Annotation of 43BSDReno/share/doc/usd/17.jove/jove.2, revision 1.1.1.1

1.1       root        1: .\"    @(#)jove.2      6.1 (Berkeley) 5/30/86
                      2: .\"
                      3: .NH 1
                      4: Commands for English Text
                      5: .XS \n(PN
                      6: \*(SN Commands for English Text
                      7: .XE
                      8: .LP
                      9: \s-2JOVE\s0 has many commands that work on the basic units of English text:
                     10: words, sentences and paragraphs.
                     11: .NH 2
                     12: Word Commands
                     13: .XS \n(PN 5n
                     14: \*(SN Word Commands
                     15: .XE
                     16: .LP
                     17: \s-2JOVE\s0 has commands for moving over or operating on words.
                     18: By convention,
                     19: they are all ESC commands.
                     20: .IP "ESC F" 20n
                     21: Move Forward over a word.
                     22: .IP "ESC B" 20n
                     23: Move Backward over a word.
                     24: .IP "ESC D" 20n
                     25: Kill forward to the end of a word.
                     26: .IP "ESC Rubout" 20n
                     27: Kill backward to the beginning of a word.
                     28: .LP
                     29: Notice how these commands form a group that parallels the character-
                     30: based commands,
                     31: C-F,
                     32: C-B,
                     33: C-D,
                     34: and Rubout.
                     35: .LP
                     36: The commands ESC F and ESC B move forward and backward over words.
                     37: They are thus analogous to Control-F and Control-B,
                     38: which move over single characters.
                     39: Like their Control- analogues,
                     40: ESC F and ESC B move several words if given an argument.
                     41: ESC F with a negative argument moves backward like ESC B,
                     42: and ESC B with a negative argument moves forward.
                     43: Forward motion stops right after the last letter of the word,
                     44: while backward motion stops right before the first letter.
                     45: .LP
                     46: It is easy to kill a word at a time.
                     47: ESC D kills the word after point.
                     48: To be precise,
                     49: it kills everything from point to the place ESC F would move to.
                     50: Thus,
                     51: if point is in the middle of a word,
                     52: only the part after point is killed.
                     53: If some punctuation comes after point,
                     54: and before the next word,
                     55: it is killed along with the word.
                     56: If you wish to kill only the next word but not the punctuation,
                     57: simply do ESC F to get to the end,
                     58: and kill the word backwards with ESC Rubout.
                     59: ESC D takes arguments just like ESC F.
                     60: .LP
                     61: ESC Rubout kills the word before point.
                     62: It kills everything from point back to where ESC B would move to.
                     63: If point is after the space in "FOO, BAR",
                     64: then "FOO, " is killed.
                     65: If you wish to kill just "FOO",
                     66: then do a ESC B and a ESC D instead of a ESC Rubout.
                     67: .NH 2
                     68: Sentence Commands
                     69: .XS \n(PN 5n
                     70: \*(SN Sentence Commands
                     71: .XE
                     72: .LP
                     73: The \s-2JOVE\s0 commands for manipulating sentences and paragraphs are
                     74: mostly ESC commands,
                     75: so as to resemble the word-handling commands.
                     76: .IP "ESC A" 20n
                     77: Move back to the beginning of the sentence.
                     78: .IP "ESC E" 20n
                     79: Move forward to the end of the sentence.
                     80: .IP "ESC K" 20n
                     81: Kill forward to the end of the sentence.
                     82: .IP "C-X Rubout" 20n
                     83: Kill back to the beginning of the sentence.
                     84: .LP
                     85: The commands ESC A and ESC E move to the beginning and end of the
                     86: current sentence,
                     87: respectively.
                     88: They were chosen to resemble
                     89: Control-A and Control-E,
                     90: which move to the beginning and end of a line.
                     91: Unlike them,
                     92: ESC A and ESC E if repeated or given numeric arguments
                     93: move over successive sentences.
                     94: \s-2JOVE\s0 considers a sentence to end wherever there is a ".",
                     95: "?", or "!" followed by the end of a line
                     96: or by one or more spaces.
                     97: Neither ESC A nor ESC E moves past the
                     98: end of the line or spaces which delimit the sentence.
                     99: .LP
                    100: Just as C-A and C-E have a kill command,
                    101: C-K,
                    102: to go with them,
                    103: so ESC A and ESC E have a corresponding kill command ESC K which kills from
                    104: point to the end of the sentence.
                    105: With minus one as an argument it
                    106: kills back to the beginning of the sentence.
                    107: Positive arguments serve as a repeat count.
                    108: .LP
                    109: There is a special command,
                    110: C-X Rubout for killing back to the beginning of a sentence,
                    111: because this is useful when you change your
                    112: mind in the middle of composing text.
                    113: .NH 2
                    114: Paragraph Commands
                    115: .XS \n(PN 5n
                    116: \*(SN Paragraph Commands
                    117: .XE
                    118: .LP
                    119: The \s-2JOVE\s0 commands for handling paragraphs are
                    120: .IP "ESC [" 20n
                    121: Move back to previous paragraph beginning.
                    122: .IP "ESC ]" 20n
                    123: Move forward to next paragraph end.
                    124: .LP
                    125: ESC [ moves to the beginning of the current or previous paragraph, while
                    126: ESC ] moves to the end of the current or next paragraph.  Paragraphs are
                    127: delimited by lines of differing indent, or lines with text formatter
                    128: commands, or blank lines.  \s-2JOVE\s0 knows how to deal with most indented
                    129: paragraphs correctly, although it can get confused by one- or two-line
                    130: paragraphs delimited only by indentation.
                    131: .NH 2
                    132: Text Indentation Commands
                    133: .XS \n(PN 5n
                    134: \*(SN Text Indentation Commands
                    135: .XE
                    136: .LP
                    137: .IP "Tab" 20n
                    138: Indent "appropriately" in a mode-dependent fashion.
                    139: .IP "LineFeed" 20n
                    140: Is the same as Return,
                    141: except it copies the indent of the line you just left.
                    142: .IP "ESC M" 20n
                    143: Moves to the line's first non-blank character.
                    144: .LP
                    145: .LP
                    146: The way to request indentation is with the Tab command.
