Valid questions, to be sure, and mom has answers. (Okay -- I have answers, but I speak for mom.)
The documentation is in html because I still find it the best tool for navigating lengthy manuals. Html, with its anchors and links, came into being precisely so people could do something they'd never been able to with the printed word: instantly track down internal and external references in a document.
To me, it's essential that people reading mom's documentation never have difficulty finding precisely the macro they need for a particular task. Equally, when reading up on a macro, they should never be presented with terms or other macro names for which they cannot instantly find accurate explanations. Short of having written the documentation in TeX for the info browser (and TeX bloat is one of the reasons I prefer to typeset with groff), I can think of no better way to achieve the kind of truly useful documentation I wanted than html.
Another reason for html is that working with mom necessarily involves creating files inside a text editor. I use elvis, a truly fabulous vi clone that does a terrific job of rendering basic (text only) html. I may have written mom, but I still regularly call on her documentation. Elvis, with its html capabilities, lets me write and format mom documents AND peruse her documentation, clicking on links as necessary, without ever leaving the comfy confines of my text editor.
Not everyone, of course, uses an editor with html capabilities. For them, firing up a browser is obviously necessary for reading mom's documentation. Browsers being what they are, and not everyone on the globe having the cash for muscle machines to run Galeon, or Konqueror or Mozilla, their browser needs to be fast and light--and probably "text-only".
Some mom users may notice the absence of graphics,
frames, and (for the most part) tables in this documentation. The
reason is simple: text-only browsers. People who, for whatever
reason (choice or necessity), use lynx, or links or w3m to read
the documentation must be able to make sense of it. All of it.
Graphical examples of mom in action might have made
some parts of the documentation easier to write, but would have
excluded text-only browser users. And it goes without saying that
the documentation looks fine if you're reading it in a graphical
browser.
Groff comes with a small library of PostScript
families
(see the
FAMILY
macro for a list). The families have four
fonts
associated with them. These fonts are a combination of
weight
and
shape:
If you do a lot of document processing or typesetting with mom, you'll find, sooner or later, that these families and their associated fonts aren't sufficient. You'll want to supplement them, either with more fonts for the families already provided--"Damn! I need Helvetica Bold Condensed Italic!"--or with entire new families.
Without going into the gory details (yet), while it's true that adding fonts to groff is a relatively straightforward process, extending existing families or adding new ones requires some planning.
The traditional approach to extending groff families has been to create new families for non-default weights and shapes (e.g. Light, which is a weight; Condensed, which is a shape), then to associate them with groff's predefined R, I, B and BI font styles. An example of this can be seen in the groff PostScript font library itself (<prefix>/font/devps/): there's one "family" for Helvetica (HR, HI, HB, HBI) and another for Helvetica Narrow (HNR, HNI, HNB, HNBI).
The difficulty with this approach is that typographers tend to think of "families" as referring to the entire set of font weights and shapes associated with a particular family name. For example, when a typesetter says "the Helvetica family", s/he is including the weights Helvetica Thin, Helvetic Light, Helvetica Regular, Helvetica Bold, Helvetica Heavy, etc, and all their associated shapes (Roman, Italic, Condensed, Narrow, Extended, Outline, etc).
Thus, intuitively, when a typesetter gives mom a .FAM(ILY) directive, s/he reasonably expects that any subsequent .FT directive will access the desired font from the Helvetica family--without the need to state explicitly both family and font to .FT, as it is explained one can do in the FAMILY and FT sections of these documents.
If one had, say, the fonts, Helvetica Light Roman and Helvetica Light Italic as well as Helvetica Light Condensed Roman and Helvetica Light Condensed Italic, the traditional approach would require two "partial" families: HLR/HLI and HLCDR/HLCDI. Accessing these family/font combos routinely throughout a document would then require changing family (with .FAM(ILY)) and selecting the desired font (with .FT R or .FT I), or passing .FT the lengthy family+fontname (.e.g. .FT HLCDI).
