![[BACK]](/cvsweb/icons/back.gif){kind=icon}
Return to m3 CVS log ![[TXT]](/cvsweb/icons/text.gif){kind=icon}
![[DIR]](/cvsweb/icons/dir.gif){kind=icon}
Up to [CSRG BSD Unix] / 43BSDReno / share / doc / usd / 24.troff|
Return to m3 CVS log | Up to [CSRG BSD Unix] / 43BSDReno / share / doc / usd / 24.troff |
1.1 root 1: .\" @(#)m3 6.2 (Berkeley) 4/17/86
2: .\"
3: .tr |
4: .rm mx
5: .mh
6: Tabs, Leaders, and Fields
7: .sc
8: Tabs and leaders.
9: The \s-1ASCII\s+1 horizontal tab character and the \s-1ASCII\s+1
10: \s-1SOH\s+1 (hereafter known as the \fIleader\fR character)
11: can both be used to generate either horizontal motion or
12: a string of repeated characters.
13: The length of the generated entity is governed
14: by internal \fItab stops\fR specifiable
15: with \fBta\fR.
16: The default difference is that tabs generate motion and leaders generate
17: a string of periods;
18: \fBtc\fR and \fBlc\fR
19: offer the choice of repeated character or motion.
20: There are three types of internal tab stops\(em\
21: \fIleft\fR adjusting, \fIright\fR adjusting,
22: and \fIcentering\fR.
23: In the following table:
24: \fID\fR is the distance from the current position on the \fIinput\fR line
25: (where a tab or leader was found)
26: to the next tab stop;
27: \fInext-string\fR consists
28: of the input characters following the tab (or leader) up to the next tab (or leader) or end of line;
29: and
30: \fIW\fR is the width of \fInext-string\fR.
31: .TS
32: center box;
33: c2|c2|c
34: c2|c2|c
35: c2|c2|l.
36: Tab Length of motion or Location of
37: type repeated characters \fInext-string\fR
38: _
39: Left \fID\fR Following \fID\fR
40: Right \fID\-W\fR Right adjusted within \fID\fR
41: Centered \fID\-W\(sl\fR2 Centered on right end of \fID\fR
42: .TE
43: The length of generated motion is allowed to be negative, but
44: that of a repeated character string cannot be.
45: Repeated character strings contain an integer number of characters, and
46: any residual distance is prepended as motion.
47: Tabs or leaders found after the last tab stop are ignored, but may be used
48: as \fInext-string\fR terminators.
49: .pg
50: Tabs and leaders are not interpreted in \fIcopy mode\fR.
51: \fB\et\fR and \fB\ea\fR always generate a non-interpreted
52: tab and leader respectively, and
53: are equivalent to actual tabs and leaders in \fIcopy mode\fR.
54: .sc
55: Fields.
56: A \fIfield\fR is contained between
57: a \fIpair\fR of \fIfield delimiter\fR characters,
58: and consists of sub-strings
59: separated by \fIpadding\fR indicator characters.
60: The field length is the distance on the
61: \fIinput\fR line from the position where the field begins to the next tab stop.
62: The difference between the total length of all the sub-strings
63: and the field length is incorporated as horizontal
64: padding space that is divided among the indicated
65: padding places.
66: The incorporated padding is allowed to be negative.
67: For example,
68: if the field delimiter is \fB#\fR and the padding indicator is \fB^\fR,
69: \fB#^\fIxxx\fB^\fIright\|\fB#\fR
70: specifies a right-adjusted string with the string \fIxxx\fR centered
71: in the remaining space.
72: .h1
73: .bt
74: \fB&ta\fI|Nt|...\fR 8n;|0.5in none E,\fBm\fR \
75: Set tab stops and types.
76: \fIt=\fBR\fR, right adjusting;
77: \fIt=\fBC\fR, centering;
78: \fIt\fR absent, left adjusting.
