.ig
	ch01.t
	Typed by: Stewart Russell.
	Marked up by: Michael Hobgood
	Proofed on: 1 Oct 2002
..
.so utp.mac
.utp
.Se 1 "From Typewriters to Word Processors"
.page 1
.LP
Before we consider the special tools that the UNIX environment
provides for text processing, we need to think about the
underlying changes in the process of writing that are inevitable
when you begin to use a computer.
.PP
The most important features of a computer program for writers
are the ability to remember what is typed and the ability
to allow incremental changes\c
\(em\c
no more retyping from scratch
each time a draft is revised.
For a writer first encountering
word processing software, no other features even begin to
compare.
The crudest command structure, the most elementary
formatting capabilities, will be forgiven because of the
immense labor savings that take place.
.PP
Writing is basically an iterative process.
It is a rare writer
who dashes out a finished piece; most of us work in circles,
returning again and again to the same piece of prose, adding or
deleting words, phrases, and sentences, changing the order of
thoughts, and elaborating a single sentence into pages of text.
.PP
A writer working on paper periodically needs to clear the
deck\c
\(em\c
to type a clean copy, free of elaboration.
As the writer
reads the new copy, the process of revision continues, a word
here, a sentence there, until the new draft is as obscured
by changes as the first.
As Joyce Carol Oates is said to have
remarked: \(lqNo book is ever finished.
It is abandoned.\(rq
.PP
Word processing first took hold in the office as a tool to help
secretaries prepare perfect letters, memos, and reports.
As
dedicated word processors were replaced with low-cost personal
computers, writers were quick to see the value of this new
tool.
In a civilization obsessed with the written word, it is
no accident that WordStar, a word processing program, was one
of the first best sellers of the personal computer revolution.
.PP
As you learn to write with a word processor, your working style
changes.
Because it is so easy to make revisions, it is much
more forgivable to think with your fingers when you write,
rather than to carefully outline your thoughts beforehand and
polish each sentence as you create it.
.PP
If you do work from an outline, you can enter it first, then
write your first draft by filling in the outline, section by
section.
If you are writing a structured document such
.page 2
as a
technical manual, your outline points become the headings
in your document; if you are writing a free-flowing work,
they can be subsumed gradually in the text as you flesh them
out.
In either case, it is easy to write in small segments
that can be moved as you reorganize your ideas.
.PP
Watching a writer at work on a word processor is very different
from watching a writer at work on a typewriter.
A typewriter
tends to enforce a linear flow\c
\(em\c
you must write a passage and
then go back later to revise it.
On a word processor, revisions
are constant\c
\(em\c
you type a sentence, then go back to change the
sentence above.
Perhaps you write a few words, change your
mind, and back up to take a different tack; or you decide the
paragraph you just wrote would make more sense if you put it
ahead of the one you wrote before, and move it on the spot.
.PP
This is not to say that a written work is created on a word
processor in a single smooth flow; in fact, the writer using
a word processor tends to create many more drafts than a
compatriot who still uses a pen or typewriter.
Instead of three
or four drafts, the writer may produce ten or twenty.
There
is still a certain editorial distance that comes only when
you read a printed copy.
This is especially true when that
printed copy is nicely formatted and letter perfect.
.PP
This brings us to the second major benefit of word-processing
programs: they help the writer with simple formatting of a
document.
For example, a word processor may automatically insert
carriage returns at the end of each line and adjust the space
between words so that all the lines are the same length.
Even
more importantly, the text is automatically readjusted when
you make changes.
There are probably commands for centering,
underlining, and boldfacing text.
.PP
The rough formatting of a document can cover a multitude of
sins.
As you read through your scrawled markup of a preliminary
typewritten draft, it is easy to lose track of the overall
flow of the document.
Not so when you have a clean copy\c
\(em\c
the
flaws of organization and content stand out vividly against
the crisp new sheets of paper.
.PP
However, the added capability to print a clean draft after
each revision also puts an added burden on the writer.
Where
once you had only to worry about content, you may now find
yourself fussing with consistency of margins, headings,
boldface, italics, and all the other formerly superfluous
impedimenta that have now become integral to your task.
