/share/doc/usd/21.troff/m3

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  1. .\" Copyright (C) Caldera International Inc. 2001-2002. All rights reserved.
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  3. .\" Redistribution and use in source and binary forms, with or without
  4. .\" modification, are permitted provided that the following conditions are
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  8. .\" copyright notice, this list of conditions and the following
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  12. .\" notice, this list of conditions and the following disclaimer in the
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  36. .\"
  37. .\" @(#)m3 8.1 (Berkeley) 8/14/93
  38. .\"
  39. .\" $FreeBSD$
  40. .tr |
  41. .rm mx
  42. .mh
  43. Tabs, Leaders, and Fields
  44. .sc
  45. Tabs and leaders.
  46. The \s-1ASCII\s+1 horizontal tab character and the \s-1ASCII\s+1
  47. \s-1SOH\s+1 (hereafter known as the \fIleader\fR character)
  48. can both be used to generate either horizontal motion or
  49. a string of repeated characters.
  50. The length of the generated entity is governed
  51. by internal \fItab stops\fR specifiable
  52. with \fBta\fR.
  53. The default difference is that tabs generate motion and leaders generate
  54. a string of periods;
  55. \fBtc\fR and \fBlc\fR
  56. offer the choice of repeated character or motion.
  57. There are three types of internal tab stops\(em\
  58. \fIleft\fR adjusting, \fIright\fR adjusting,
  59. and \fIcentering\fR.
  60. In the following table:
  61. \fID\fR is the distance from the current position on the \fIinput\fR line
  62. (where a tab or leader was found)
  63. to the next tab stop;
  64. \fInext-string\fR consists
  65. of the input characters following the tab (or leader) up to the next tab (or leader) or end of line;
  66. and
  67. \fIW\fR is the width of \fInext-string\fR.
  68. .TS
  69. center box;
  70. c2|c2|c
  71. c2|c2|c
  72. c2|c2|l.
  73. Tab Length of motion or Location of
  74. type repeated characters \fInext-string\fR
  75. _
  76. Left \fID\fR Following \fID\fR
  77. Right \fID\-W\fR Right adjusted within \fID\fR
  78. Centered \fID\-W\(sl\fR2 Centered on right end of \fID\fR
  79. .TE
  80. The length of generated motion is allowed to be negative, but
  81. that of a repeated character string cannot be.
  82. Repeated character strings contain an integer number of characters, and
  83. any residual distance is prepended as motion.
  84. Tabs or leaders found after the last tab stop are ignored, but may be used
  85. as \fInext-string\fR terminators.
  86. .pg
  87. Tabs and leaders are not interpreted in \fIcopy mode\fR.
  88. \fB\et\fR and \fB\ea\fR always generate a non-interpreted
  89. tab and leader respectively, and
  90. are equivalent to actual tabs and leaders in \fIcopy mode\fR.
  91. .sc
  92. Fields.
  93. A \fIfield\fR is contained between
  94. a \fIpair\fR of \fIfield delimiter\fR characters,
  95. and consists of sub-strings
  96. separated by \fIpadding\fR indicator characters.
  97. The field length is the distance on the
  98. \fIinput\fR line from the position where the field begins to the next tab stop.
  99. The difference between the total length of all the sub-strings
  100. and the field length is incorporated as horizontal
  101. padding space that is divided among the indicated
  102. padding places.
  103. The incorporated padding is allowed to be negative.
  104. For example,
  105. if the field delimiter is \fB#\fR and the padding indicator is \fB^\fR,
  106. \fB#^\fIxxx\fB^\fIright\|\fB#\fR
  107. specifies a right-adjusted string with the string \fIxxx\fR centered
  108. in the remaining space.
  109. .h1
  110. .bt
  111. \fB&ta\fI|Nt|...\fR 8n;|0.5in none E,\fBm\fR \
  112. Set tab stops and types.
  113. \fIt=\fBR\fR, right adjusting;
  114. \fIt=\fBC\fR, centering;
  115. \fIt\fR absent, left adjusting.
