Change 21835 by [EMAIL PROTECTED] on 2003/12/02 22:18:05
FAQ sync.
Affected files ...
... //depot/perl/pod/perlfaq1.pod#48 edit
... //depot/perl/pod/perlfaq2.pod#66 edit
... //depot/perl/pod/perlfaq3.pod#78 edit
... //depot/perl/pod/perlfaq4.pod#91 edit
... //depot/perl/pod/perlfaq5.pod#55 edit
Differences ...
==== //depot/perl/pod/perlfaq1.pod#48 (text) ====
Index: perl/pod/perlfaq1.pod
--- perl/pod/perlfaq1.pod#47~21456~ Wed Oct 15 12:19:05 2003
+++ perl/pod/perlfaq1.pod Tue Dec 2 14:18:05 2003
@@ -1,6 +1,6 @@
=head1 NAME
-perlfaq1 - General Questions About Perl ($Revision: 1.12 $, $Date: 2003/07/09
15:47:28 $)
+perlfaq1 - General Questions About Perl ($Revision: 1.14 $, $Date: 2003/11/23
08:02:29 $)
=head1 DESCRIPTION
@@ -60,7 +60,7 @@
no longer maintained; its last patch (4.036) was in 1992, long ago and
far away. Sure, it's stable, but so is anything that's dead; in fact,
perl4 had been called a dead, flea-bitten camel carcass. The most
-recent production release is 5.8.1 (although 5.005_03 and 5.6.1 are
+recent production release is 5.8.2 (although 5.005_03 and 5.6.2 are
still supported). The most cutting-edge development release is 5.9.
Further references to the Perl language in this document refer to the
production release unless otherwise specified. There may be one or
@@ -102,6 +102,8 @@
differences between perl5 and ponie. Ponie is not a complete rewrite
of perl5.
+For more details, see http://www.poniecode.org/
+
=head2 What is perl6?
At The Second O'Reilly Open Source Software Convention, Larry Wall
@@ -307,9 +309,11 @@
(Well, OK, maybe it's not quite that distinct, but you get the idea.)
If you want support and a reasonable guarantee that what you're
developing will continue to work in the future, then you have to run
-the supported version. As of October 2003 that means running either
-5.8.1 (released in September 2003), or one of the older releases like
-5.6.1 (released in April 2001) or 5.005_03 (released in March 1999),
+the supported version. As of December 2003 that means running either
+5.8.2 (released in November 2003), or one of the older releases like
+5.6.2 (also released in November 2003; a maintenance release to let perl
+5.6 compile on newer systems as 5.6.1 was released in April 2001) or
+5.005_03 (released in March 1999),
although 5.004_05 isn't that bad if you B<absolutely> need such an old
version (released in April 1999) for stability reasons.
Anything older than 5.004_05 shouldn't be used.
==== //depot/perl/pod/perlfaq2.pod#66 (text) ====
Index: perl/pod/perlfaq2.pod
--- perl/pod/perlfaq2.pod#65~21283~ Thu Sep 18 14:29:23 2003
+++ perl/pod/perlfaq2.pod Tue Dec 2 14:18:05 2003
@@ -1,6 +1,6 @@
=head1 NAME
-perlfaq2 - Obtaining and Learning about Perl ($Revision: 1.20 $, $Date: 2003/01/26
17:50:56 $)
+perlfaq2 - Obtaining and Learning about Perl ($Revision: 1.25 $, $Date: 2003/10/16
04:57:38 $)
=head1 DESCRIPTION
@@ -407,10 +407,9 @@
announcements, contests, and much more. I<TPJ> has columns on web
development, databases, Win32 Perl, graphical programming, regular
expressions, and networking, and sponsors the Obfuscated Perl Contest
-and the Perl Poetry Contests. As of mid-2001, the dead tree version
-of TPJ will be published as a quarterly supplement of SysAdmin
-magazine ( http://www.sysadminmag.com/ ) For more details on TPJ,
-see http://www.tpj.com/
+and the Perl Poetry Contests. Beginning in November 2002, TPJ moved to a
+reader-supported monthly e-zine format in which subscribers can download
+issues as PDF documents. For more details on TPJ, see http://www.tpj.com/
Beyond this, magazines that frequently carry quality articles on
Perl are I<The Perl Review> ( http://www.theperlreview.com ),
==== //depot/perl/pod/perlfaq3.pod#78 (text) ====
Index: perl/pod/perlfaq3.pod
--- perl/pod/perlfaq3.pod#77~21391~ Tue Sep 30 05:47:13 2003
+++ perl/pod/perlfaq3.pod Tue Dec 2 14:18:05 2003
@@ -1,6 +1,6 @@
=head1 NAME
-perlfaq3 - Programming Tools ($Revision: 1.35 $, $Date: 2003/08/24 05:26:59 $)
+perlfaq3 - Programming Tools ($Revision: 1.37 $, $Date: 2003/11/24 19:55:50 $)
=head1 DESCRIPTION
@@ -65,7 +65,7 @@
installed distributions, although it can take awhile to do
its magic. The standard library which comes with Perl just
shows up as "Perl" (although you can get those with
-Mod::CoreList).