79: \*(TR tab stops are preset every 0.5in.;
80: \*(NR every 8 character widths.
81: The stop values are separated by spaces, and
82: a value preceded by \fB+\fR
83: is treated as an increment to the previous stop value.
84: .bt
85: \fB&tc\fI|c\fR none none E \
86: The tab repetition character becomes \fIc\fR,
87: or is removed specifying motion.
88: .bt
89: \fB&lc\fI|c\fR \fB.\fR none E \
90: The leader repetition character becomes \fIc\fR,
91: or is removed specifying motion.
92: .bt
93: \fB&fc\fI|a|b\fR off off - \
94: The field delimiter is set to \fIa\fR;
95: the padding indicator is set to the \fIspace\fR character or to
96: \fIb\fR, if given.
97: In the absence of arguments the field mechanism is turned off.
98: .mh
99: Input and Output Conventions and Character Translations
100: .sc
101: Input character translations.
102: Ways of inputting the graphic character set were
103: discussed in \(sc2.1.
104: The \s-1ASCII\s+1 control characters horizontal tab (\(sc9.1),
105: \s-1SOH\s+1 (\(sc9.1), and backspace (\(sc10.3) are discussed elsewhere.
106: The newline delimits input lines.
107: In addition,
108: \s-1STX\s+1, \s-1ETX\s+1, \s-1ENQ\s+1, \s-1ACK\s+1, and \s-1BEL\s+1
109: are accepted,
110: and may be used as delimiters or translated into a graphic with \fBtr\fR (\(sc10.5).
111: \fIAll\fR others are ignored.
112: .pg
113: The \fIescape\fR character \fB\e\fR
114: introduces \fIescape sequences\fR\(em\
115: causes the following character to mean
116: another character, or to indicate
117: some function.
118: A complete list of such sequences is given in the Summary and Index on page 6.
119: \fB\e\fR
120: should not be confused with the \s-1ASCII\s+1 control character \s-1ESC\s+1 of the
121: same name.
122: The escape character \fB\e\fR can be input with the sequence \fB\e\e\fR.
123: The escape character can be changed with \fBec\fR,
124: and all that has been said about the default \fB\e\fR becomes true
125: for the new escape character.
126: \fB\ee\fR can be used to print whatever the current escape character is.
127: If necessary or convenient, the escape mechanism may be turned off with \fBeo\fR,
128: and restored with \fBec\fR.
129: .h1
130: .bt
131: \fB&ec\fI|c\fR \fB\e\fR \fB\e\fR - \
132: Set escape character to \fB\e\fR, or to \fIc\fR, if given.
133: .bt
134: \fB&eo\fR on - - Turn escape mechanism off.
135: .sc
136: Ligatures.
137: .lg0
138: Five ligatures are available
139: in the current \*(TR character set \(em
140: \fB\(fi\fR, \fB\(fl\fR, \fB\(ff\fR, \fB\(Fi\fR, and \fB\(Fl\fR.
141: They may be input (even in \*(NR) by
142: \fB\e(fi\fR, \fB\e(fl\fR, \fB\e(ff\fR, \fB\e(Fi\fR, and \fB\e(Fl\fR respectively.
143: .lg
144: The ligature mode is normally on in \*(TR, and \fIautomatically\fR invokes
145: ligatures during input.
146: .h1
147: .bt
148: \fB&lg\fI|N\fR off;|on on - Ligature mode
149: is turned on if \fIN\fR is absent or non-zero,
150: and turned off if \fIN\(eq\^\fR0.
151: If \fIN\fR\(eq\^2, only the two-character ligatures are automatically invoked.
152: Ligature mode is inhibited for
153: request, macro, string, register, or file names,
154: and in \fIcopy mode\fR.
155: No effect in \*(NR.
156: .sc
157: Backspacing, underlining, overstriking, etc.
158: Unless in \fIcopy mode\fR, the \s-1ASCII\s+1 backspace character is replaced
159: by a backward horizontal motion having the width of the
160: space character.