  116. \*(TR tab stops are preset every 0.5in.;
  117. \*(NR every 8 character widths.
  118. The stop values are separated by spaces, and
  119. a value preceded by \fB+\fR
  120. is treated as an increment to the previous stop value.
  121. .bt
  122. \fB&tc\fI|c\fR none none E \
  123. The tab repetition character becomes \fIc\fR,
  124. or is removed specifying motion.
  125. .bt
  126. \fB&lc\fI|c\fR \fB.\fR none E \
  127. The leader repetition character becomes \fIc\fR,
  128. or is removed specifying motion.
  129. .bt
  130. \fB&fc\fI|a|b\fR off off - \
  131. The field delimiter is set to \fIa\fR;
  132. the padding indicator is set to the \fIspace\fR character or to
  133. \fIb\fR, if given.
  134. In the absence of arguments the field mechanism is turned off.
  135. .mh
  136. Input and Output Conventions and Character Translations
  137. .sc
  138. Input character translations.
  139. Ways of inputting the graphic character set were
  140. discussed in \(sc2.1.
  141. The \s-1ASCII\s+1 control characters horizontal tab (\(sc9.1),
  142. \s-1SOH\s+1 (\(sc9.1), and backspace (\(sc10.3) are discussed elsewhere.
  143. The newline delimits input lines.
  144. In addition,
  145. \s-1STX\s+1, \s-1ETX\s+1, \s-1ENQ\s+1, \s-1ACK\s+1, and \s-1BEL\s+1
  146. are accepted,
  147. and may be used as delimiters or translated into a graphic with \fBtr\fR (\(sc10.5).
  148. \fIAll\fR others are ignored.
  149. .pg
  150. The \fIescape\fR character \fB\e\fR
  151. introduces \fIescape sequences\fR\(em\
  152. causes the following character to mean
  153. another character, or to indicate
  154. some function.
  155. A complete list of such sequences is given in the Summary and Index on page 6.
  156. \fB\e\fR
  157. should not be confused with the \s-1ASCII\s+1 control character \s-1ESC\s+1 of the
  158. same name.
  159. The escape character \fB\e\fR can be input with the sequence \fB\e\e\fR.
  160. The escape character can be changed with \fBec\fR,
  161. and all that has been said about the default \fB\e\fR becomes true
  162. for the new escape character.
  163. \fB\ee\fR can be used to print whatever the current escape character is.
  164. If necessary or convenient, the escape mechanism may be turned off with \fBeo\fR,
  165. and restored with \fBec\fR.
  166. .h1
  167. .bt
  168. \fB&ec\fI|c\fR \fB\e\fR \fB\e\fR - \
  169. Set escape character to \fB\e\fR, or to \fIc\fR, if given.
  170. .bt
  171. \fB&eo\fR on - - Turn escape mechanism off.
  172. .sc
  173. Ligatures.
  174. .lg 0
  175. Five ligatures are available
  176. in the current \*(TR character set \(em
  177. \fB\(fi\fR, \fB\(fl\fR, \fB\(ff\fR, \fB\(Fi\fR, and \fB\(Fl\fR.
  178. They may be input (even in \*(NR) by
  179. \fB\e(fi\fR, \fB\e(fl\fR, \fB\e(ff\fR, \fB\e(Fi\fR, and \fB\e(Fl\fR respectively.
  180. .lg
  181. The ligature mode is normally on in \*(TR, and \fIautomatically\fR invokes
  182. ligatures during input.
  183. .h1
  184. .bt
  185. \fB&lg\fI|N\fR off;|on on - Ligature mode
  186. is turned on if \fIN\fR is absent or non-zero,
  187. and turned off if \fIN\(eq\^\fR0.
  188. If \fIN\fR\(eq\^2, only the two-character ligatures are automatically invoked.
  189. Ligature mode is inhibited for
  190. request, macro, string, register, or file names,
  191. and in \fIcopy mode\fR.