                    147: Its precise effect depends on the major mode.
                    148: In \fIText\fP mode,
                    149: it indents to the next tab stop.
                    150: In \fIC\fP mode,
                    151: it indents to the "right" position for C programs.
                    152: .LP
                    153: To move over the indentation on a line,
                    154: do ESC M (\fIfirst-non-blank\fP).
                    155: This command,
                    156: given anywhere on a line,
                    157: positions the cursor at the first non-blank, non-tab character on the line.
                    158: .NH 2
                    159: Text Filling
                    160: .XS \n(PN 5n
                    161: \*(SN Text Filling
                    162: .XE
                    163: .LP
                    164: \fIAuto Fill\fP mode causes text to be \fIfilled\fP
                    165: (broken up into lines that fit in a specified width)
                    166: automatically as you type it in.
                    167: If you alter existing text so that it is no longer properly filled,
                    168: \s-2JOVE\s0 can fill it again if you ask.
                    169: .LP
                    170: Entering \fIAuto Fill\fP mode is done with ESC X \fIauto-fill-mode\fP.
                    171: From then on,
                    172: lines are broken automatically at spaces when they get longer than the
                    173: desired width.
                    174: To leave \fIAuto Fill\fP mode,
                    175: once again execute ESC X \fIauto-fill-mode\fP.
                    176: When \fIAuto Fill\fP mode is in effect,
                    177: the word \fBFill\fP appears in the mode line.
                    178: .LP
                    179: If you edit the middle of a paragraph,
                    180: it may no longer correctly be filled.
                    181: To refill a paragraph,
                    182: use the command ESC J (\fIfill-paragraph\fP).
                    183: It causes the paragraph that point is inside to be filled.
                    184: All the line breaks are removed and new ones inserted where necessary.
                    185: .LP
                    186: The maximum line width for filling is in the variable \fIright-margin\fP.
                    187: Both ESC J and auto-fill make sure that no line exceeds this width.
                    188: The value of \fIright-margin\fP is initially 72.
                    189: .LP
                    190: Normally ESC J figures out the indent of the paragraph and uses that same
                    191: indent when filling.  If you want to change the indent of a paragraph you
                    192: set \fIleft-margin\fP to the new position and type C-U\ ESC\ J.
                    193: \fIfill-paragraph\fP, when supplied a numeric argument, uses the value of
                    194: \fIleft-margin\fP.
                    195: .LP
                    196: If you know where you want to set the right margin but you don't know the
                    197: actual value, move to where you want to set the value and use the
                    198: \fIright-margin-here\fP command.  \fIleft-margin-here\fP does the same
                    199: for the \fIleft-margin\fP variable.
                    200: .NH 2
                    201: Case Conversion Commands
                    202: .XS \n(PN 5n
                    203: \*(SN Case Conversion Commands
                    204: .XE
                    205: .LP
                    206: .IP "ESC L" 15n
                    207: Convert following word to lower case.
                    208: .IP "ESC U" 15n
                    209: Convert following word to upper case.
                    210: .IP "ESC C" 15n
                    211: Capitalize the following word.
                    212: .LP
                    213: .LP
                    214: The word conversion commands are most useful.
                    215: ESC L converts the word after point to lower case,
                    216: moving past it.
                    217: Thus,
                    218: successive ESC L's convert successive words.
                    219: ESC U converts to all capitals instead,
                    220: while ESC C puts the first letter of the word into upper case and the
                    221: rest into lower case.
                    222: All these commands convert several words at once if given an argument.
                    223: They are especially convenient for
                    224: converting a large amount of text from all upper case to mixed case,
                    225: because you can move through the test using ESC L,
                    226: ESC U or ESC C on each word as appropriate.
                    227: .LP
                    228: When given a negative argument,
                    229: the word case conversion commands apply to
                    230: the appropriate number of words before point,
                    231: but do not move point.
                    232: This is convenient when you have just typed a word in the wrong case.
                    233: You can give the case conversion command and continue typing.
                    234: .LP
                    235: If a word case conversion command is given in the middle of a word,
                    236: it applies only to the part of the word which follows the cursor,
                    237: treating it as a whole word.
                    238: .LP
                    239: The other case conversion functions are \fIcase-region-upper\fP and
                    240: \fIcase-region-lower\fP,
                    241: which convert everything between point and mark to the specified case.
                    242: Point and mark remain unchanged.
                    243: .NH 2
                    244: Commands for Fixing Typos
                    245: .XS \n(PN 5n
                    246: \*(SN Commands for Fixing Typos
                    247: .XE
                    248: .LP
                    249: In this section we describe the commands that are especially useful
                    250: for the times when you catch a mistake on your text after you have made it,
                    251: or change your mind while composing text on line.
                    252: .IP "Rubout" 25n
                    253: Delete last character.
                    254: .IP "ESC Rubout" 25n
                    255: Kill last word.
                    256: .IP "C-X Rubout" 25n
                    257: Kill to beginning of sentence.
                    258: .IP "C-T" 25n
                    259: Transpose two characters.
                    260: .IP "C-X C-T" 25n
                    261: Transpose two lines.
                    262: .IP "ESC Minus ESC L" 25n
                    263: Convert last word to lower case.
                    264: .IP "ESC Minus ESC U" 25n
                    265: Convert last word to upper case.
                    266: .IP "ESC Minus ESC C" 25n
                    267: Convert last word to lower case with capital initial.
                    268: .LP
                    269: .NH 2
                    270: Killing Your Mistakes
                    271: .XS \n(PN 5n
                    272: \*(SN Killing Your Mistakes
                    273: .XE
                    274: .LP
                    275: The Rubout command is the most important correction command.
                    276: When used among printing (self-inserting) characters,
                    277: it can be thought of as canceling the last character typed.
                    278: .LP
                    279: When your mistake is longer than a couple of characters,
                    280: it might be more convenient to use ESC Rubout or C-X Rubout.
                    281: ESC Rubout kills back to the start of the last word,
                    282: and C-X Rubout kills back to the start of the last sentence.
                    283: C-X Rubout is particularly useful when
                    284: you are thinking of what to write as you type it,
                    285: in case you change your mind about phrasing.