+Module::CoreList).
use ExtUtils::Installed;
==== //depot/perl/pod/perlfaq4.pod#91 (text) ====
Index: perl/pod/perlfaq4.pod
--- perl/pod/perlfaq4.pod#90~21454~ Wed Oct 15 12:06:05 2003
+++ perl/pod/perlfaq4.pod Tue Dec 2 14:18:05 2003
@@ -1,6 +1,6 @@
=head1 NAME
-perlfaq4 - Data Manipulation ($Revision: 1.52 $, $Date: 2003/10/02 04:44:33 $)
+perlfaq4 - Data Manipulation ($Revision: 1.54 $, $Date: 2003/11/30 00:50:08 $)
=head1 DESCRIPTION
@@ -362,9 +362,20 @@
=head2 How do I get a random number between X and Y?
-Use the following simple function. It selects a random integer between
-(and possibly including!) the two given integers, e.g.,
-C<random_int_in(50,120)>
+C<rand($x)> returns a number such that
+C<< 0 <= rand($x) < $x >>. Thus what you want to have perl
+figure out is a random number in the range from 0 to the
+difference between your I<X> and I<Y>.
+
+That is, to get a number between 10 and 15, inclusive, you
+want a random number between 0 and 5 that you can then add
+to 10.
+
+ my $number = 10 + int rand( 15-10+1 );
+
+Hence you derive the following simple function to abstract
+that. It selects a random integer between the two given
+integers (inclusive), For example: C<random_int_in(50,120)>.
sub random_int_in ($$) {
my($min, $max) = @_;
@@ -415,14 +426,6 @@
return 1+int((((localtime(shift || time))[5] + 1899))/1000);
}
-You can also use the POSIX strftime() function which may be a bit
-slower but is easier to read and maintain.
-
- use POSIX qw/strftime/;
-
- my $week_of_the_year = strftime "%W", localtime;
- my $day_of_the_year = strftime "%j", localtime;
-
On some systems, the POSIX module's strftime() function has
been extended in a non-standard way to use a C<%C> format,
which they sometimes claim is the "century". It isn't,
@@ -1489,16 +1492,11 @@
Use the rand() function (see L<perlfunc/rand>):
- # at the top of the program:
- srand; # not needed for 5.004 and later
-
- # then later on
$index = rand @array;
$element = $array[$index];
-Make sure you I<only call srand once per program, if then>.
-If you are calling it more than once (such as before each
-call to rand), you're almost certainly doing something wrong.
+Or, simply:
+ my $element = $array[ rand @array ];
=head2 How do I permute N elements of a list?
==== //depot/perl/pod/perlfaq5.pod#55 (text) ====
Index: perl/pod/perlfaq5.pod
--- perl/pod/perlfaq5.pod#54~20611~ Mon Aug 11 01:33:13 2003
+++ perl/pod/perlfaq5.pod Tue Dec 2 14:18:05 2003
@@ -1,6 +1,6 @@
=head1 NAME
-perlfaq5 - Files and Formats ($Revision: 1.28 $, $Date: 2003/01/26 17:45:46 $)
+perlfaq5 - Files and Formats ($Revision: 1.30 $, $Date: 2003/11/23 08:07:46 $)
=head1 DESCRIPTION
@@ -153,8 +153,10 @@
=head2 How can I manipulate fixed-record-length files?
-The most efficient way is using pack() and unpack(). This is faster than
-using substr() when taking many, many strings. It is slower for just a few.
+The most efficient way is using L<pack()|perlfunc/"pack"> and
+L<unpack()|perlfunc/"unpack">. This is faster than using
+L<substr()|perlfunc/"substr"> when taking many, many strings. It is
+slower for just a few.
Here is a sample chunk of code to break up and put back together again
some fixed-format input lines, in this case from the output of a normal,
@@ -162,22 +164,23 @@
# sample input line:
# 15158 p5 T 0:00 perl /home/tchrist/scripts/now-what
- $PS_T = 'A6 A4 A7 A5 A*';
- open(PS, "ps|");
- print scalar <PS>;
- while (<PS>) {
- ($pid, $tt, $stat, $time, $command) = unpack($PS_T, $_);
- for $var (qw!pid tt stat time command!) {
- print "$var: <$$var>\n";
+ my $PS_T = 'A6 A4 A7 A5 A*';
+ open my $ps, '-|', 'ps';
+ print scalar <$ps>;
+ my @fields = qw( pid tt stat time command );
+ while (<$ps>) {
+ my %process;
+ @[EMAIL PROTECTED] = unpack($PS_T, $_);
+ for my $field ( @fields ) {
+ print "$field: <$process{$field}>\n";
}
- print 'line=', pack($PS_T, $pid, $tt, $stat, $time, $command),
- "\n";
+ print 'line=', pack($PS_T, @[EMAIL PROTECTED] ), "\n";
}
-We've used C<$$var> in a way that forbidden by C<use strict 'refs'>.
-That is, we've promoted a string to a scalar variable reference using
-symbolic references. This is okay in small programs, but doesn't scale
-well. It also only works on global variables, not lexicals.
+We've used a hash slice in order to easily handle the fields of each row.
+Storing the keys in an array means it's easy to operate on them as a
+group or loop over them with for. It also avoids polluting the program
+with global variables and using symbolic references.
=head2 How can I make a filehandle local to a subroutine? How do I pass filehandles
between subroutines? How do I make an array of filehandles?
End of Patch.