  192. No effect in \*(NR.
  193. .sc
  194. Backspacing, underlining, overstriking, etc.
  195. Unless in \fIcopy mode\fR, the \s-1ASCII\s+1 backspace character is replaced
  196. by a backward horizontal motion having the width of the
  197. space character.
  198. Underlining as a form of line-drawing is discussed in \(sc12.4.
  199. A generalized overstriking function is described in \(sc12.1.
  200. .pg
  201. \*(NR automatically underlines
  202. characters in the \fIunderline\fR font,
  203. specifiable with \fBuf\fR,
  204. normally Times Italic on font position 2 (see \(sc2.2).
  205. In addition to \fBft\fR and \fB\ef\fIF\fR,
  206. the underline font may be selected by \fBul\fR and \fBcu\fR.
  207. Underlining is restricted to an output-device-dependent
  208. subset of \fIreasonable\fR characters.
  209. .h1
  210. .bt
  211. \fB&ul\fI|N\fR off \fIN\(eq\fR1 E \
  212. Underline in \*(NR (italicize in \*(TR) the next \fIN\fR
  213. input text lines.
  214. Actually, switch to \fIunderline\fR font, saving the
  215. current font for later restoration;
  216. \fIother\fR font changes within the span of a \fBul\fR
  217. will take effect,
  218. but the restoration will undo the last change.
  219. Output generated by \fBtl\fR (\(sc14) \fIis\fR affected by the
  220. font change, but does \fInot\fR decrement \fIN\fR.
  221. If \fIN\fR\^>\^1, there is the risk that
  222. a trap interpolated macro may provide text
  223. lines within the span;
  224. environment switching can prevent this.
  225. .bt
  226. \fB&cu\fI|N\fR off \fIN\(eq\fR1 E \
  227. A variant of \fBul\fR that causes \fIevery\fR character to be underlined in \*(NR.
  228. Identical to \fBul\fR in \*(TR.
  229. .bt
  230. \fB&uf\fI|F\fR Italic Italic - \
  231. Underline font set to \fIF\fR.
  232. In \*(NR,
  233. \fIF\fR may \fInot\fR be on position 1 (initially Times Roman).
  234. .sc
  235. Control characters.
  236. Both the control character \fB.\fR and the \fIno-break\fR
  237. control character \fB\'\fR may be changed, if desired.
  238. Such a change must be compatible with the design
  239. of any macros used in the span of the change,
  240. and
  241. particularly of any trap-invoked macros.
  242. .h1
  243. .bt
  244. \fB&cc\fI|c\fR \fB.\fR \fB.\fR E \
  245. The basic control character is set to \fIc\fR,
  246. or reset to "\fB.\fR".
  247. .bt
  248. \fB&c2\fI|c\fR \fB\' \'\fR E The \fInobreak\fR control character is set
  249. to \fIc\fR, or reset to "\fB\'\fR".
  250. .sc
  251. Output translation.
  252. One character can be made a stand-in for another character using \fBtr\fR.
  253. All text processing (e. g. character comparisons) takes place
  254. with the input (stand-in) character which appears to have the width of the final
  255. character.
  256. The graphic translation occurs at the moment of output
  257. (including diversion).
  258. .h1
  259. .bt
  260. \fB&tr\fI|abcd....\fR none - O Translate \
  261. \fIa\fR into \fIb\fR, \fIc\fR into \fId\fR, etc.
  262. If an odd number of characters is given,
  263. the last one will be mapped into the space character.
  264. To be consistent, a particular translation
  265. must stay in effect from \fIinput\fR to \fIoutput\fR time.
  266. .sc
  267. Transparent throughput.
  268. An input line beginning with a \fB\e!\fR is read in \fIcopy mode\fR and \fItransparently\fR output
  269. (without the initial \fB\e!\fR);
  270. the text processor is otherwise unaware of the line's presence.
  271. This mechanism may be used to pass control information to a post-processor
  272. or to imbed control lines in a macro created by a diversion.