                    286: ESC Rubout and C-X Rubout save the killed text for C-Y and ESC Y to retrieve.
                    287: .LP
                    288: ESC Rubout is often useful even when you have typed only a few
                    289: characters wrong,
                    290: if you know you are confused in your typing and aren't sure what you typed.
                    291: At such a time,
                    292: you cannot correct with
                    293: Rubout except by looking at the screen to see what you did.
                    294: It requires less thought to kill the whole word and start over again,
                    295: especially if the system is heavily loaded.
                    296: .LP
                    297: If you were typing a command or command parameters, C-G will abort the
                    298: command with no further processing.
                    299: .NH 2
                    300: Transposition
                    301: .XS \n(PN 5n
                    302: \*(SN Transposition
                    303: .XE
                    304: .LP
                    305: The common error of transposing two characters can be fixed
                    306: with the C-T (\fItranspose-characters\fP) command.
                    307: Normally,
                    308: C-T transposes the two characters on either side of the cursor
                    309: and moves the cursor forward one character.  Repeating the command
                    310: several times "drags" a character to the right.
                    311: (Remember that \fIpoint\fP is considered to be between two characters,
                    312: even though the visible cursor in your terminal is on only one of them.)
                    313: When given at the end of a line,
                    314: rather than switching the last character of the line with the line separator,
                    315: which would be useless,
                    316: C-T transposes the last two characters on the line.
                    317: So,
                    318: if you catch your transposition error right away,
                    319: you can fix it with just a C-T.
                    320: If you don't catch it so fast,
                    321: you must move the cursor back to between the two characters.
                    322: .LP
                    323: To transpose two lines,
                    324: use the C-X C-T (\fItranspose-lines\fP) command.  The line containing the
                    325: cursor is exchanged with the line above it; the cursor is left at the
                    326: beginning of the line following its original position.
                    327: .NH 2
                    328: Checking and Correcting Spelling
                    329: .XS \n(PN 5n
                    330: \*(SN Checking and Correcting Spelling
                    331: .XE
                    332: .LP
                    333: When you write a paper,
                    334: you should correct its spelling at some point close to finishing it.
                    335: To correct the entire buffer,
                    336: do ESC X \fIspell-buffer\fP.
                    337: This invokes the
                    338: .UX
                    339: .I spell
                    340: program,
                    341: which prints a list of all the misspelled words.
                    342: \s-2JOVE\s0 catches the list and places it in a
                    343: \s-2JOVE\s0 buffer called \fBSpell\fP.
                    344: You are given an opportunity to delete from that buffer any words that
                    345: aren't really errors;
                    346: then \s-2JOVE\s0 looks up each misspelled word and
                    347: remembers where it is in the buffer being corrected.
                    348: Then you can go forward to each misspelled word with C-X C-N (\fInext-error\fP)
                    349: and backward with C-X C-P (\fIprevious-error\fP).
                    350: See the section entitled \fIError Message Parsing\fP.
                    351: .NH 1
                    352: File Handling
                    353: .XS \n(PN
                    354: \*(SN File Handling
                    355: .XE
                    356: .LP
                    357: The basic unit of stored data is the file.
                    358: Each program,
                    359: each paper,
                    360: lives usually in its own file.
                    361: To edit a program or paper,
                    362: the editor must be told the name of the file that contains it.
                    363: This is called \fIvisiting\fP a file.
                    364: To make your changes to the file permanent on disk,
                    365: you must \fIsave\fP the file.
                    366: .NH 2
                    367: Visiting Files
                    368: .XS \n(PN 5n
                    369: \*(SN Visiting Files
                    370: .XE
                    371: .LP
                    372: .IP "C-X C-V" 15n
                    373: Visit a file.
                    374: .IP "C-X C-R" 15n
                    375: Same as C-X C-V.
                    376: .IP "C-X C-S" 15n
                    377: Save the visited file.
                    378: .IP "ESC ~" 15n
                    379: Tell \s-2JOVE\s0 to forget that the buffer has been changed.
                    380: .LP
                    381: .LP
                    382: \fIVisiting\fP a file means copying its contents into \s-2JOVE\s0 where you
                    383: can edit them.
                    384: \s-2JOVE\s0 remembers the name of the file you visited.
                    385: Unless you use the multiple buffer feature of \s-2JOVE\s0,
                    386: you can only be visiting one file at a time.
                    387: The name of the current selected buffer is visible in the mode line.
                    388: .LP
                    389: The changes you make with \s-2JOVE\s0 are made in a copy inside \s-2JOVE\s0.
                    390: The file itself is not changed.
                    391: The changed text is not permanent until you \fIsave\fP it in a file.
                    392: The first time you change the text,
                    393: an asterisk appears at the end of the mode line; this indicates that the text
                    394: contains fresh changes which will be lost unless you save them.
                    395: .LP
                    396: To visit a file,
                    397: use the command C-X C-V.
                    398: Follow the command with the name of the file you wish to visit,
                    399: terminated by a Return.
                    400: You can abort the command by typing C-G,
                    401: or edit the filename with many of the standard \s-2JOVE\s0 commands
                    402: (e.g., C-A, C-E, C-F, ESC F, ESC Rubout).
                    403: If the filename you wish to visit is similar to the filename in the
                    404: mode line (the default filename),
                    405: you can type C-R to insert the default and then edit it.
                    406: If you do type a Return to finish the command,
                    407: the new file's text appears on the screen,
                    408: and its name appears in the mode line.
                    409: In addition,
                    410: its name becomes the new default filename.
                    411: .LP
                    412: If you wish to save the file and make your changes permanent,
                    413: type C-X C-S.
                    414: After the save is finished,
                    415: C-X C-S prints the filename and the
                    416: number of characters and lines that it wrote to the file.
                    417: If there are no changes to save (no asterisk at the end of the mode line),
                    418: the file is not saved;
                    419: otherwise the changes saved and the asterisk at the end of
                    420: the mode line will disappear.
                    421: .LP
                    422: What if you want to create a file?  Just visit it.
                    423: \s-2JOVE\s0 prints
                    424: \fI(New file)\fP but aside from that behaves as if you had visited an existing
                    425: empty file.
                    426: If you make any changes and save them,
                    427: the file is created.