Fortunately, groff provides a mechanism whereby it's possible to extend the basic R, I, B and BI fonts ("styles" in groff-speak) so that one can, in fact, create extensive type families, and access all the fonts in them with .ft (groff) or .FT (mom).
mom uses this mechanism to offer, in addition to groff's default PostScript font styles, the following:
Mom's extensions to groff's basic font styles ============================================= L = Light Roman LI = Light Italic LCD = Light Condensed Roman LCDI = Light Condensed Italic LEX = Light Extended Roman LEXI = Light Extended Italic CD = Medium/Book Condensed Roman CDI = Medium/Book Condensed Italic EX = Medium/Book Extended Roman EXI = Medium/Book Extended Italic DB = DemiBold Roman DBI = DemiBold Italic BCD = Bold Condensed Roman BCDI = Bold Condensed Italic BEX = Bold Extended Roman BEXI = Bold Extended Italic HV = Heavy Roman HVI = Heavy Italic HVCD = Heavy Condensed Roman HVCDI = Heavy Condensed Italic HVEX = Heavy Extended Roman HVEXI = Heavy Extended Italic BL = Black Roman BLI = Black Italic BLCD = Black Condensed Roman BLCDI = Black Condensed Italic BLEX = Black Extended Roman BLEXI = Black Extended Italic UBL = Ultra-Black Roman UBLI = Ultra-Black ItalicThus, with mom, if you've installed, say, some extra Helvetica fonts and named them according to the convention FS (where "F" means family and "S" means font style), once having entered
.FAMILY H or .FAM Hyou can access any of those Helvetica fonts simply by passing the correct argument from the list above to FT.
For example, if you were working in Medium Roman (.FT R) and you needed Medium Condensed Italic for a while (assuming it's installed), you'd just type
.FT CDIto access the Medium Condensed Italic font from the Helvetica family.
Mom's list of font styles doesn't pretend to be exhaustive, but rather tries to cover the basic weight/shape combinations likely to be found in any reasonably complete type family.
The actual extension names are arbitrary and can be used in a flexible manner. For example, if you create a family that has a DemiBold font (DB) but no Bold font (B), you might find it more convenient to give the DemiBold font the extension "B". Equally, if the family has an ExtraBold font, you might find it more convenient to use the extension "HV" (Heavy).
However, you may, at needs, want to add to mom's list of font styles. You can do this by editing the file, om.tmac. Near the top, you'll see lines of the form
.sty \n[.fp] L \" Light Roman .sty \n[.fp] LI \" Light Italic .sty \n[.fp] LCD \" Light Condensed RomanSimply add your new font style by imitating what you see and plugging in your new font style (having, of course, first created the font, correctly named, in groff's PostScript font directory; see How to create a PostScript font for use with groff).
For example, if you already have some fonts from the Univers family installed and have called the family UN, you might decide at some point to add the Bold Outline font (UNBO). In which case, you'd add
.sty \n[.fp] BO \" Bold Outlineto the .sty \n[.fp] <font style> list in om.tmac.
Be careful, though, that any styles you add do not conflict with family names that already exist. "C", for example, conflicts with the Courier family (CR, CI, CB, CI). Were you to create a font style "C", thinking that .FT C would give you access to font style once you'd given a .FAM(ILY) directive, you'd get a nasty surprise: your type would come out in Courier Roman!
VERY IMPORTANT NOTE: mom's font extensions are
not "user-space" controllable via a macro. If you've
been using groff for a long time, and have already rolled your own
solution to adding PostScript families, fonts, weights, shapes, etc. to
groff, you may find that mom's font extensions
conflict with your own scheme. Should that be the case, comment out
the .sty \n[.fp] <font style> lines found near the
top of the om.tmac file.
How to create a PostScript font for use with groff
These instructions aren't meant to cover all possibilities, merely
to present one way of making PostScript families/fonts available to
groff and mom.