.PP
As the writer gets increasingly involved in the formatting of
a document, it becomes essential that the tools help revise
the document's appearance as easily as its content.
Given
these changes imposed by the evolution from typewriters to
word processors, let's take a look at what a word-processing
system needs to offer to the writer.
.Ah "A Workspace"
.LP
One of the most important capabilities of a word processor is
that it provides a space in which you can create documents.
In
one sense, the video display screen on your terminal, which
echoes the characters you type, is analogous to a sheet
of paper.
But the workspace of a word processor is not so
unambiguous as a sheet of paper wound into a typewriter,
that may be added neatly to the stack of completed work when
finished, or torn out and crumpled as a false start.
From
the computer's point of view, your
.page 3
workspace is a block of
memory, called a
.I buffer ,
that is allocated when you begin a
word-processing session.
This buffer is a temporary holding area
for storing your work and is emptied at the end of each session.
.PP
To save your work, you have to write the contents of the
buffer to a file.
A file is a permanent storage area on a disk
(a hard disk or a floppy disk).
After you have saved your work
in a file, you can retrieve it for use in another session.
.PP
When you begin a session editing a document that exists on file,
a copy of the file is made and its contents are read into the
buffer.
You actually work on the copy, making changes to
.I it ,
not the original.
The file is not changed until you save your
changes during or at the end of your work session.
You can
also discard changes made to the buffered copy, keeping the
original file intact, or save multiple versions of a document
in separate files.
.PP
Particularly when working with larger documents, the management
of disk files can become a major effort.
If, like most writers,
you save multiple drafts, it is easy to lose track of which
version of a file is the latest.
.PP
An ideal text-processing environment for serious writers should
provide tools for saving and managing multiple drafts on disk,
not just on paper.
It should allow the writer to
.RS
.Ls B
.Li
work on documents of any length;
.Li
save multiple versions of a file;
.Li
save part of the buffer into a file for later use;
.Li
switch easily between multiple files;
.Li
insert the contents of an existing file into the buffer;
.Li
summarize the differences between two versions of a document.
.Le
.RE
.LP 0
Most word-processing programs for personal computers seem to
work best for short documents such as the letters and memos
that offices churn out by the millions each day.
Although it is
possible to create longer documents, many features that would
help organize a large document such as a book or manual are
missing from these programs.
.PP
However, long before word processors became popular, programmers
were using another class of programs called
.I "text editors" .
Text
editors were designed chiefly for entering computer programs,
not text.
Furthermore, they were designed for use by computer
professionals, not computer novices.
As a result, a text
editor can be more difficult to learn, lacking many on-screen
formatting features available with most word processors.
.PP
Nonetheless, the text editors used in program development
environments can provide much better facilities for managing
large writing projects than their office word processing
counterparts.
Large programs, like large documents, are often
contained in many separate files; furthermore, it is essential
to track the differences between versions of a program.
.PP
UNIX is a pre-eminent program development environment
and, as such, it is also a superb document development
environment.
Although its text editing tools at first may appear
limited in contrast to sophisticated office word processors,
they are in fact considerably more powerful.
.Ah "Tools for Editing"
.page 4
.LP
For many, the ability to retrieve a document from a file and
make multiple revisions painlessly makes it impossible to
write at a typewriter again.
However, before you can get the
benefits of word processing, there is a lot to learn.
.PP
Editing operations are performed by issuing commands.
Each
word-processing system has its own unique set of commands.
At
a minimum, there are commands to
.RS
.Ls B
.Li
move to a particular position in the document;
.Li
insert new text;
.Li
change or replace text;
.Li
delete text;
.Li
copy or move text.
.Le
.RE
.LP 0
To make changes to a document, you must be able to move to
that place in the text where you want to make your edits.
Most
documents are too large to be displayed in their entirety on
a single terminal screen, which generally displays 24 lines of
text.
Usually only a portion of a document is displayed.
This
partial view of your document is sometimes referred to as a
.I window .*
.FS
*Some editors, such as 
.CW emacs ,
can split the terminal screen
into multiple windows.
