Man-width on terminals

Man-width on terminals

[Juri Linkov]

Terminals don't necessarily have 80 columns nowadays but man.el still
limits the width of the formatted man pages to 80 columns on non-window
systems, and it's impossible to override this with an user option.

I propose to remove this restriction that treats terminals as a special case,
and to allow terminals using all available horizontal space (defined by
`window-width').  This also allows using an existing user option `Man-width'
to define any other desired width equally on terminals and window systems:

Index: lisp/man.el
===================================================================
RCS file: /sources/emacs/emacs/lisp/man.el,v
retrieving revision 1.172
diff -u -w -b -r1.172 man.el
--- lisp/man.el	13 Sep 2007 08:04:38 -0000	1.172
+++ lisp/man.el	8 Nov 2007 00:54:16 -0000
@@ -763,7 +764,6 @@
 	;;               minal (using an ioctl(2) if available, the value of
 	;;               $COLUMNS,  or falling back to 80 characters if nei-
 	;;               ther is available).
-	(if window-system
 	    (unless (or (getenv "MANWIDTH") (getenv "COLUMNS"))
 	      ;; This isn't strictly correct, since we don't know how
 	      ;; the page will actually be displayed, but it seems
@@ -773,7 +773,7 @@
 				  ((and (integerp Man-width) (> Man-width 0))
 				   Man-width)
 				  (Man-width (frame-width))
-				  ((window-width)))))))
+			      ((window-width))))))
 	(setenv "GROFF_NO_SGR" "1")
 	(if (fboundp 'start-process)
 	    (set-process-sentinel

-- 
Juri Linkov
http://www.jurta.org/emacs/

Re: Man-width on terminals

[Robert J. Chassell]

    ... allow terminals using all available horizontal space ...

That does not make much sense since the fix does not seem to increase
inter-line whitespace along with line length.

The purpose of limiting line lengths is to prevent needing too much
inter-line whitespace.

Readers tend to lose track of where they are -- unless there is enough
inter-line white space for whatever length of line they use.  This
does not apply to all readers, of course, just to most.  Printers have
found that out over the past five hundred years.  That is why books
have lines that are no more than twice or so the length of an alphabet
(that measure is an old printer's rule of thumb).

With more inter-line whitespace, you can have longer lines.  The
maximum reasonable length for the contents of a line with lots of
inter-line whitespace turned out to be about 70 characters.  Computer
terminals have the whitespace needed, so they are seldom narrow.  And,
for the same reason, terminals seldom had more than 80 characters.
(That is also why cards on which FORTRAN was written had only 80
characters.)

Of course, if you wish to make your manual page width be less than 70
characters, that is fine.  I am against long lines that need more
inter-line whitespace than many writers provide.

-- 
    Robert J. Chassell                          GnuPG Key ID: 004B4AC8
    bob@rattlesnake.com                         bob@gnu.org
    http://www.rattlesnake.com                  http://www.teak.cc

Re: Man-width on terminals

[Juri Linkov]

> With more inter-line whitespace, you can have longer lines.  The
> maximum reasonable length for the contents of a line with lots of
> inter-line whitespace turned out to be about 70 characters.  Computer
> terminals have the whitespace needed, so they are seldom narrow.  And,
> for the same reason, terminals seldom had more than 80 characters.
> (That is also why cards on which FORTRAN was written had only 80
> characters.)
>
> Of course, if you wish to make your manual page width be less than 70
> characters, that is fine.  I am against long lines that need more
> inter-line whitespace than many writers provide.

As an xterm can have arbitrary width, users are free to resize it to the
comfortable width.  And I think Man should fill the text to a width
preferred by the user (there is a special option `Man-width').

-- 
Juri Linkov
http://www.jurta.org/emacs/