                    428: If you visit a nonexistent file unintentionally
                    429: (because you typed the wrong filename),
                    430: go ahead and visit the file you meant.
                    431: If you don't save the unwanted file,
                    432: it is not created.
                    433: .LP
                    434: If you alter one file and then visit another in the same buffer,
                    435: \s-2JOVE\s0 offers to save the old one.
                    436: If you answer YES,
                    437: the old file is saved;
                    438: if you answer NO,
                    439: all the changes you have made to it since the last save are lost.
                    440: You should not type ahead after a file visiting
                    441: command,
                    442: because your type-ahead might answer an unexpected question
                    443: in a way that you would regret.
                    444: .LP
                    445: Sometimes you will change a buffer by accident.
                    446: Even if you undo the effect of the change by editing,
                    447: \s-2JOVE\s0 still knows that "the buffer has been changed".
                    448: You can tell \s-2JOVE\s0 to pretend that there have been no changes with the
                    449: ESC \s+2~\s0 command (\fImake-buffer-unmodified\fP).
                    450: This command simply clears the "modified" flag which
                    451: says that the buffer contains changes which need to be saved.
                    452: Even if
                    453: the buffer really \fIis\fP changed \s-2JOVE\s0 will still act as if it were not.
                    454: .LP
                    455: If \s-2JOVE\s0 is about to save a file and sees that the date of the version
                    456: on disk does not match what \s-2JOVE\s0 last read or wrote,
                    457: \s-2JOVE\s0 notifies you of this fact,
                    458: and asks what to do, because this probably means that something is wrong.
                    459: For example,
                    460: somebody else may have been editing the same file.
                    461: If this is so,
                    462: there is a good chance that your work
                    463: or his work will be lost if you don't take the proper steps.
                    464: You should first find out exactly what is going on.
                    465: If you determine that somebody else has modified the file,
                    466: save your file under a different filename and then DIFF the two files
                    467: to merge the two sets of changes.  (The "patch" command is useful for
                    468: applying the results of context diffs directly).
                    469: Also get in touch with the other person so that the files don't diverge
                    470: any further.
                    471: .NH 2
                    472: How to Undo Drastic Changes to a File
                    473: .XS \n(PN 5n
                    474: \*(SN How to Undo Drastic Changes to a File
                    475: .XE
                    476: .LP
                    477: If you have made several extensive changes to a file and then change
                    478: your mind about them,
                    479: and you haven't yet saved them,
                    480: you can get rid of them by reading in the previous version of the file.
                    481: You can do this with the C-X C-V command,
                    482: to visit the unsaved version of the file.
                    483: .NH 2
                    484: Recovering from system/editor crashes
                    485: .XS \n(PN 5n
                    486: \*(SN Recovering from system/editor crashes
                    487: .XE
                    488: .LP
                    489: JOVE does not have \fIAuto Save\fP mode, but it does provide a way to
                    490: recover your work in the event of a system or editor crash.  JOVE saves
                    491: information about the files you're editing every so many changes to a
                    492: buffer to make recovery possible.  Since a relatively small amount of
                    493: information is involved it's hardly even noticeable when JOVE does this.  The
                    494: variable "sync-frequency" says how often to save the necessary
                    495: information, and the default is every 50 changes.  50 is a very
                    496: reasonable number: if you are writing a paper you will not lose more than
                    497: the last 50 characters you typed, which is less than the average length
                    498: of a line.
                    499: .NH 2
                    500: Miscellaneous File Operations
                    501: .XS \n(PN 5n
                    502: \*(SN Miscellaneous File Operations
                    503: .XE
                    504: .LP
                    505: .LP
                    506: ESC X \fIwrite-file\fP <file><return> writes the contents of the buffer
                    507: into the file <file>,
                    508: and then visits that file.
                    509: It can be thought of as a way of "changing the name" of
                    510: the file you are visiting.
                    511: Unlike C-X C-S,
                    512: \fIwrite-file\fP saves even if the buffer has not been changed.
                    513: C-X C-W is another way of getting this command.
                    514: .LP
                    515: ESC X \fIinsert-file\fP <file><return> inserts the contents of <file> into the
                    516: buffer at point,
                    517: leaving point unchanged before the contents.
                    518: You can also use C-X C-I to get this command.
                    519: .LP
                    520: ESC X \fIwrite-region\fP <file><return> writes the region (the text between
                    521: point and mark) to the specified file.
                    522: It does not set the visited filename.
                    523: The buffer is not changed.
                    524: .LP
                    525: ESC X \fIappend-region\fP <file><return> appends the region to <file>.
                    526: The text is added to the end of <file>.
                    527: .NH 1
                    528: Using Multiple Buffers
                    529: .XS \n(PN
                    530: \*(SN Using Multiple Buffers
                    531: .XE
                    532: .LP
                    533: When we speak of "the buffer",
                    534: which contains the text you are editing,
                    535: we have given the impression that there is only one.
                    536: In fact,
                    537: there may be many of them,
                    538: each with its own body of text.
                    539: At any time only one buffer can be \fIselected\fP and available for editing,
                    540: but it isn't hard to switch to a different one.
                    541: Each buffer individually remembers which file it is visiting,
                    542: what modes are in effect,
                    543: and whether there are any changes that need saving.
                    544: .IP "C-X B" 15n
                    545: Select or create a buffer.
                    546: .IP "C-X C-F" 15n
                    547: Visit a file in its own buffer.
                    548: .IP "C-X C-B" 15n
                    549: List the existing buffers.
                    550: .IP "C-X K" 15n
                    551: Kill a buffer.
                    552: .LP
                    553: Each buffer in \s-2JOVE\s0 has a single name,
                    554: which normally doesn't change.
                    555: A buffer's name can be any length.
                    556: The name of the currently selected buffer
                    557: and the name of the file visited in it
                    558: are visible in the mode line when you are at top level.
                    559: A newly started \s-2JOVE\s0 has only one buffer,
                    560: named \fBMain\fP, unless you specified files to edit in the
                    561: shell command that started \s-2JOVE\s0.
