File: gawk.info,  Node: Conventions,  Next: Manual History,  Prev: This Manual,  Up: Preface

Typographical Conventions
=========================

This Info file is written in Texinfo
(https://www.gnu.org/software/texinfo/), the GNU documentation
formatting language.  A single Texinfo source file is used to produce
both the printed and online versions of the documentation.  This minor
node briefly documents the typographical conventions used in Texinfo.

   Examples you would type at the command line are preceded by the
common shell primary and secondary prompts, '$' and '>', respectively.
Input that you type is shown 'like this'.  Output from the command is
preceded by the glyph "-|".  This typically represents the command's
standard output.  Error messages and other output on the command's
standard error are preceded by the glyph "error->".  For example:

     $ echo hi on stdout
     -| hi on stdout
     $ echo hello on stderr 1>&2
     error-> hello on stderr

   Characters that you type at the keyboard look 'like this'.  In
particular, there are special characters called "control characters."
These are characters that you type by holding down both the 'CONTROL'
key and another key, at the same time.  For example, a 'Ctrl-d' is typed
by first pressing and holding the 'CONTROL' key, next pressing the 'd'
key, and finally releasing both keys.

   For the sake of brevity, throughout this Info file, we refer to Brian
Kernighan's version of 'awk' as "BWK 'awk'."  (*Note Other Versions::
for information on his and other versions.)

Dark Corners
------------

     Dark corners are basically fractal--no matter how much you
     illuminate, there's always a smaller but darker one.
                         -- _Brian Kernighan_

   Until the POSIX standard (and 'GAWK: Effective AWK Programming'),
many features of 'awk' were either poorly documented or not documented
at all.  Descriptions of such features (often called "dark corners") are
noted in this Info file with "(d.c.)."  They also appear in the index
under the heading "dark corner."

   But, as noted by the opening quote, any coverage of dark corners is
by definition incomplete.

   Extensions to the standard 'awk' language that are supported by more
than one 'awk' implementation are marked "(c.e.)," and listed in the
index under "common extensions" and "extensions, common."