GNU/Linux distributions being what they are, directory locations may differ and the presence of some executables can't be guaranteed. I run a Debian system. The instructions reflect that. Users of other distros will have to interpret them according to the way their distro operates.
What you need before you start:
Initial preparation (you only have to do this once):
If you can't find the site-font directory, locate groff's site-tmac directory, and, as root, create site-font in the same directory as the one that holds site-tmac. E.g., if you find site-tmac in /usr/share/groff, create site-font in /usr/share/groff.
ln -s /usr/local/share/groff/1.19.2/font/devps/generate/textmap textmap
ln -s /usr/local/share/groff/1.19.2/font/devps/text.enc text.enc
Q: How do I choose a GROFF_FONTNAME?
A: Start by considering the family to which the font belongs. If you're adding to a family that already exists in groff's <prefix>/font/devps directory, that will be the first part of the font name. (See here for a list of families already installed, along with their groff names.) Add to that name the appropriate weight/style extension, listed here.
For example, if you're adding Helvetica Light Roman, your GROFF_FONTNAME would be HL. If you're adding Helvetica Light Italic, your GROFF_FONTNAME would be HLI.
If you're adding a font not already in groff's PostScript families, first choose a meaningful name for the family to which the font belongs. The name can be anything you like. If, for example, the family is Garamond, you could choose GARAMOND, GARA, GD, or even just plain G as the family name. Then tack on the appropriate style/weight extension. Thus, if you were installing Garamond Bold Condensed Italic and had chosen GD as the family name for Garamond, your GROFF_FONTNAME would be GDBCDI.
In mom, you can then access the Garamond family with .FAM GD, and the Bold Condensed Italic font wth .FT BCDI.
Note: The family name need not be in upper case, and there's no limit to the length of the name. "Garamond", for example, could be the name you give the Garamond family. In fact, you might find it preferable, since a) you wouldn't have to remember how you'd named the family, and b) should you be scanning your site-font directory, something like GaramondBCDI will be more meaningful than, say, GDBCDI.
Written out in full, adding fonts looks like a lot of work. It
isn't. Basically, it's just:
#! /bin/bash
# A script for installing Type1 fonts.
#
# Builds .afm files from .pfb files, generates a groff font from the
# .afm file, makes a symlink in /usr/lib/ghostscript/font/ to the
# .pfb file, and a symlink in site-font to the groff font
# .pfb filename, stripped of .pfb extension
FONT=`basename $1 .pfb`
# Directory holding my personal collection of type1 fonts
FONTDIR="$HOME/Fonts/Type1"
# Directory holding system ghostscript fonts
GS_FONTDIR="/usr/lib/ghostscript/fonts"
# Location of site-font/devps
GROFF_SITE_FONTDIR="/usr/local/share/groff/site-font/devps"
# Personal groff fonts directory
GROFF_FONTS="$HOME/Fonts/Groff"
# Symlinks to textmap and text.enc
TEXTMAP="$FONTDIR/textmap"
TEXTENC="$FONTDIR/text.enc"
if [ ! `pwd` = "$FONTDIR" ] ; then
echo "Changing into $FONTDIR directory.."
cd $FONTDIR
sleep 1
else
sleep 1
fi
echo -n "Groff name for this font: "
read FONTNAME
sleep 1
echo "Getting .afm.."
getafm $FONT.pfb | gsnd - > $FONT.afm
sleep 1
echo "Creating $FONTNAME.."
afmtodit -e $TEXTENC $FONTDIR/$FONT.afm $TEXTMAP $FONTNAME
mv -i $FONTNAME $GROFF_FONTS
sudo ln -s $GROFF_FONTS/$FONTNAME $GROFF_SITE_FONTDIR/$FONTNAME
sleep 1
echo "Linking $FONT in $GS_FONTDIR.."
cd $GS_FONTDIR
sudo ln -s $FONTDIR/$FONT.afm $FONT.afm
sudo ln -s $FONTDIR/$FONT.pfb $FONT.pfb
sleep 1
# This next bit is Debian specific. If you're not running a
# Debian system, replace it with whatever your distro requires
# in order to register Type1 fonts.
if [ !`pidof -x /usr/bin/dfontmgr` ] ; then
echo "I will now run dfontmgr so you can register the font."
exec sudo dfontmgr &
else
echo "You may now register the font with dfontmgr."
fi
Mom, as a complete macro set, had her origins in a "library" of groff routines I wrote over the years to handle various aspects of typesetting and document processing that weren't adequately covered by ms, me, mm, and so on. Typically, I'd use the library to cobble together macro sets for new challenges as they came my way.