161: Underlining as a form of line-drawing is discussed in \(sc12.4.
162: A generalized overstriking function is described in \(sc12.1.
163: .pg
164: \*(NR automatically underlines
165: characters in the \fIunderline\fR font,
166: specifiable with \fBuf\fR,
167: normally Times Italic on font position 2 (see \(sc2.2).
168: In addition to \fBft\fR and \fB\ef\fIF\fR,
169: the underline font may be selected by \fBul\fR and \fBcu\fR.
170: Underlining is restricted to an output-device-dependent
171: subset of \fIreasonable\fR characters.
172: .h1
173: .bt
174: \fB&ul\fI|N\fR off \fIN\(eq\fR1 E \
175: Underline in \*(NR (italicize in \*(TR) the next \fIN\fR
176: input text lines.
177: Actually, switch to \fIunderline\fR font, saving the
178: current font for later restoration;
179: \fIother\fR font changes within the span of a \fBul\fR
180: will take effect,
181: but the restoration will undo the last change.
182: Output generated by \fBtl\fR (\(sc14) \fIis\fR affected by the
183: font change, but does \fInot\fR decrement \fIN\fR.
184: If \fIN\fR\^>\^1, there is the risk that
185: a trap interpolated macro may provide text
186: lines within the span;
187: environment switching can prevent this.
188: .bt
189: \fB&cu\fI|N\fR off \fIN\(eq\fR1 E \
190: A variant of \fBul\fR that causes \fIevery\fR character to be underlined in \*(NR.
191: Identical to \fBul\fR in \*(TR.
192: .bt
193: \fB&uf\fI|F\fR Italic Italic - \
194: Underline font set to \fIF\fR.
195: In \*(NR,
196: \fIF\fR may \fInot\fR be on position 1 (initially Times Roman).
197: .sc
198: Control characters.
199: Both the control character \fB.\fR and the \fIno-break\fR
200: control character \fB\'\fR may be changed, if desired.
201: Such a change must be compatible with the design
202: of any macros used in the span of the change,
203: and
204: particularly of any trap-invoked macros.
205: .h1
206: .bt
207: \fB&cc\fI|c\fR \fB.\fR \fB.\fR E \
208: The basic control character is set to \fIc\fR,
209: or reset to "\fB.\fR".
210: .bt
211: \fB&c2\fI|c\fR \fB\' \'\fR E The \fInobreak\fR control character is set
212: to \fIc\fR, or reset to "\fB\'\fR".
213: .sc
214: Output translation.
215: One character can be made a stand-in for another character using \fBtr\fR.
216: All text processing (e. g. character comparisons) takes place
217: with the input (stand-in) character which appears to have the width of the final
218: character.
219: The graphic translation occurs at the moment of output
220: (including diversion).
221: .h1
222: .bt
223: \fB&tr\fI|abcd....\fR none - O Translate \
224: \fIa\fR into \fIb\fR, \fIc\fR into \fId\fR, etc.
225: If an odd number of characters is given,
226: the last one will be mapped into the space character.
227: To be consistent, a particular translation
228: must stay in effect from \fIinput\fR to \fIoutput\fR time.
229: .sc
230: Transparent throughput.
231: An input line beginning with a \fB\e!\fR is read in \fIcopy mode\fR and \fItransparently\fR output
232: (without the initial \fB\e!\fR);
233: the text processor is otherwise unaware of the line's presence.
234: This mechanism may be used to pass control information to a post-processor
235: or to imbed control lines in a macro created by a diversion.
236: .sc
237: Comments and concealed newlines.
238: An uncomfortably long input line that must stay
239: one line (e. g. a string definition, or nofilled text)
240: can be split into many physical lines by ending all but
241: the last one with the escape \fB\e\fR.
242: The sequence \fB\e\fR(newline) is \fIalways\fR ignored\(em\
243: except in a comment.