                    562: .NH 2
                    563: Creating and Selecting Buffers
                    564: .XS \n(PN 5n
                    565: \*(SN Creating and Selecting Buffers
                    566: .XE
                    567: .LP
                    568: To create a new buffer,
                    569: you need only think of a name for it (say, FOO)
                    570: and then do C-X B FOO<return>,
                    571: which is the command C-X B (\fIselect-buffer\fP) followed by the name.
                    572: This makes a new,
                    573: empty buffer (if one by that name didn't previously exist) 
                    574: and selects it for editing.
                    575: The new buffer is not visiting any file,
                    576: so if you try to save it you will be asked for the filename to use.
                    577: Each buffer has its own major mode;
                    578: the new buffer's major mode is \fIText\fP mode by default.
                    579: .LP
                    580: To return to buffer FOO later after having switched to another,
                    581: the same command C-X B FOO<return> is used,
                    582: since C-X B can tell whether a buffer named FOO exists already or not.
                    583: C-X B Main<return> reselects the buffer Main that \s-2JOVE\s0 started out with.
                    584: Just C-X B<return> reselects the previous buffer.
                    585: Repeated C-X B<return>'s alternate between the last two buffers selected.
                    586: .LP
                    587: You can also read a file into its own newly created buffer,
                    588: all with one command: C-X C-F (\fIfind-file\fP),
                    589: followed by the filename.
                    590: The name of the buffer is the last element of the file's pathname.
                    591: C-F stands for "Find",
                    592: because if the specified file already resides in a buffer in your \s-2JOVE\s0,
                    593: that buffer is reselected.
                    594: So you need not remember whether you have brought the file in already or not.
                    595: A buffer created by C-X C-F can be reselected later with C-X B or C-X C-F,
                    596: whichever you find more convenient.
                    597: Nonexistent files can be created with C-X C-F just as they can with C-X C-V.
                    598: .NH 2
                    599: Using Existing Buffers
                    600: .XS \n(PN 5n
                    601: \*(SN Using Existing Buffers
                    602: .XE
                    603: .LP
                    604: To get a list of all the buffers that exist,
                    605: do C-X C-B (\fIlist-buffers\fP).
                    606: Each buffer's type,
                    607: name,
                    608: and visited filename is printed.
                    609: An asterisk before the buffer name indicates a
                    610: buffer which contains changes that have not been saved. The number
                    611: that appears at the beginning of a line in a C-X C-B listing is that
                    612: buffer's \fIbuffer number\fP.
                    613: You can select a buffer by typing its number in place of its name.
                    614: If a buffer with that number doesn't already exist,
                    615: a new buffer is created with that number as its name.
                    616: .LP
                    617: If several buffers have modified text in them,
                    618: you should save some of them with C-X C-M (\fIwrite-modified-files\fP).
                    619: This finds all the buffers that need saving and then saves them.
                    620: Saving the buffers this way is much
                    621: easier and more efficient (but more dangerous)
                    622: than selecting each one and typing C-X C-S.
                    623: If you give C-X C-M an argument, \s-2JOVE\s0 will ask for confirmation
                    624: before saving each buffer.
                    625: .LP
                    626: ESC X \fIrename-buffer\fP <new name><return> changes the name of the currently
                    627: selected buffer.
                    628: .LP
                    629: ESC X \fIerase-buffer\fP <buffer name><return> erases the contents of the
                    630: <buffer name> without deleting the buffer entirely.
                    631: .NH 2
                    632: Killing Buffers
                    633: .XS \n(PN 5n
                    634: \*(SN Killing Buffers
                    635: .XE
                    636: .LP
                    637: After you use a \s-2JOVE\s0 for a while,
                    638: it may fill up with buffers which you no longer need.
                    639: Eventually you can reach a point where trying to
                    640: create any more results in an "out of memory" or "out of lines"
                    641: error.
                    642: When this happens you will want to kill some buffers with the
                    643: C-X K (\fIdelete-buffer\fP) command.
                    644: You can kill the buffer FOO by doing C-X K FOO<return>.
                    645: If you type C-X K <return> JOVE will kill the previously selected buffer.
                    646: If you try to kill a buffer that needs saving \s-2JOVE\s0
                    647: will ask you to confirm it.
                    648: .LP
                    649: If you need to kill several buffers, use the command \fIkill-some-buffers\fP.
                    650: This prompts you with the name of each buffer and asks for confirmation
                    651: before killing that buffer.
                    652: .NH 1
                    653: Controlling the Display
                    654: .XS \n(PN
                    655: \*(SN Controlling the Display
                    656: .XE
                    657: .LP
                    658: Since only part of a large file will fit on the screen,
                    659: \s-2JOVE\s0 tries to show the part that is likely to be interesting.
                    660: The display control commands allow you to see a different part of the file.
                    661: .IP "C-L" 15n
                    662: Reposition point at a specified vertical position,
                    663: OR clear and redraw the screen with point in the same place.
                    664: .IP "C-V" 15n
                    665: Scroll forwards (a screen or a few lines).
                    666: .IP "ESC V" 15n
                    667: Scroll backwards.
                    668: .IP "C-Z" 15n
                    669: Scroll forward some lines.
                    670: .IP "ESC Z" 15n
                    671: Scroll backwards some lines.
                    672: .LP
                    673: .LP
                    674: The terminal screen is rarely large enough to display all of your
                    675: file.
                    676: If the whole buffer doesn't fit on the screen,
                    677: \s-2JOVE\s0 shows a contiguous portion of it,
                    678: containing 
                    679: .I point.
                    680: It continues to show approximately the same portion
                    681: until point moves outside of what is displayed;
                    682: then \s-2JOVE\s0 chooses a new portion centered around the new 
                    683: .I point.
                    684: This is \s-2JOVE\s0's guess as to what you are most interested in seeing,
                    685: but if the guess is wrong,
                    686: you can use the display control commands to see a different portion.
                    687: The available screen area through which you can see part of
                    688: the buffer is called \fIthe window\fP,
                    689: and the choice of where in the
                    690: buffer to start displaying is also called \fIthe window\fP.  (When 
                    691: there is only one window, it plus the mode line and the input line take
                    692: up the whole screen).
                    693: .LP
                    694: First we describe how \s-2JOVE\s0 chooses a new window position on its own.