In addition, many high-powered UNIX
workstations with large bit-mapped screens have their own
windowing software that allows multiple programs to be run
simultaneously in separate windows.
For purposes of this book,
we assume you are using the
.CW vi
editor and an alphanumeric
terminal with only a single window.
.FE
If you are entering new text and reach the bottom line
in the window, the text on the screen automatically scrolls
(rolls up) to reveal an additional line at the bottom.
A
cursor (an underline or block) marks your current position in
the window.
.PP
There are basically two kinds of movement:
.RS
.Ls B
.Li
scrolling new text into the window
.Li
positioning the cursor within the window
.Le
.RE
.LP 0
When you begin a session, the first line of text is the
first line in the window, and the cursor is positioned on
the first character.
Scrolling commands change which lines
are displayed in the window by moving forward or backward
through the document.
Cursor-positioning commands allow you
to move up and down to individual lines, and along lines to
particular characters.
.PP
After you position the cursor, you must issue a command to make
the desired edit.
The command you choose indicates how much text
will be affected: a character, a word,
a line, or a sentence.
.PP
Because the same keyboard is used to enter both text and
commands, there must be some way to distinguish between the
two.
Some word-processing programs assume that you are entering
text unless you specify otherwise; newly entered text either
.page 5
replaces existing text or pushes it over to make room for the
new text.
Commands are entered by pressing special keys on the
keyboard, or by combining a standard key with a special key,
such as the 
.I "control key"
(\c
.I CTRL ).
.PP
Other programs assume that you are issuing commands; you must
enter a command before you can type any text at all.
There are
advantages and disadvantages to each approach.
Starting out in
text mode is more intuitive to those coming from a typewriter,
but may be slower for experienced writers, because all commands
must be entered by special key combinations that are often
hard to reach and slow down typing.
(We'll return to this
topic when we discuss
.CW vi ,
a UNIX text editor).
.PP
Far more significant than the style of command entry is the
range and speed of commands.
For example, though it is heaven
for someone used to a typewriter to be able to delete a word
and type in a replacement, it is even better to be able to
issue a command that will replace every occurrence of that
word in an entire document.
And, after you start making such
global changes, it is essential to have some way to undo them
if you make a mistake.
.PP
A word processor that substitutes ease of learning for ease of
use by having fewer commands will ultimately fail the serious
writer, because the investment of time spent learning complex
commands can easily be repaid when they simplify complex tasks.
.PP
And when you do issue a complex command, it is important that it
works as quickly as possible, so that you aren't left waiting
while the computer grinds away.
The extra seconds add up when
you spend hours or days at the keyboard, and, once having been
given a taste of freedom from drudgery, writers want as much
freedom as they can get.
.PP
Text editors were developed before word processors (in the
rapid evolution of computers).
Many of them were originally
designed for printing terminals, rather than for the CRT-based
terminals used by word processors.
These programs tend to have
commands that work with text on a line-by-line basis.
These
commands are often more obscure than the equivalent office
word-processing commands.
.PP
However, though the commands used by text editors are sometimes
more difficult to learn, they are usually very effective.
(The
commands designed for use with slow paper terminals were
often extraordinarily powerful, to make up for the limited
capabilities of the input and output device).
.PP
There are two basic kinds of text editors,
.I "line editors"
and
.I "screen editors" ,
and both are available in UNIX.
The difference
is simple: line editors display one line at a time, and screen
editors can display approximately 24 lines or a full screen.
.PP
The line editors in UNIX include
.CW ed ,
.CW sed ,
and
.CW ex .
Although these
line editors are obsolete for general-purpose use by writers,
there are applications at which they excel, as we will see in
Chapters 7 and 12.
.PP
The most common screen editor in UNIX is
.CW vi .
Learning 
.CW vi
or
some other suitable editor is the first step in mastering the
UNIX text-processing environment.
Most of your time will be
spent using the editor.
.PP
UNIX screen editors such as
.CW vi
and 
.CW emacs
(another editor
available on many UNIX systems) lack ease-of-learning features
common in many word processors\c
\(em\c
there are no menus and only
primitive on-line help screens, and the commands are often
complex and nonintuitive\c
\(em\c
but they are powerful and fast.