244: Comments may be imbedded at the \fIend\fR of any line by
245: prefacing them with \fB\e"\fR.
246: The newline at the end of a comment cannot be concealed.
247: A line beginning with \fB\e"\fR will appear as a blank line and
248: behave like \fB.sp|1\fR;
249: a comment can be on a line by itself by beginning the line with \fB.\e"\fR.
250: .mh
251: Local Horizontal and Vertical Motions, and the Width Function
252: .sc
253: Local Motions.
254: The functions \fB\ev\'\fIN\fB\|\'\fR and
255: \fB\eh\'\fIN\fB\|\'\fR
256: can be used for \fIlocal\fR vertical and horizontal motion respectively.
257: The distance \fIN\fR may be negative; the \fIpositive\fR directions
258: are \fIrightward\fR and \fIdownward\fR.
259: A \fIlocal\fR motion is one contained \fIwithin\fR a line.
260: To avoid unexpected vertical dislocations, it is necessary that
261: the \fInet\fR vertical local motion within a word in filled text
262: and otherwise within a line balance to zero.
263: The above and certain other escape sequences providing local motion are
264: summarized in the following table.
265: .tr ||
266: .ds X \0\0\0
267: .TS
268: center box;
269: c2|cs2||c2|cs2
270: c1|c2c2||c2|c2c2.
271: Vertical Effect in Horizontal Effect in
272: Local Motion \*(TR \*(NR Local Motion \*(TR \*(NR
273: _
274: .sp.4
275: .TC
276: l2|ls2||l2|ls2.
277: \fB\*X\ev\'\fIN\|\^\fB\'\fR Move distance \fIN\fR \
278: \fB\*X\eh\'\fIN\|\^\fB\'\fR Move distance \fIN\fR
279: .TC
280: _2|_2_2||l2|ls2.
281: \fB\*X\e\fR(space) Unpaddable space-size space
282: .TC
283: l2|l2|l2||l2|ls2.
284: \fB\*X\eu\fR \(12 em up \(12 line up \fB\*X\e0\fR Digit-size space
285: .TC
286: l2|l2|l2||_2|_2_2.
287: \fB\*X\ed\fR \(12 em down \(12 line down
288: .TC
289: l2|l2|l2||l2|l2|l2.
290: \fB\*X\er\fR 1 em up 1 line up \fB\*X\e\||\fR 1\(sl6 em space ignored
291: \fB\*X\e^\fR 1\(sl12 em space ignored
292: .sp.4
293: .TE
294: .rm X
295: .tr |
296: As an example,
297: \fBE\s-2\v'-.4m'2\v'.4m'\s+2\fR
298: could be generated by the sequence
299: \fBE\es\-2\ev\'\-0.4m\'2\ev\'0.4m\'\es+2\fR;
300: it should be noted in this example that
301: the 0.4|em vertical motions are at the smaller size.
302: .sc
303: Width Function.
304: The \fIwidth\fR function \fB\ew\'\fIstring\fB\|\'\fR
305: generates the numerical width of \fIstring\fR (in basic units).
306: Size and font changes may be safely imbedded in \fIstring\fR,
307: and will not affect the current environment.
308: For example,
309: \&\fB.ti|\-\\w\'1.|\'u\fR could be used to
310: temporarily indent leftward a distance equal to the
311: size of the string "\fB1.|\fR".
312: .pg
313: The width function also sets three number registers.
314: The registers \fBst\fR and \fBsb\fR are set respectively to the highest and
315: lowest extent of \fIstring\fR relative to the baseline;
316: then, for example,
317: the total \fIheight\fR of the string is \fB\en(stu\-\en(sbu\fR.
318: In \*(TR the number register \fBct\fR is set to a value
319: between 0|and|3:
320: 0 means that all of the characters in \fIstring\fR were short lower
321: case characters without descenders (like \fBe\fR);
322: 1 means that at least one character has a descender (like \fBy\fR);
323: 2 means that at least one character is tall (like \fBH\fR);
324: and 3 means that both tall characters and characters with
325: descenders are present.