If, as Eric Raymond asserts, open source begins with a programmer scratching a personal itch, then mom can truly be called open source, even if, a mere humble set of macros standing on the shoulders of a giant named troff, she isn't programming at all.
As a writer living in a perpetual state of penury, all the computers I've ever owned have been hand-me-downs -- several generations out-of-date and "resource challenged". Disk space has always been an issue, as has processor speed and available RAM. One of the reasons I run GNU/Linux is that it has helped enormously to get the most out of my poor little boxes. (It has been pointed out to me that NetBSD might be an even better choice of operating systems for computers with limited resources.)
In Linux-land, the choice of typesetting systems basically comes down to groff or TeX. Both are wonderful -- monumental achievements if you ask me -- and both have their own particular strengths. However, for people in my financial position (and there are millions of us around the globe, in both developed and developing countries), TeX and groff have one big difference: size. TeX is huge. Even its most ardent supporters agree it suffers from bloat, on top of being complex and unwieldy to manage. Groff is tiny by comparison, occupying minimal disk space and having only a small memory footprint while at the same time being flexible and powerful, typographically speaking. I've run it successfully on a 386 with 8 megs of RAM and a 250 meg hard disk.
However, groff has always had a liability: it's incredibly geeky. Owing to its very long history, it -- and its "power users" -- have remained stuck in a time warp. Most common macro packages still look as they did in those decades when memory was exorbitantly expensive and every byte mattered. Documentation -- not always easy to find -- is written as if all readers are computer whizzes, or at least have a university degree in one of the higher sciences.
By no means a stupid man, nor unfamiliar with the precepts of programming, I've more than once torn my hair out over the terseness and ambiguity of groff's documentation. Making sense of certain primitives has often involved days of testing, interpreting the documentation instead of just using the primitive.
(ADDENDUM to the previous two paragraphs: A tremendous amount of effort has gone into creating a groff manual that can be read with "info," as well as creating truly useful man pages. The info manual is clear and well-written, so my comments are actually out of date. I leave them in for the benefit of groff newbies, who may still find the documents a bit intimidating.)
For some time now, groff users and macro writers have had the option to use "long" names, yet have mostly chosen not to. With long names, it's possible to create macro sets that are humanly readable and easy to interpret, encouraging development and evolution. What's more, the macros themselves need not be terse, intimidating, and easily forgotten 1- or 2-letter commands inserted in the body of a document. They can be sensible and helpful to everyone, groff newbies and old hands alike.
Mom's macro file, om.tmac, uses long names, aliases,
and a host of other groff goodies that have become part of the
whole groff picture under the unflagging guidance of groff's current
maintainer, Werner Lemberg. Nearly every macro, number register and
string is "recognizable" simply by its name. The file is
heavily commented. A consistent, if idiosyncratic, indenting style
is used as well, significantly improving readability. Anyone
wanting to futz around with mom's macros should be
able to do so with a minimum of head scratching.
If you have any questions or comments about mom, suggestions to make, criticisms to offer, or bugs to report, use the groff mailing list at groff@ffii.org (subscription information available here) or contact me, Peter Schaffter, directly at peter@faustus.dyn.ca or ptpi@golden.net.
Please include the word "mom" or "groff" in the Subject: line of any message sent to my personal address, or you risk the wrath of my implacable spam filters. :)
If you want to visit mom's homepage, you'll find it here.