You can use either nroff or troff to process files formatted with the standard macro packages, mm, ms, me, and man.

Both nroff and troff expect to find a pointer to the appropriate macro package in the /usr/lib/tmac directory and to find the macro file in the /usr/lib./macro directory.

Printing Files Formatted with mm

Files that use the mm macros can be printed by using nroff or troff, or by using either of two commands developed specifically for the mm macros. These are mm (which nroffs your file) and mmt (which troffs your file).

Using the nroff or troff Command

When you use nroff or troff to print files formatted with mm, your command line takes this form:

nroff -mm options filenames

troff -mm options filenames

The options must precede the filename(s).

A complete listing of nroff and troff options can be found in Table 29.1.

mm uses number registers to keep track of indents, list item numbers and letters, and a host of information related to page layout (page offset, line length, paragraph style, and so forth).

The -r option to nroff/troff lets you set certain number registers on the command line. This initializes the registers because it is done before the macro package is called. Only registers with one-character names can be initialized this way.

Table 29.2 lists the registers that can be initialized with the -r option to nroff/troff.

Table 29.2. Registers That Can Be Initialized on the nroff/troff Command Line

Register

Effect

The -r option is useful if you have a file that will be printed somewhat differently over the course of its life. As an example, assume the first draft of your document has to be double spaced and have the word "DRAFT" at the bottom of every page. Set the C register to 4 on your command line:

troff -mm -rC4 docname

As the document nears completion, you have to print it single spaced, but you still want the word "DRAFT" at the bottom of every page:

troff -mm -rC3 docname

When the document is complete, you can use -rC1 to print "OFFICIAL FILE COPY" at the bottom of each page, or you can use -rC0 to omit that line entirely.

Using the mm or mmt Command

The mm macros are the macros of choice throughout much of AT&T. This may explain why mm has been singled out for special treatment. Only mm has its own set of processing commands: mm, to process files with nroff, and mmt, to process files with troff.

To format a file with mm or mmt, use a command of this form:

mm options filenames

mmt options filenames

As is the case with the nroff and troff commands, the options must precede the filename(s).

The mm and mmt commands have their own set of options; however, they can pass arguments to nroff and troff, so you can use any nroff/troff option as an option to mm/mmt.

mm and mmt can initialize the number registers that can be initialized by the nroff and troff commands. (See Table 29.2.)

Using with ms, me, and man

You can use either nroff or troff to process files that use the me, ms, or man macros. All of the options shown in Table 29.1 can be used; however, the -r option has limited use because all predefined number registers in me and ms have two-character names.

Most of man's predefined number registers also have two-character names. You can set register s to 1 to reduce the page size from 8 1/2 by 11 to 5 1/2 by 8.

Printing Files Formatted with Your Own Macro Package

To substitute your own macro package for mm, ms, me, or man, you have a choice of two methods:

• Use nroff or troff without the -m option and source in your own macro file at the top of your text file (right after you initialize registers).
  
  
• Use the -m option to nroff or troff and specify your macro file. Remember to specify the full pathname.
  
  

All other options to nroff and troff can be used just as you use them for mm, ms, me, or man. Remember that the -r option can be used only to initialize registers with one-character names.

Error Messages

Error messages are largely self explanatory. They can be generated by the system (if you type torff instead of troff), by nroff or troff, by the macro package, or by the preprocessors. (Chapter 23, Formatting Tables with tbl," Chapter 24, "Formatting Equations with eqn," Chapter 25, "Drawing Pictures with pic," and Chapter 26, "Creating Graphs with grap" contain information about error messages generated by the proprocessors.

It doesn't really matter whether troff or mm generates a message; you have to correct the error. Errors usually fall into one of the following categories:

• Order: Memo type macros for mm or ms are in the wrong order.
  
  
• Missing one of bracketed pair: You have a .TS but no .TE (or vice versa).
  
  
• (mm only) No list active: You have a .LI, but no .BL.
  
  
• Bad or no argument: You've omitted an argument after a .VL or you've specified an impossible number as an argument (5 for .SA, for example).
  
  

The one thing to remember is that the line number, helpfully supplied by troff, is the troff output line number. So it's not uncommon to be told that you have an error in line 1500 when your text file is 600 lines long. mm attempts to give you the source file line number. Don't wager a large amount on its accuracy.

Deroffing, or Removing All Traces of nroff/troff

Sometimes documentation customers want electronic files as well as hard copy. If they can't handle troff, they may request ASCII files from you. There's a simple way of complying with this request—use deroff.

deroff removes all troff requests, macros, and backslash constructs. It also removes tbl commands (that is, everything between the .TS and the .TE), equation commands (everything between the .EQ and the .EN or between the defined eqn delimiters). It can follow a chain of included files, so if you've sourced in a file with .so or .nx, deroff operates on those files, too. This feature can be suppressed with the -i option, which simply removes the .so and .nx lines from your file.

Other options are -mm and -ml. -mm completely deletes any line that starts with a macro. This means all your headings will be gone. The -ml option invokes -mm and removes all lists.

This may be just as well. deroff doesn't do well with nested lists.

deroff, like nroff and troff, can process multiple files.

To use deroff, enter the following:

$ deroff options inputfilename > outputfilename

Don't forget to redirect the output to a file. You don't really want to see your denuded, deroffed file streaking across your screen, do you?

Summary

man commandname