326: .sc
327: Mark horizontal place.
328: The escape sequence \fB\ek\fIx\fR will cause the \fIcurrent\fR horizontal
329: position in the \fIinput line\fR to be stored in register \fIx\fR.
330: As an example,
331: the construction \fB\ekx\fIword\|\fB\eh\'\|~\|\enxu+2u\'\fIword\fB\fR
332: will embolden \fIword\fR by backing up to almost its beginning and overprinting it,
333: resulting in \kz\fIword\fR\h'|\nzu+2u'\fIword\fR.
334: .mh
335: Overstrike, Bracket, Line-drawing, and Zero-width Functions
336: .sc
337: Overstriking.
338: Automatically centered overstriking of up to nine characters
339: is provided by the \fIoverstrike\fR function
340: \fB\eo\'\fIstring\fB\|\'\fR.
341: The characters in \fIstring\fR are overprinted with centers aligned; the total width
342: is that of the widest character.
343: \fIstring\fR should \fInot\fR contain local vertical motion.
344: As examples,
345: \fB\eo\'e\e\'\'\fR produces \fB\o'e\''\fR, and
346: \fB\eo\'\e(mo\e(sl\'\fR produces \fB\o'\(mo\(sl'\fR.
347: .sc
348: Zero-width characters.
349: The function \fB\ez\fIc\fR will output \fIc\fR without spacing over
350: it, and can be used to produce left-aligned overstruck
351: combinations.
352: As examples,
353: \fB\ez\e(ci\e(pl\fR will produce \fB\z\(ci\(pl\fR, and
354: \fB\e(br\ez\e(rn\e(ul\e(br\fR will produce the smallest possible
355: constructed box \fB\(br\z\(rn\(ul\(br\fR\|.
356: .sc
357: Large Brackets.
358: The Special Mathematical Font contains a number of bracket construction pieces
359: (\|\|\|\(lt\|\|\|\(lb\|\|\|\(rt\|\|\|\(rb\|\|\|\(lk\|\|\|\(rk\|\|\|\(bv\|\|\|\(lf\|\|\|\(rf\|\|\|\(lc\|\|\|\(rc\|\|)
360: that can be combined into various bracket styles.
361: The function \fB\eb\'\fIstring\fB\|\'\fR may be used to pile
362: up vertically the characters in \fIstring\fR
363: (the first character on top and the last at the bottom);
364: the characters are vertically separated by 1|em and the total
365: pile is centered 1\(sl2\|em above the current baseline
366: (\(12 line in \*(NR).
367: For example,
368: \fB\eb\'\|\e(lc\e(lf\|\'E\e\|~\|\eb\'\|\e(rc\e(rf\|\'\|\ex\'\|\-0.5m\'\|\ex\'0.5m\'\|\fR
369: produces
370: \x'-.5m'\x'.5m'\fB\b'\(lc\(lf'E\|\b'\(rc\(rf'\fR.
371: .sc
372: Line drawing.
373: .tr &&
374: The function \fB\e\|l\|\'\fINc\fB\|\'\fR will draw a string of repeated \fIc\fR\|'s towards the right for a distance \fIN\fR.
375: (\|\fB\el\fR is \fB\e\fR(lower case L).
376: If \fIc\fR looks like a continuation of
377: an expression for \fIN\fR, it may insulated from \fIN\fR with a \fB\e&\fR.
378: If \fIc\fR is not specified, the \fB\(ru\fR (baseline rule) is used
379: (underline character in \*(NR).
380: If \fIN\fR is negative, a backward horizontal motion
381: of size \fIN\fR is made \fIbefore\fR drawing the string.
382: Any space resulting from \fIN\fR\|\(sl(size of \fIc\fR) having a remainder is put at the beginning (left end)
383: of the string.