  273. .sc
  274. Comments and concealed newlines.
  275. An uncomfortably long input line that must stay
  276. one line (e. g. a string definition, or nofilled text)
  277. can be split into many physical lines by ending all but
  278. the last one with the escape \fB\e\fR.
  279. The sequence \fB\e\fR(newline) is \fIalways\fR ignored\(em\
  280. except in a comment.
  281. Comments may be imbedded at the \fIend\fR of any line by
  282. prefacing them with \fB\e"\fR.
  283. The newline at the end of a comment cannot be concealed.
  284. A line beginning with \fB\e"\fR will appear as a blank line and
  285. behave like \fB.sp|1\fR;
  286. a comment can be on a line by itself by beginning the line with \fB.\e"\fR.
  287. .mh
  288. Local Horizontal and Vertical Motions, and the Width Function
  289. .sc
  290. Local Motions.
  291. The functions \fB\ev\'\fIN\fB\|\'\fR and
  292. \fB\eh\'\fIN\fB\|\'\fR
  293. can be used for \fIlocal\fR vertical and horizontal motion respectively.
  294. The distance \fIN\fR may be negative; the \fIpositive\fR directions
  295. are \fIrightward\fR and \fIdownward\fR.
  296. A \fIlocal\fR motion is one contained \fIwithin\fR a line.
  297. To avoid unexpected vertical dislocations, it is necessary that
  298. the \fInet\fR vertical local motion within a word in filled text
  299. and otherwise within a line balance to zero.
  300. The above and certain other escape sequences providing local motion are
  301. summarized in the following table.
  302. .tr ||
  303. .ds X \0\0\0
  304. .TS
  305. center box;
  306. c2|cs2||c2|cs
  307. c1|c2c2||c2|c2c.
  308. Vertical Effect in Horizontal Effect in
  309. Local Motion \*(TR \*(NR Local Motion \*(TR \*(NR
  310. _
  311. .sp .4
  312. .T&
  313. l2|ls2||l2|ls.
  314. \fB\*X\ev\'\fIN\|\^\fB\'\fR Move distance \fIN\fR \
  315. \fB\*X\eh\'\fIN\|\^\fB\'\fR Move distance \fIN\fR
  316. .T&
  317. _2|_2_2||l2|ls.
  318. \fB\*X\e\fR(space) Unpaddable space-size space
  319. .T&
  320. l2|l2|l2||l2|ls.
  321. \fB\*X\eu\fR \(12 em up \(12 line up \fB\*X\e0\fR Digit-size space
  322. .T&
  323. l2|l2|l2||_2|_2_.
  324. \fB\*X\ed\fR \(12 em down \(12 line down
  325. .T&
  326. l2|l2|l2||l2|l2|l.
  327. \fB\*X\er\fR 1 em up 1 line up \fB\*X\e\||\fR 1\(sl6 em space ignored
  328. \fB\*X\e^\fR 1\(sl12 em space ignored
  329. .sp .4
  330. .TE
  331. .rm X
  332. .tr |
  333. As an example,
  334. \fBE\s-2\v'-.4m'2\v'.4m'\s+2\fR
  335. could be generated by the sequence
  336. \fBE\es\-2\ev\'\-0.4m\'2\ev\'0.4m\'\es+2\fR;
  337. it should be noted in this example that
  338. the 0.4|em vertical motions are at the smaller size.
  339. .sc
  340. Width Function.
  341. The \fIwidth\fR function \fB\ew\'\fIstring\fB\|\'\fR
  342. generates the numerical width of \fIstring\fR (in basic units).
  343. Size and font changes may be safely imbedded in \fIstring\fR,
  344. and will not affect the current environment.
  345. For example,
  346. \&\fB.ti|\-\\w\'1.|\'u\fR could be used to
  347. temporarily indent leftward a distance equal to the
  348. size of the string "\fB1.|\fR".
  349. .pg
  350. The width function also sets three number registers.
  351. The registers \fBst\fR and \fBsb\fR are set respectively to the highest and
  352. lowest extent of \fIstring\fR relative to the baseline;
  353. then, for example,
  354. the total \fIheight\fR of the string is \fB\en(stu\-\en(sbu\fR.
