
                    929: If the buffer it selects holds a file,
                    930: not output from a previous shell command,
                    931: you must first delete that buffer with C-X K.
                    932: .LP
                    933: Once \s-2JOVE\s0 has picked a buffer it puts that buffer in a window so you
                    934: can see the command's output as it is running.
                    935: If there is only one window \s-2JOVE\s0 will automatically make another one.
                    936: Otherwise,
                    937: \s-2JOVE\s0
                    938: tries to pick the most convenient window which isn't the current one.
                    939: .LP
                    940: It's not a good idea to type anything while the command is running.
                    941: There are two reasons for this:
                    942: .IP (i)
                    943: \s-2JOVE\s0 won't see the characters (thus won't execute them) until the
                    944: command finishes,
                    945: so you may forget what you've typed.
                    946: .IP (ii)
                    947: Although \s-2JOVE\s0 won't know what you've typed,
                    948: it 
                    949: .I will
                    950: know that you've typed something,
                    951: and then it will try to be "smart" and not update the
                    952: display until it's interpreted what you've typed.
                    953: But,
                    954: of course,
                    955: \s-2JOVE\s0 won't interpret what you type until the
                    956: .UX
                    957: command completes,
                    958: so you're left with the uneasy feeling you get when you
                    959: don't know what the hell the computer is doing*.
                    960: .FS
                    961: *This is a bug and should be fixed,
                    962: but probably won't be for a while.
                    963: .FE
                    964: .LP
                    965: If you want to interrupt the command for some reason (perhaps you
                    966: mistyped it, or you changed your mind) you can type C-].
                    967: Typing this
                    968: inside \s-2JOVE\s0 while a process is running is the same as typing C-C when
                    969: you are outside \s-2JOVE\s0,
                    970: namely the process stops in a hurry.
                    971: .LP
                    972: When the command finishes, \s-2JOVE\s0 puts you back in the window in which 
                    973: you started.
                    974: Then it prints a message indicating whether or not the command
                    975: completed successfully in its (the command's) opinion.
                    976: That is,
                    977: if the command had what it considers an error
                    978: (or you interrupt it with C-])
                    979: \s-2JOVE\s0 will print an appropriate message.
                    980: 
                    981: .NH 2
                    982: Limitations of Non-Interactive Processes
                    983: .XS \n(PN 5n
                    984: \*(SN Limitations of Non-Interactive Processes
                    985: .XE
                    986: .LP
                    987: The reason these are called non-interactive processes is that you
                    988: can't type any input to them; you can't interact with them; they can't
                    989: ask you questions because there is no way for you to answer.
                    990: For example,
                    991: you can't run a command interpreter (a shell), or 
                    992: .I mail
                    993: or 
                    994: .I crypt
                    995: with C-X ! because there is no way to provide it with input.
                    996: Remember that \s-2JOVE\s0 (not the process in the window)
                    997: is listening to your keyboard,
                    998: and \s-2JOVE\s0 waits until the process dies before it looks at
                    999: what you type.
                   1000: .LP
                   1001: C-X ! is useful for running commands that do some output and then exit.
                   1002: For example,
                   1003: it's very useful to use with the C compiler to
                   1004: catch compilation error messages (see Compiling C Programs),
                   1005: or with the \fIgrep\fP commands.
                   1006: .NH 2
                   1007: Interactive Processes \(em Run a Shell in a Window
                   1008: .XS \n(PN 5n
                   1009: \*(SN Interactive Processes \(em Run a Shell in a Window
                   1010: .XE
                   1011: .LP
                   1012: Some versions of \s-2JOVE\s0\(dg
                   1013: .FS
                   1014: \(dg For example, the version provided with 4.3BSD.
                   1015: .FE
                   1016: have the capability of running interactive
                   1017: processes.
                   1018: This is more useful than non-interactive processes for
                   1019: certain types of jobs:
                   1020: .IP (i)
                   1021: You can go off and do some editing while the command is running.
                   1022: This is useful for commands that do sporadic output and run for fairly long
                   1023: periods of time.
                   1024: .IP (ii)
                   1025: Unlike non-interactive processes,
                   1026: you can type input to these.
                   1027: In addition,
                   1028: you can edit what you type with the power of all the \s-2JOVE\s0
                   1029: commands \fIbefore\fP you send the input to the process.
