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Postings from April 2010
In-Reply-To: Message from Andy Dougherty <doughera@lafayette.edu>
of "Tue, 06 Apr 2010 10:43:55 EDT."
<alpine.DEB.2.00.1004061008040.31516@fractal.phys.lafayette.edu>
> On Tue, 6 Apr 2010, Nicholas Clark wrote:
>> What is the default nroff line length?
> I believe it traditionally has been 65 characters. (Well, 6.5 inches,
> with 10 characters per inch.) However, most lines (except for headings)
> also end up indented by some amount (traditionally 5 characters), and
> items in a list (such as this list in perfunc.pod) are indented further.
> Contending against this, that line is in a verbatim block, and is rendered
> in "nofill" mode, so it can overflow the 65 character limit. What happens
> then is not well defined.
I tested nroff output not input exactly because of what you point out:
in practice, it is difficult to know beforehand which lines will wind
up being "too long", since this varies depending on surrounding context.
> Practically speaking, either will probably render ok on most man page
> viewers these days.
I believe you're right, Andy, and information won't be lost; I know of no
system where lines are truncated as could once upon a time occur. Still,
neither horizontal scrolling nor wrapping at screen-edge is as pleasing
to the eye as carefully doing so manually, so I try to do that whenever
reasonable--just as I do with these postings.
Though still widely followed, Henry's original Ten Commandments for C
Programmers did *not* include the now-apocryphal directive that "Thou
shalt forever honor the punchcard's 80-column limit and keep it wholly."
Dennis once famously remarked, "The notion of a 'record' is an obsolete
remnant of the days of the 80-column card." And Larry notably quipped,
"You want it in one line? Does it have to fit in 80 columns? :-)"
--tom
/*
* use font "monospace";
*/
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With EXPR, it returns some extra information that |
the debugger uses to print a stack trace. The |
value of EXPR indicates how many call frames to go |
back before the current one. |
|
# 0 1 2 3 4 |
($package, $filename, $line, $subroutine, $hasargs, |
|
# 5 6 7 8 9 10 |
$wantarray, $evaltext, $is_require, $hints, $bitmask, $hinthash)
= caller($i); |
|
Here $subroutine may be "(eval)" if the frame is |
not a subroutine call, but an "eval". In such a |
case additional elements $evaltext and $is_require |
are set: $is_require is true if the frame is |
created by a "require" or "use" statement, |
$evaltext contains the text of the "eval EXPR" |
statement. In particular, for an "eval BLOCK" |
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SEE ALSO
"Tool Talk" by Peter Collinson; p. 22 of SunExpert Magazine, August 1998.
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