                    695: The goal is usually to place 
                    696: .I point 
                    697: half way down the window.
                    698: This is controlled by the variable \fIscroll-step\fP,
                    699: whose value is the number of
                    700: lines above the bottom or below the top of the window that the line
                    701: containing point is placed.
                    702: A value of 0 (the initial value) means center 
                    703: .I point
                    704: in the window.
                    705: .LP
                    706: The basic display control command is C-L (\fIredraw-display\fP).
                    707: In its simplest form,
                    708: with no argument,
                    709: it tells \s-2JOVE\s0 to choose a new window position,
                    710: centering point half way from the top as usual.
                    711: .LP
                    712: C-L with a positive argument chooses a new window so as to put point
                    713: that many lines from the top.
                    714: An argument of zero puts point on the very top line.
                    715: Point does not move with respect to the text; rather,
                    716: the text and point move rigidly on the screen.
                    717: .LP
                    718: If point stays on the same line,
                    719: the window is first cleared and then redrawn.
                    720: Thus,
                    721: two C-L's in a row are guaranteed to clear the current window.
                    722: ESC C-L will clear and redraw the entire screen.
                    723: .LP
                    724: The \fIscrolling\fP commands C-V,
                    725: ESC V,
                    726: C-Z,
                    727: and ESC Z,
                    728: let you move the whole display up or down a few lines.
                    729: C-V (\fInext-page\fP) with an
                    730: argument shows you that many more lines at the bottom of the screen,
                    731: moving the text and point up together as C-L might.
                    732: C-V with a
                    733: negative argument shows you more lines at the top of the screen,
                    734: as does ESC V (\fIprevious-page\fP) with a positive argument.
                    735: .LP
                    736: To read the buffer a window at a time,
                    737: use the C-V command with no argument.
                    738: It takes the last line at the bottom of the window and puts
                    739: it at the top,
                    740: followed by nearly a whole window of lines not visible before.
                    741: Point is put at the top of the window.
                    742: Thus, each C-V shows the "next page of text",
                    743: except for one line of overlap to provide context.
                    744: To move backward,
                    745: use ESC V without an argument,
                    746: which moves a whole window backwards (again with a line of overlap).
                    747: .LP
                    748: C-Z and ESC Z scroll one line forward and one line backward,
                    749: respectively.
                    750: These are convenient for moving in units of lines
                    751: without having to type a numeric argument.
                    752: .NH 2
                    753: Multiple Windows
                    754: .XS \n(PN 5n
                    755: \*(SN Multiple Windows
                    756: .XE
                    757: .LP
                    758: \s-2JOVE\s0 allows you to split the screen into two or more \fIwindows\fP and
                    759: use them to display parts of different files,
                    760: or different parts of the same file.
                    761: .IP "C-X 2" 15n
                    762: Divide the current window into two smaller ones.
                    763: .IP "C-X 1" 15n
                    764: Delete all windows but the current one.
                    765: .IP "C-X D" 15n
                    766: Delete current window.
                    767: .IP "C-X N" 15n
                    768: Switch to the next window.
                    769: .IP "C-X P" 15n
                    770: Switch to the previous window.
                    771: .IP "C-X O" 15n
                    772: Same as C-X P.
                    773: .IP "C-X ^" 15n
                    774: Make this window bigger.
                    775: .IP "ESC C-V" 15n
                    776: Scroll the other window.
                    777: .LP
                    778: .LP
                    779: When using \fImultiple window\fP mode,
                    780: the text portion of the screen
                    781: is divided into separate parts called \fIwindows\fP,
                    782: which can display different pieces of text.
                    783: Each window can display different files,
                    784: or parts of the same file.
                    785: Only one of the windows is 
                    786: .I active; 
                    787: that is
                    788: the window which the cursor is in.
                    789: Editing normally takes place in that window alone.
                    790: To edit in another window,
                    791: you would give a command to move the cursor to the other window,
                    792: and then edit there.
                    793: .LP
                    794: Each window displays a mode line for the buffer it's displaying.
                    795: This is useful to keep track of which window corresponds with which
                    796: file.  In addition, the mode line serves as a separator between windows.
                    797: By setting the variable \fImode-line-should-standout\fP to "on" you can
                    798: have \s-2JOVE\s0 display the mode-line in reverse video (assuming your
                    799: particular terminal has the reverse video capability).
                    800: .LP
                    801: The command C-X 2 (\fIsplit-current-window\fP) enters multiple window mode.
                    802: A new mode line appears across the middle of the screen,
                    803: dividing the text display area into two halves.
                    804: Both windows contain the same buffer and display the same position in it,
                    805: namely where point was at the time you issued the command.
                    806: The cursor moves to the second window.
                    807: .LP
                    808: To return to viewing only one window,
                    809: use the command C-X 1 (\fIdelete-other-windows\fP).
                    810: The current window expands to fill the whole screen,
                    811: and the other windows disappear until the next C-X 2.
                    812: (The buffers and their contents are unaffected by any of the
                    813: window operations).
                    814: .LP
                    815: While there is more than one window,
                    816: you can use C-X N (\fInext-window\fP) to switch to the next window,
                    817: and C-X P (\fIprevious-window\fP) to switch to the previous one.
                    818: If you are in the bottom window and you type C-X N,
                    819: you will be placed in the top window,
                    820: and the same kind of thing happens when you type C-X P in the top window,
                    821: namely you will be placed in the bottom window.
                    822: C-X O is the same as C-X P.
                    823: It stands for "other window" because when there are only two windows,
                    824: repeated use of this command will switch between the two windows.
                    825: .LP
                    826: Often you will be editing one window while using the other just for reference.
                    827: Then,
                    828: the command ESC C-V (\fIpage-next-window\fP) is very useful.
                    829: It scrolls the next window,
                    830: as if you switched to the next window,
                    831: typed C-V,
                    832: and switched back,
                    833: without your having to do all that.
                    834: With a negative argument,
                    835: ESC C-V will do an ESC V in the next window.
                    836: .LP
                    837: When a window splits,
                    838: both halves are approximately the same size.
                    839: You can redistribute the screen space between the windows with
                    840: the C-X ^ (\fIgrow-window\fP) command.