  355. In \*(TR the number register \fBct\fR is set to a value
  356. between 0|and|3:
  357. 0 means that all of the characters in \fIstring\fR were short lower
  358. case characters without descenders (like \fBe\fR);
  359. 1 means that at least one character has a descender (like \fBy\fR);
  360. 2 means that at least one character is tall (like \fBH\fR);
  361. and 3 means that both tall characters and characters with
  362. descenders are present.
  363. .sc
  364. Mark horizontal place.
  365. The escape sequence \fB\ek\fIx\fR will cause the \fIcurrent\fR horizontal
  366. position in the \fIinput line\fR to be stored in register \fIx\fR.
  367. As an example,
  368. the construction \fB\ekx\fIword\|\fB\eh\'\|~\|\enxu+2u\'\fIword\fB\fR
  369. will embolden \fIword\fR by backing up to almost its beginning and overprinting it,
  370. resulting in \kz\fIword\fR\h'|\nzu+2u'\fIword\fR.
  371. .mh
  372. Overstrike, Bracket, Line-drawing, and Zero-width Functions
  373. .sc
  374. Overstriking.
  375. Automatically centered overstriking of up to nine characters
  376. is provided by the \fIoverstrike\fR function
  377. \fB\eo\'\fIstring\fB\|\'\fR.
  378. The characters in \fIstring\fR are overprinted with centers aligned; the total width
  379. is that of the widest character.
  380. \fIstring\fR should \fInot\fR contain local vertical motion.
  381. As examples,
  382. \fB\eo\'e\e\'\'\fR produces \fB\o'e\''\fR, and
  383. \fB\eo\'\e(mo\e(sl\'\fR produces \fB\o'\(mo\(sl'\fR.
  384. .sc
  385. Zero-width characters.
  386. The function \fB\ez\fIc\fR will output \fIc\fR without spacing over
  387. it, and can be used to produce left-aligned overstruck
  388. combinations.
  389. As examples,
  390. \fB\ez\e(ci\e(pl\fR will produce \fB\z\(ci\(pl\fR, and
  391. \fB\e(br\ez\e(rn\e(ul\e(br\fR will produce the smallest possible
  392. constructed box \fB\(br\z\(rn\(ul\(br\fR\|.
  393. .sc
  394. Large Brackets.
  395. The Special Mathematical Font contains a number of bracket construction pieces
  396. (\|\|\|\(lt\|\|\|\(lb\|\|\|\(rt\|\|\|\(rb\|\|\|\(lk\|\|\|\(rk\|\|\|\(bv\|\|\|\(lf\|\|\|\(rf\|\|\|\(lc\|\|\|\(rc\|\|)
  397. that can be combined into various bracket styles.
  398. The function \fB\eb\'\fIstring\fB\|\'\fR may be used to pile
  399. up vertically the characters in \fIstring\fR
  400. (the first character on top and the last at the bottom);
  401. the characters are vertically separated by 1|em and the total
  402. pile is centered 1\(sl2\|em above the current baseline
  403. (\(12 line in \*(NR).
  404. For example,
  405. \fB\eb\'\|\e(lc\e(lf\|\'E\e\|~\|\eb\'\|\e(rc\e(rf\|\'\|\ex\'\|\-0.5m\'\|\ex\'0.5m\'\|\fR
  406. produces
  407. \x'-.5m'\x'.5m'\fB\b'\(lc\(lf'E\|\b'\(rc\(rf'\fR.
  408. .sc
  409. Line drawing.
  410. .tr &&
  411. 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.
  412. (\|\fB\el\fR is \fB\e\fR(lower case L).
  413. If \fIc\fR looks like a continuation of
  414. an expression for \fIN\fR, it may insulated from \fIN\fR with a \fB\e&\fR.
  415. If \fIc\fR is not specified, the \fB\(ru\fR (baseline rule) is used
  416. (underline character in \*(NR).
  417. If \fIN\fR is negative, a backward horizontal motion
  418. of size \fIN\fR is made \fIbefore\fR drawing the string.