What's
more, UNIX line editors such as
.CW ex
and
.CW sed
give additional
capabilities not found in word processors\c
\(em\c
the
.page 6
ability to write
a script of editing commands that can be applied to multiple
files.
Such editing scripts open new ranges of capability to
the writer.
.Ah "Document Formatting"
.LP
Text editing is wonderful, but the object of the writing
process is to produce a printed document for others to
read.
And a printed document is more than words on paper;
it is an arrangement of text on a page.
For instance, the
elements of a business letter are arranged in a consistent
format, which helps the person reading the letter identify
those elements.
Reports and more complex documents, such as
technical manuals or books, require even greater attention to
formatting.
The format of a document conveys how information is
organized, assisting in the presentation of ideas to a reader.
.PP
Most word-processing programs have built-in formatting
capabilities.
Formatting commands are intermixed with
editing commands, so that you can shape your document on the
screen.
Such formatting commands are simple extensions of those
available to someone working with a typewriter.
For example,
an automatic centering command saves the trouble of manually
counting characters to center a title or other text.
There may
also be such features as automatic pagination and printing of
headers or footers.
.PP
Text editors, by contrast, usually have few formatting
capabilities.
Because they were designed for entering programs,
their formatting capabilities tend to be oriented toward the
formats required by one or more programming languages.
.PP
Even programmers write reports, however.
Especially at AT&T
(where UNIX was developed), there was a great emphasis
on document preparation tools to help the programmers and
scientists of Bell Labs produce research reports, manuals,
and other documents associated with their development work.
.PP
Word processing, with its emphasis on easy-to-use programs with
simple on-screen formatting, was in its infancy.
Computerized
phototypesetting, on the other hand, was already a developed
art.
Until quite recently, it was not possible to represent
on a video screen the variable type styles and sizes used in
typeset documents.
As a result, phototypesetting has long used
a markup system that indicates formatting instructions with
special codes.
These formatting instructions to the computerized
typesetter are often direct descendants of the instructions
that were formerly given to a human typesetter\c
\(em\c
center the
next line, indent five spaces, boldface this heading.
.PP
The text formatter most commonly used with the UNIX system
is called
.CW nroff .
To use it, you must intersperse formatting
instructions (usually one- or two-letter codes preceded by
a period) within your text, then pass the file through the
formatter.
The 
.CW nroff
program interprets the formatting codes
and reformats the document \(lqon the fly\(rq while passing it
on to the printer.
The 
.CW nroff
formatter prepares documents
for printing on line printers, dot-matrix printers, and
letter-quality printers.
Another program called
.CW troff
uses an
extended version of the same markup language used by
.CW nroff ,
but prepares documents for printing on laser printers and
typesetters.
We'll talk more about printing in a moment.
.PP
Although formatting with a markup language may seem to be
a far inferior system to the \(lqwhat you see is what you get\(rq
(\c
.I wysiwyg )
approach of most office word processing programs,
it actually has many advantages.
.page 7
.PP
First, unless you are using a very sophisticated computer,
with very sophisticated software (what has come to be called
an electronic publishing system, rather than a mere word
processor), it is not possible to display everything on
the screen just as it will appear on the printed page.
For
example, the screen may not be able to represent boldfacing or
underlining except with special formatting codes.
WordStar, one
of the grandfathers of word-processing programs for personal
computers, represents underlining by surrounding the word or
words to be underlined with the special control character
\f[CI]^S\fP
(the character generated by holding down the
.I control
key while
typing the letter 
.I S ).
For example, the following title line
would be underlined when the document is printed:
.Ps
^SWord Processing with WordStar^S
.Pe
.LP 0
Is this really superior to the following
.CW nroff
construct?
.Ps
\&.ul
Text Processing with vi and nroff
.Pe
.LP 0
It is perhaps unfair to pick on WordStar, an older
word-processing program, but very few word-processing programs
can complete the illusion that what you see on the screen
is what you will get on paper.
There is usually some mix of
control codes with on-screen formatting.
More to the point,
though, is the fact that most word processors are oriented
toward the production of short documents.