                    841: It makes the currently selected window grow one line bigger,
                    842: or as many lines as is specified with a numeric argument.
                    843: Use ESC X \fIshrink-window\fP to make the current window smaller.
                    844: .NH 2
                    845: Multiple Windows and Multiple Buffers
                    846: .XS \n(PN 5n
                    847: \*(SN Multiple Windows and Multiple Buffers
                    848: .XE
                    849: .LP
                    850: Buffers can be selected independently in each window.
                    851: The C-X B command selects a new buffer in whichever window contains
                    852: the cursor.
                    853: Other windows' buffers do not change.
                    854: .LP
                    855: You can view the same buffer in more than one window.
                    856: Although the same buffer appears in both windows,
                    857: they have different values of point,
                    858: so you can move around in one window while the other window
                    859: continues to show the same text.
                    860: Then,
                    861: having found one place you wish to refer to, you can go back into the
                    862: other window with C-X O or C-X P to make your changes.
                    863: .LP
                    864: If you have the same buffer in both windows,
                    865: you must beware of trying to visit a different file in one of
                    866: the windows with C-X C-V,
                    867: because if you bring a new file into this buffer,
                    868: it will replaced the old file in \fIboth\fP windows.
                    869: To view different files in different windows,
                    870: you must switch buffers in one of the windows first
                    871: (with C-X B or C-X C-F, perhaps).
                    872: .LP
                    873: A convenient "combination" command for viewing something in another
                    874: window is C-X 4 (\fIwindow-find\fP).
                    875: With this command you can ask to see any specified buffer,
                    876: file or tag in the other window.
                    877: Follow the C-X 4 with either B and a buffer name,
                    878: F and a filename,
                    879: or T and a tag name.
                    880: This switches to the other window and finds there what you specified.
                    881: If you were previously in one-window mode,
                    882: multiple-window mode is entered.
                    883: C-X 4 B is similar to C-X 2 C-X B.
                    884: C-X 4 F is similar to C-X 2 C-X C-F.
                    885: C-X 4 T is similar to C-X 2 C-X
                    886: T.
                    887: The difference is one of efficiency,
                    888: and also that C-X 4 works equally well if you are already using two windows.
                    889: .NH 1
                    890: Processes Under \s-2JOVE\s0
                    891: .XS \n(PN
                    892: \*(SN Processes Under \s-2JOVE\s0
                    893: .XE
                    894: .LP
                    895: Another feature in \s-2JOVE\s0 is its ability to interact with
                    896: .UX
                    897: in a useful way.
                    898: You can run other
                    899: .UX
                    900: commands from \s-2JOVE\s0 and catch their output in \s-2JOVE\s0 buffers.
                    901: In this chapter we will discuss the different
                    902: ways to run and interact with
                    903: .UX
                    904: commands.
                    905: .NH 2
                    906: Non-interactive
                    907: .UX
                    908: commands
                    909: .XS \n(PN 5n
                    910: \*(SN Non-interactive
                    911: .XE
                    912: .LP
                    913: To run a
                    914: .UX
                    915: command from \s-2JOVE\s0 just type "C-X !" followed by the name
                    916: of the command terminated with Return.
                    917: For example,
                    918: to get a list of all the users on the system,
                    919: you do:
                    920: .DS I
                    921: C-X ! who<return>
                    922: .DE
                    923: Then \s-2JOVE\s0 picks a reasonable buffer in which the output from the
                    924: command will be placed.
                    925: E.g.,
                    926: "who" uses a buffer called \fBwho\fP;
                    927: "ps alx" uses \fBps\fP;
                    928: and "fgrep -n foo *.c" uses \fBfgrep\fP.
                    929: If \s-2JOVE\s0
                    930: wants to use a buffer that already exists it first erases the old contents.
                    931: If the buffer it selects holds a file,
                    932: not output from a previous shell command,
                    933: you must first delete that buffer with C-X K.
                    934: .LP
                    935: Once \s-2JOVE\s0 has picked a buffer it puts that buffer in a window so you
                    936: can see the command's output as it is running.
                    937: If there is only one window \s-2JOVE\s0 will automatically make another one.
                    938: Otherwise,
                    939: \s-2JOVE\s0
                    940: tries to pick the most convenient window which isn't the current one.
                    941: .LP
                    942: It's not a good idea to type anything while the command is running.
                    943: There are two reasons for this:
                    944: .IP (i)
                    945: \s-2JOVE\s0 won't see the characters (thus won't execute them) until the
                    946: command finishes,
                    947: so you may forget what you've typed.
                    948: .IP (ii)
                    949: Although \s-2JOVE\s0 won't know what you've typed,
                    950: it 
                    951: .I will
                    952: know that you've typed something,
                    953: and then it will try to be "smart" and not update the
                    954: display until it's interpreted what you've typed.
                    955: But,
                    956: of course,
                    957: \s-2JOVE\s0 won't interpret what you type until the
                    958: .UX
                    959: command completes,
                    960: so you're left with the uneasy feeling you get when you
                    961: don't know what the hell the computer is doing*.
                    962: .FS
                    963: *This is a bug and should be fixed,
                    964: but probably won't be for a while.
                    965: .FE
                    966: .LP
                    967: If you want to interrupt the command for some reason (perhaps you
                    968: mistyped it, or you changed your mind) you can type C-].
                    969: Typing this
                    970: inside \s-2JOVE\s0 while a process is running is the same as typing C-C when
                    971: you are outside \s-2JOVE\s0,
                    972: namely the process stops in a hurry.
                    973: .LP
                    974: When the command finishes, \s-2JOVE\s0 puts you back in the window in which 
                    975: you started.
                    976: Then it prints a message indicating whether or not the command
                    977: completed successfully in its (the command's) opinion.
                    978: That is,
                    979: if the command had what it considers an error
                    980: (or you interrupt it with C-])
                    981: \s-2JOVE\s0 will print an appropriate message.
                    982: 
                    983: .NH 2
                    984: Limitations of Non-Interactive Processes
                    985: .XS \n(PN 5n
                    986: \*(SN Limitations of Non-Interactive Processes
                    987: .XE
                    988: .LP
                    989: The reason these are called non-interactive processes is that you
                    990: can't type any input to them; you can't interact with them; they can't
                    991: ask you questions because there is no way for you to answer.