                   1030: This is a really important feature,
                   1031: and is especially useful for running a shell in a window.
                   1032: .IP (iii)
                   1033: Because you can continue with normal editing while one of the
                   1034: processes is running,
                   1035: you can create a bunch of contexts and manage them
                   1036: (select them, delete them, or temporarily put them aside)
                   1037: with \s-2JOVE\s0's window and buffer mechanisms.
                   1038: .LP
                   1039: Although we may have given an image of processes being attached to 
                   1040: .I windows,
                   1041: in fact they are attached to 
                   1042: .I buffers.
                   1043: Therefore,
                   1044: once an \fIi-process\fP is running you can select another buffer into that window,
                   1045: or if you wish you can delete the window altogether.
                   1046: If you reselect that buffer later it will be up to date.
                   1047: That is,
                   1048: even though the
                   1049: buffer wasn't visible it was still receiving output from the process.
                   1050: You don't have to worry about missing anything when the buffer isn't visible.
                   1051: .NH 2
                   1052: Advantages of Running Processes in \s-2JOVE\s0 Windows.
                   1053: .XS \n(PN 5n
                   1054: \*(SN Advantages of Running Processes in \s-2JOVE\s0 Windows.
                   1055: .XE
                   1056: .LP
                   1057: There are several advantages to running a shell in a window.
                   1058: What you type isn't seen immediately by the process;
                   1059: instead \s-2JOVE\s0 waits until
                   1060: you type an entire line before passing it on to the process to read.
                   1061: This means that before you type <return>
                   1062: all of \s-2JOVE\s0's editing
                   1063: capabilities are available for fixing errors on your input line.
                   1064: If you discover an error at the beginning of the line,
                   1065: rather than erasing the whole line and starting over,
                   1066: you can simply move to the error,
                   1067: correct it,
                   1068: move back and continue typing.
                   1069: .LP
                   1070: Another feature is that you have the entire history of your session in
                   1071: a \s-2JOVE\s0 buffer.
                   1072: You don't have to worry about output from a command
                   1073: moving past the top of the screen.
                   1074: If you missed some output you can
                   1075: move back through it with ESC V and other commands.
                   1076: In addition,
                   1077: you can save yourself retyping a command (or a similar one) by sending
                   1078: edited versions of previous commands, or edit the output of one command
                   1079: to become a list of commands to be executed ("immediate shell scripts").
                   1080: .NH 2
                   1081: Differences between Normal and I-process Buffers
                   1082: .XS \n(PN 5n
                   1083: \*(SN Differences between Normal and I-process Buffers
                   1084: .XE
                   1085: .LP
                   1086: \s-2JOVE\s0 behaves differently in several ways when you are in an \fIi-process\fP
                   1087: buffer.
                   1088: Most obviously, <return> does different things
                   1089: depending on both your position in the buffer and on the state of the process.
                   1090: In the normal case,
                   1091: when point is at the end of the buffer,
                   1092: Return does what you'd expect: it inserts a line-separator and then
                   1093: sends the line to the process.
                   1094: If you are somewhere else in the buffer,
                   1095: possibly positioned at a previous command that you want to edit,
                   1096: Return will place a copy of that line
                   1097: (with the prompt discarded if there is one)
                   1098: at the end of the buffer and move you there.
                   1099: Then you can edit the line and type Return as in the normal case.
                   1100: If the process has died for some reason,
                   1101: Return does nothing.
                   1102: It doesn't even insert itself.
                   1103: If that happens unexpectedly,
                   1104: you should type ESC X \fIlist-processes\fP<return>
                   1105: to get a list of each process and its state.
                   1106: If your process died abnormally,
                   1107: \fIlist-processes\fP may help you figure out why.
                   1108: .NH 2
                   1109: How to Run a Shell in a Window
                   1110: .XS \n(PN 5n
                   1111: \*(SN How to Run a Shell in a Window
                   1112: .XE
                   1113: .LP
                   1114: Type ESC X \fIshell\fP<return> to start up a shell.
                   1115: As with C-X !,
                   1116: \s-2JOVE\s0 will
                   1117: create a buffer,
                   1118: called \fB*shell*\-1\fP,
                   1119: and select a window for this new buffer.
                   1120: But unlike C-X ! you will be left in the new window.
                   1121: Now,
                   1122: the shell process is said to be attached to \fBshell\-1\fP.

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