  419. Any space resulting from \fIN\fR\|\(sl(size of \fIc\fR) having a remainder is put at the beginning (left end)
  420. of the string.
  421. In the case of characters
  422. that are designed to be connected such as
  423. baseline-rule\ \fB\(ru\fR\|,
  424. underrule\ \fB\(ul\fR\|,
  425. and
  426. root-en\ \fB\(rn\fR\|,
  427. the remainder space is covered by over-lapping.
  428. If \fIN\fR is \fIless\fR than the width of \fIc\fR,
  429. a single \fIc\fR is centered on a distance \fIN\fR.
  430. As an example, a macro to underscore a string can be written
  431. .br
  432. .tr &.
  433. .x1
  434. .ft B
  435. .ne 2.1
  436. &de us
  437. \e\e$1\e\|l\|\'\|~\|0\e(ul\'
  438. &&
  439. .ft R
  440. .x2
  441. .ne 2.1
  442. .de xu
  443. \\$1\l'|0\(ul'
  444. ..
  445. or one to draw a box around a string
  446. .x1
  447. .ft B
  448. &de bx
  449. \e(br\e\|~\|\e\e$1\e\|~\|\e(br\e\|l\|\'\|~\|0\e(rn\'\e\|l\|\'\|~\|0\e(ul\'
  450. &&
  451. .ft R
  452. .x2
  453. .de bx
  454. \(br\|\\$1\|\(br\l'|0\(rn'\l'|0\(ul'
  455. ..
  456. such that
  457. .x1
  458. .ft B
  459. &us "underlined words"
  460. .ft R
  461. .x2
  462. and
  463. .x1
  464. .ft B
  465. &bx "words in a box"
  466. .ft R
  467. .x2
  468. yield
  469. .xu "underlined words"
  470. and
  471. .bx "words in a box"
  472. \h'-\w'.'u'.
  473. .pg
  474. The function \fB\eL\'\|\fINc\fB\|\'\fR will draw a vertical line consisting
  475. of the (optional) character \fIc\fR stacked vertically apart 1\|em
  476. (1 line in \*(NR),
  477. with the first two characters overlapped,
  478. if necessary, to form a continuous line.
  479. The default character is the \fIbox rule\fR |\(br| (\fB\|\e(br\fR);
  480. the other suitable character is the \fIbold vertical\fR \|\(bv\| (\fB\|\e(bv\fR).
  481. The line is begun without any initial motion relative to the
  482. current base line.
  483. A positive \fIN\fR specifies a line drawn downward and
  484. a negative \fIN\fR specifies a line drawn upward.
  485. After the line is drawn \fIno\fR compensating
  486. motions are made;
  487. the instantaneous baseline is at the \fIend\fR of the line.
  488. .pg
  489. .de eb
  490. .sp -1
  491. .nf
  492. \h'-.5n'\L'|\\nzu-1'\l'\\n(.lu+1n\(ul'\L'-|\\nzu+1'\l'|0u-.5n\(ul'
  493. .fi
  494. ..
  495. .ne 2i
  496. .mk z
  497. The horizontal and vertical line drawing functions may be used
  498. in combination to produce large boxes.
  499. The zero-width \fIbox-rule\fR and the \(12-em wide \fIunderrule\fR
  500. were \fIdesigned\fR to form corners when using 1-em vertical
  501. spacings.
  502. For example the macro
  503. .x1
  504. .ft B
  505. \&.de eb
  506. \&.sp \-1 \e"compensate for next automatic base-line spacing
  507. \&.nf \e"avoid possibly overflowing word buffer
  508. .tr ||
  509. \&\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
  510. .tr |
  511. .lg 0
  512. \&.fi
  513. .lg
  514. \&..
  515. .ft R
  516. .x2
  517. will draw a box around some text whose beginning vertical place was
  518. saved in number register \fIa\fR
  519. (e. g. using \fB.mk|a\fR)
  520. as done for this paragraph.
  521. .eb