                    992: For example,
                    993: you can't run a command interpreter (a shell), or 
                    994: .I mail
                    995: or 
                    996: .I crypt
                    997: with C-X ! because there is no way to provide it with input.
                    998: Remember that \s-2JOVE\s0 (not the process in the window)
                    999: is listening to your keyboard,
                   1000: and \s-2JOVE\s0 waits until the process dies before it looks at
                   1001: what you type.
                   1002: .LP
                   1003: C-X ! is useful for running commands that do some output and then exit.
                   1004: For example,
                   1005: it's very useful to use with the C compiler to
                   1006: catch compilation error messages (see Compiling C Programs),
                   1007: or with the \fIgrep\fP commands.
                   1008: .NH 2
                   1009: Interactive Processes \(em Run a Shell in a Window
                   1010: .XS \n(PN 5n
                   1011: \*(SN Interactive Processes \(em Run a Shell in a Window
                   1012: .XE
                   1013: .LP
                   1014: Some versions of \s-2JOVE\s0\(dg
                   1015: .FS
                   1016: \(dg For example, the version provided with 4.3BSD.
                   1017: .FE
                   1018: have the capability of running interactive
                   1019: processes.
                   1020: This is more useful than non-interactive processes for
                   1021: certain types of jobs:
                   1022: .IP (i)
                   1023: You can go off and do some editing while the command is running.
                   1024: This is useful for commands that do sporadic output and run for fairly long
                   1025: periods of time.
                   1026: .IP (ii)
                   1027: Unlike non-interactive processes,
                   1028: you can type input to these.
                   1029: In addition,
                   1030: you can edit what you type with the power of all the \s-2JOVE\s0
                   1031: commands \fIbefore\fP you send the input to the process.
                   1032: This is a really important feature,
                   1033: and is especially useful for running a shell in a window.
                   1034: .IP (iii)
                   1035: Because you can continue with normal editing while one of the
                   1036: processes is running,
                   1037: you can create a bunch of contexts and manage them
                   1038: (select them, delete them, or temporarily put them aside)
                   1039: with \s-2JOVE\s0's window and buffer mechanisms.
                   1040: .LP
                   1041: Although we may have given an image of processes being attached to 
                   1042: .I windows,
                   1043: in fact they are attached to 
                   1044: .I buffers.
                   1045: Therefore,
                   1046: once an \fIi-process\fP is running you can select another buffer into that window,
                   1047: or if you wish you can delete the window altogether.
                   1048: If you reselect that buffer later it will be up to date.
                   1049: That is,
                   1050: even though the
                   1051: buffer wasn't visible it was still receiving output from the process.
                   1052: You don't have to worry about missing anything when the buffer isn't visible.
                   1053: .NH 2
                   1054: Advantages of Running Processes in \s-2JOVE\s0 Windows.
                   1055: .XS \n(PN 5n
                   1056: \*(SN Advantages of Running Processes in \s-2JOVE\s0 Windows.
                   1057: .XE
                   1058: .LP
                   1059: There are several advantages to running a shell in a window.
                   1060: What you type isn't seen immediately by the process;
                   1061: instead \s-2JOVE\s0 waits until
                   1062: you type an entire line before passing it on to the process to read.
                   1063: This means that before you type <return>
                   1064: all of \s-2JOVE\s0's editing
                   1065: capabilities are available for fixing errors on your input line.
                   1066: If you discover an error at the beginning of the line,
                   1067: rather than erasing the whole line and starting over,
                   1068: you can simply move to the error,
                   1069: correct it,
                   1070: move back and continue typing.
                   1071: .LP
                   1072: Another feature is that you have the entire history of your session in
                   1073: a \s-2JOVE\s0 buffer.
                   1074: You don't have to worry about output from a command
                   1075: moving past the top of the screen.
                   1076: If you missed some output you can
                   1077: move back through it with ESC V and other commands.
                   1078: In addition,
                   1079: you can save yourself retyping a command (or a similar one) by sending
                   1080: edited versions of previous commands, or edit the output of one command
                   1081: to become a list of commands to be executed ("immediate shell scripts").
                   1082: .NH 2
                   1083: Differences between Normal and I-process Buffers
                   1084: .XS \n(PN 5n
                   1085: \*(SN Differences between Normal and I-process Buffers
                   1086: .XE
                   1087: .LP
                   1088: \s-2JOVE\s0 behaves differently in several ways when you are in an \fIi-process\fP
                   1089: buffer.
                   1090: Most obviously, <return> does different things
                   1091: depending on both your position in the buffer and on the state of the process.
                   1092: In the normal case,
                   1093: when point is at the end of the buffer,
                   1094: Return does what you'd expect: it inserts a line-separator and then
                   1095: sends the line to the process.
                   1096: If you are somewhere else in the buffer,
                   1097: possibly positioned at a previous command that you want to edit,
                   1098: Return will place a copy of that line
                   1099: (with the prompt discarded if there is one)
                   1100: at the end of the buffer and move you there.
                   1101: Then you can edit the line and type Return as in the normal case.
                   1102: If the process has died for some reason,
                   1103: Return does nothing.
                   1104: It doesn't even insert itself.
                   1105: If that happens unexpectedly,
                   1106: you should type ESC X \fIlist-processes\fP<return>
                   1107: to get a list of each process and its state.
                   1108: If your process died abnormally,
                   1109: \fIlist-processes\fP may help you figure out why.
                   1110: .NH 2
                   1111: How to Run a Shell in a Window
                   1112: .XS \n(PN 5n
                   1113: \*(SN How to Run a Shell in a Window
                   1114: .XE
                   1115: .LP
                   1116: Type ESC X \fIi-shell\fP<return> to start up a shell.
                   1117: As with C-X !,
                   1118: \s-2JOVE\s0 will
                   1119: create a buffer,
                   1120: called \fBshell\-1\fP,
                   1121: and select a window for this new buffer.
                   1122: But unlike C-X ! you will be left in the new window.
                   1123: Now,
                   1124: the shell process is said to be attached to \fBshell\-1\fP,
                   1125: and it is considered an \fIi-process\fP buffer.

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