When you get beyond
a letter, memo, or report, you start to understand that there
is more to formatting than meets the eye.
.PP
Although \(lqwhat you see is what you get\(rq is fine for laying
out a single page, it is much harder to enforce consistency
across a large document.
The design of a large document is often
determined before writing is begun, just as a set of plans for a
house are drawn up before anyone starts construction.
The design
is a plan for organizing a document, arranging various parts
so that the same types of material are handled in the same way.
.PP
The parts of a document might be chapters, sections, or
subsections.
For instance, a technical manual is often organized
into chapters and appendices.
Within each chapter,
there might
be numbered sections that are further divided into three or
four levels of subsections.
.PP
Document design seeks to accomplish across the entire document
what is accomplished by the table of contents of a book.
It
presents the structure of a document and helps the reader
locate information.
.PP
Each of the parts must be clearly identified.
The design
specifies how they will look, trying to achieve consistency
throughout the document.
The strategy might specify that
major section headings will be all uppercase, underlined,
with three blank lines above and two below, and secondary
headings will be in uppercase and lowercase, underlined,
with two blank lines above and one below.
.PP
If you have ever tried to format a large document using a word
processor, you have probably found it difficult to enforce
consistency in such formatting details as these.
By contrast, a
markup language\c
\(em\c
especially one like
.CW nroff
that allows you to
define repeated command sequences, or 
.I macros \c
\(em\c
makes it easy:
the style of a heading is defined once, and a code used
to reference it.
For example, a top-level heading might be
specified by the code
.CW \.H1 ,
and a secondary heading by
.CW \.H2 .
.page 8
Even more significantly, if you later decide to change the
design, you simply change the definition of the relevant
design elements.
If you have used a word processor to format
the document as it was written, it is usually a painful task
to go back and change the format.
.PP
Some word-processing programs, such as Microsoft WORD, include
features for defining global document formats, but these
features are not as widespread as they are in markup systems.
.Ah "Printing"
.LP
The formatting capabilities of a word-processing system are
limited by what can be output on a printer.
For example, some
printers cannot backspace and therefore cannot underline.
For
this discussion, we are considering four different classes
of printers: dot matrix, letter quality, phototypesetter,
and laser.
.PP
A 
.I dot-matrix
printer composes characters as a series of
dots.
It is usually suitable for preparing interoffice memos
and obtaining fast printouts of large files.
.	\" Note: an example paragraph of dot matrix output
.	\" is in the original.  Not having access to any fonts
.	\" that make an attempt to duplicate the poor quality,
.	\" I've just typed the paragraph in using the 
.	\" CW font in .nf mode supplied as defaults in .Ps/.Pe macros.
.	\" In the original printed book, the word "sophisticated"
.	\" was mis-spelled as "sophicated". Corrected here.
.	\" -- Michael Hobgood
.Ps
.sp .5v
This paragraph was printed with a dot-matrix printer.  It uses a print
head containing 9 pins, which are adjusted to produce the shape of each
character.  More sophisticated dot-matrix printers have print heads
containing up to 24 pins.  The greater the number of pins, the finer
the dots that are printed, and the more possible it is to fool the eye
into thinking it sees a solid character.  Dot matrix printers are also
capable of printing out graphic displays.
.Pe
.PP
A 
.I letter-quality
printer is more expensive and slower.
Its
printing mechanism operates like a typewriter and achieves a
similar result.
.	\" This paragraph is simulated using large point, CB type.
.	\" -- Michael Hobgood
.Ps
.ft CB
.ps 12
.vs 14
.sp 2p
This paragraph was printed with a letter-
quality printer.  It is essentially a
computer-controlled typewriter and, like a
typewriter, uses a print ball or wheel
containing fully formed characters.
.ps 9
.vs 10
.ft P
.Pe
.LP
A letter-quality printer produces clearer, easier-to-read
copy than a dot-matrix printer.
Letter-quality printers are
generally used in offices for formal correspondence as well
as for the final drafts of proposals and reports.
.PP
Until very recently, documents that needed a higher quality of
printing than that available with letter-quality printers were
sent out for typesetting.