384: In the case of characters
385: that are designed to be connected such as
386: baseline-rule\ \fB\(ru\fR\|,
387: underrule\ \fB\(ul\fR\|,
388: and
389: root-en\ \fB\(rn\fR\|,
390: the remainder space is covered by over-lapping.
391: If \fIN\fR is \fIless\fR than the width of \fIc\fR,
392: a single \fIc\fR is centered on a distance \fIN\fR.
393: As an example, a macro to underscore a string can be written
394: .br
395: .tr &.
396: .x1
397: .ftB
398: .ne 2.1
399: &de us
400: \e\e$1\e\|l\|\'\|~\|0\e(ul\'
401: &&
402: .ftR
403: .x2
404: .ne2.1
405: .de xu
406: \\$1\l'|0\(ul'
407: ..
408: or one to draw a box around a string
409: .x1
410: .ftB
411: &de bx
412: \e(br\e\|~\|\e\e$1\e\|~\|\e(br\e\|l\|\'\|~\|0\e(rn\'\e\|l\|\'\|~\|0\e(ul\'
413: &&
414: .ftR
415: .x2
416: .de bx
417: \(br\|\\$1\|\(br\l'|0\(rn'\l'|0\(ul'
418: ..
419: such that
420: .x1
421: .ftB
422: &us "underlined words"
423: .ftR
424: .x2
425: and
426: .x1
427: .ftB
428: &bx "words in a box"
429: .ftR
430: .x2
431: yield
432: .xu "underlined words"
433: and
434: .bx "words in a box"
435: \h'-\w'.'u'.
436: .pg
437: The function \fB\eL\'\|\fINc\fB\|\'\fR will draw a vertical line consisting
438: of the (optional) character \fIc\fR stacked vertically apart 1\|em
439: (1 line in \*(NR),
440: with the first two characters overlapped,
441: if necessary, to form a continuous line.
442: The default character is the \fIbox rule\fR |\(br| (\fB\|\e(br\fR);
443: the other suitable character is the \fIbold vertical\fR \|\(bv\| (\fB\|\e(bv\fR).
444: The line is begun without any initial motion relative to the
445: current base line.
446: A positive \fIN\fR specifies a line drawn downward and
447: a negative \fIN\fR specifies a line drawn upward.
448: After the line is drawn \fIno\fR compensating
449: motions are made;
450: the instantaneous baseline is at the \fIend\fR of the line.
451: .pg
452: .de eb
453: .sp -1
454: .nf
455: \h'-.5n'\L'|\\nzu-1'\l'\\n(.lu+1n\(ul'\L'-|\\nzu+1'\l'|0u-.5n\(ul'
456: .fi
457: ..
458: .ne 2i
459: .mk z
460: The horizontal and vertical line drawing functions may be used
461: in combination to produce large boxes.
462: The zero-width \fIbox-rule\fR and the \(12-em wide \fIunderrule\fR
463: were \fIdesigned\fR to form corners when using 1-em vertical
464: spacings.
465: For example the macro
466: .x1
467: .ftB
468: \&.de eb
469: \&.sp \-1 \e"compensate for next automatic base-line spacing
470: \&.nf \e"avoid possibly overflowing word buffer
471: .tr ||
472: \&\eh\'\-.5n\'\eL\'\||\|\e\enau\-1\'\el\'\e\en(.lu+1n\e(ul\'\eL\'\-\||\|\e\enau+1\'\el\'\||\|0u\-.5n\e(ul\' \e"draw box
473: .tr |
474: .lg0
475: \&.fi
476: .lg
477: \&..
478: .ftR
479: .x2
480: will draw a box around some text whose beginning vertical place was
481: saved in number register \fIa\fR
482: (e. g. using \fB.mk|a\fR)
483: as done for this paragraph.
484: .eb
This archive runs on limited infrastructure. Preserving old code on modern bandwidth. Automated agents are requested to crawl responsibly.