 | Chapter 12 nroff and troff |  |
nroff/troff initializes the formatting environment. For example, unless you reset the line length, nroff/troff uses 6.5 inches. Most requests can change the default environment, and those that can are listed in Table 12.1. The second column lists the initial or default value in effect before the request is used. If no initial value applies, a hyphen (-) is used. The third column shows the effect if a request's optional argument is not used. Here, a hyphen is used if the request doesn't accept an argument or if the argument is required.
| Request | Initial Value | If No Argument | Description |
|---|---|---|---|
.ad | Justify | Justify | Adjust margins. |
.af | Lowercase arabic | - | Assign a format to a register. |
.am | - | End call with .. | Append to a macro. |
.bd | Off | - | Embolden font. |
.c2 | ' | ' | Set no-break control character. |
.cc | . | . | Set control character. |
.ce | Off | Center one line | Center lines. |
.ch | - | Turn off trap | Change trap position. |
.cs | Off | - | Set constant-width spacing. |
.cu | Off | One line | Continuous underline/italicize. |
.da | - | End the diversion | Divert text and append to a macro. |
.de | - | End macro with .. | Define a macro. |
.di | - | End the diversion | Divert text to a macro. |
.dt | - | Turn off trap | Set a diversion trap. |
.ec | \ | \ | Set escape character. |
.eo | On | - | Turn off escape character. |
.ev | 0 | Previous environment | Change environment (push down). |
.fc | Off | Off | Set field delimiter and pad character. |
.fi | Fill | - | Fill lines. |
.fp | 1=R | - | Mount font (on positions 1-4). |
| 2=I | |||
| 3=B | |||
| 4=S | |||
.ft | Roman | Previous font | Set font. |
.hc | \% | \% | Set hyphenation character. |
.hy | Mode 1 | Mode 1 | Set hyphenation mode. |
.ig | - | End with .. | Suppress (ignore) text in output. |
.in | 0 | Previous indent | Indent. |
.it | - | Turn off trap | Set a trap for input line counting. |
.lc | . | None | Set leader character. |
.lg | Off (nroff) | On | Ligature mode. |
| On (troff) | |||
.ll | 6.5 inches | Previous line length | Set line length. |
.ls | Single-space | Previous mode | Set line spacing. |
.lt | 6.5 inches | Previous title length | Set length of title. |
.mc | - | Turn off | Set the margin character. |
.mk | - | Internal | Mark vertical position. |
.na | Adjust | - | Don't adjust margins. |
.ne | - | One vertical line | Keep lines on same page if there's room. |
.nf | Fill | - | Don't fill lines. |
.nh | On | - | Turn off hyphenation. |
.nm | Off | Off | Line-numbering mode. |
.nn | - | One line | Don't number next N lines. |
.ns | Space mode | - | Enable no-space mode. |
.nx | - | End of file | Go to a file. |
.pc | % | Off | Set page character. |
.pl | 11 inches | 11 inches | Set page length. |
.pn | Page 1 | - | Set page number. |
.po | 0 (nroff); 26/27 inch (otroff) | Previous offset | Change page offset. |
| 1 inch (ditroff) | |||
.ps | 10 | Previous point size | Set point size. |
.rd | - | Ring bell | Read from the terminal. |
.rt | - | Internal | Return to marked vertical place. |
.sp | - | One vertical line | Output blank spacing. |
.ss | 12/36 em | Ignored | Set character spacing. |
.sv | - | One vertical line | Save (store) spacing. |
.ta | 8 en (nroff); 1/2 inch (troff) | - | Define tab settings. |
.tc | - | - | Set tab repetition character. |
.ti | 0 | - | Indent next line. |
.tm | - | Newline | Print a message, then continue. |
.tr | - | - | Translate pairs of characters on output. |
.uf | Italic | Italic | Set font for underlining. |
.ul | 0 | One line | Underline/italicize. |
.vs | 1/6 inch (nroff); 12 points (troff) | Previous value | Set vertical spacing for lines. |
Comments in nroff/troff begin with \". Lines beginning with . that contain an unknown request are ignored. In general, don't put leading whitespace on your text lines. This causes a break, and nroff and troff honors the leading whitespace literally.
Note: the canonical reference for nroff/troff is Bell Labs Computing Science Technical Report #54, Troff User's Manual, by J.F. Ossanna and B.W. Kernighan. It is available in PostScript from http://cm.bell-labs.com/cm/cs/cstr/54.ps.gz. You should read it if you plan to do any serious work in nroff/troff (such as writing or modifying macro packages). This document explains the ideas of diversions, environments, fields, registers, strings, and traps.
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| 12.3 Conceptual Overview |  | 12.5 Group Summary of Requests |