Even if draft copy was word-processed,
the material was often re-entered by the typesetter, although
many typesetting companies can read the files created by
popular word-processing programs and use them as a starting
point for typesetting.
.page 9
.Ps
.ll 4.5i
.fi
.ft R
.sp .5v
This paragraph, like the rest of this book, was phototypeset.
In
phototypesetting, a photographic technique is used to print
characters on film or photographic paper.
There is a wide choice
of type styles, and the characters are much more finely formed
that those produced by a letter-quality printer.
Characters are
produced by an arrangement of tiny dots, much like a dot-matrix
printer\c
\(em\c
but there are over 1000 dots per inch.
.ll \n[UTPLL]u
.nf
.ft P
.Pe
.LP 0
There are several major advantages to typesetting.
The high
resolution allows for the design of aesthetically pleasing
type.
The shape of the characters is much finer.
In addition,
where dot-matrix and letter-quality type is usually constant
width (narrow letters like
.I i
take up the same amount of space
as wide ones like
.I m ),
typesetters use variable-width type,
in which narrow letters take up less space than wide ones.
In
addition, it's possible to mix styles (for example, bold and
italic) and sizes of type on the same page.
.PP
Most typesetting equipment uses a markup language rather than a
.I wysiwyg
approach to specify point sizes, type styles, leading,
and so on.
Until recently, the technology didn't even exist
to represent on a screen the variable-width typefaces that
appear in published books and magazines.
.PP
AT&T, a company with its own extensive internal publishing
operation, developed its own typesetting markup language
and typesetting program\c
\(em\c
a sister to
.CW nroff
called
.CW troff
(\c
.I typesetter-roff ).
Although
.CW troff
extends the capabilities
of
.CW nroff
in significant ways, it is almost totally compatible
with it.
.PP
Until recently, unless you had access to a typesetter, you
didn't have much use for
.CW troff .
The development of low-cost
laser printers that can produce near typeset quality output
at a fraction of the cost has changed all that.
.	\" again, another simulated paragraph.
.	\" here, I just used bold, roman type.
.	\" -- Michael Hobgood
.Ps
.fi
.ft B
.ll 4.5i
.sp 4p
This paragraph was produced on a laser printer.
Laser printers produce
high-resolution characters\c
\(em\c
300 to 500 dots per inch\c
\(em\c
though they are not quite as finely formed as phototypeset
characters.
Laser printers are not only cheaper to purchase
than phototypesetters, they also print on plain paper, just
like Xerox machines, and are therefore much cheaper to 
operate.
However, as is always the case with computers, you need the
proper software to take advantage of improved hardware
capabilities.
.ft P
.nf
.ll \n[UTPLL]u
.Pe
.LP
Word-processing software (particularly that developed for
the Apple Macintosh, which has a high-resolution graphics
screen capable of representing variable type fonts) is
beginning to tap the capabilities of laser printers.
However,
most of the microcomputer-based packages still have many
limitations.
Nonetheless, a markup language such as that
provided by 
.CW troff
still provides the easiest and lowest-cost
access to the world of electronic publishing for many types
of documents.
.PP
The point made previously, that markup languages are preferable
to
.I wysiwyg
systems for large documents, is especially true
when you begin to use variable size fonts, leading, and other
advanced formatting features.
It is easy to lose track of the
overall format of your document and difficult to make overall
changes after your formatted text is in place.
Only the most
expensive electronic publishing systems (most of them based
on advanced UNIX workstations) give you both the capability to
see what you will get on the screen and the ability to define
and easily change overall document formats.
.Ah "Other UNIX Text-Processing Tools"
.page 10
.LP
Document editing and formatting are the most important parts of
text processing, but they are not the whole story.
For instance,
in writing many types of documents, such as technical manuals,
the writer rarely starts from scratch.
Something is already
written, whether it be a first draft written by someone else,
a product specification, or an outdated version of a manual.
It would be useful to get a copy of that material to work with.
If that material was produced with a word processor or has been
entered on another system, UNIX's communications facilities
can transfer the file from the remote system to your own.
.PP
Then you can use a number of custom-made programs to search
through and extract useful information.
Word-processing programs
often store text in files with different internal formats.
UNIX
provides a number of useful analysis and translation tools
that can help decipher files with nonstandard formats.
Other
tools allow you to \(lqcut and paste\(rq portions of a document into
the one you are writing.
.PP
As the document is being written, there are programs to check
spelling, style, and diction.
The reports produced by those
programs can help you see if there is any detectable pattern in
syntax or structure that might make a document more difficult
for the user than it needs to be.
.PP
Although many documents are written once and published or filed,
there is also a large class of documents (manuals in particular)
that are revised again and again.
Documents such as these
require special tools for managing revisions.
UNIX program
development tools such as SCCS (Source Code Control System)
and
.CW diff
can be used by writers to compare past versions with
the current draft and print out reports of the differences,
or generate printed copies with change bars in the margin
marking the differences.
.PP
In addition to all of the individual tools it provides,
UNIX is a particularly fertile environment for writers who
aren't afraid of computers, because it is easy to write command
files, or
.I "shell scripts" ,
that combine individual programs into
more complex tools to meet your specific needs.
For example,
automatic index generation is a complex task that is not handled
by any of the standard UNIX text-processing tools.
We will
show you ways to perform this and other tasks by applying the
tools available in the UNIX environment and a little ingenuity.
.PP
We have two different objectives in this book.
The first
objective is that you learn to use many of the tools available
on most UNIX systems.
The second objective is that you develop
an understanding of how these different tools can work together
in a document preparation system.
We're not just presenting
a UNIX user's manual, but suggesting applications for which
the various programs can be used.
.PP
To take full advantage of the UNIX text-processing environment,
you must do more than just learn a few programs.
For the writer,
the job includes establishing standards and conventions about
how documents will be stored, in what format they should
appear in print, and what kinds of programs are needed to
help this process take place efficiently with the use of a
computer.
Another way of looking at it is that you have to
make certain choices prior to beginning a project.
We want to
encourage you to make your own choices, set your own standards,
and realize the many possibilities that are open to a diligent
and creative person.
.page 11
.PP
In the past, many of the steps in creating a finished book were
out of the hands of the writer.
Proofreaders and copy editors
went over the text for spelling and grammatical errors.
It
was generally the printer who did the typesetting (a service
usually paid by the publisher).
At the print shop, a typesetter
(a person) retyped the text and specified the font sizes and
styles.
A graphic artist, performing layout and pasteup, made
many of the decisions about the appearance of the printed page.
.PP
Although producing a high-quality book can still involve many
people, UNIX provides the tools that allow a writer to control
the process from start to finish.
An analogy is the difference
between an assembly worker on a production line who views only
one step in the process and a craftsman who guides the product
from beginning to end.
The craftsman has his own system of
putting together a product, whereas the assembly worker has
the system imposed upon him.
.PP
After you are acquainted with the basic tools available in
UNIX and have spent some time using them, you can design
additional tools to perform work that you think is necessary
and helpful.
To create these tools, you will write shell scripts
that use the resources of UNIX in special ways.
We think there
is a certain satisfaction that comes with accomplishing such
tasks by computer.
It seems to us to reward careful thought.
.PP
What programming means to us is that when we confront a problem
that normally submits only to tedium or brute force, we think
of a way to get the computer to solve the problem.
Doing this
often means looking at the problem in a more general way and
solving it in a way that can be applied again and again.
.PP
One of the most important books on UNIX is
.I "The UNIX Programming Environment"
by Brian W. Kernighan and Rob Pike.
They write that
what makes UNIX effective \(lqis an approach to programming,
a philosophy of using the computer.\(rq At the heart of this
philosophy \(lqis the idea that the power of a system comes more
from the relationships among programs than from the programs
themselves.\(rq
.PP
When we talk about building a document preparation system,
it is this philosophy that we are trying to apply.
As a
consequence, this is a system that has great flexibility and
gives the builders a feeling of breaking new ground.
The UNIX
text-processing environment is a system that can be tailored to
the specific tasks you want to accomplish.
In many instances,
it can let you do just what a word processor does.
In many more
instances, it lets you use more of the computer to do things
that a word processor either can't do or can't do very well.