Re: When to use anonymous references
On Wed, 28 Apr 2010 01:16:16 -0400, Uri Guttman wrote:
>> "PS" == Peter Scott writes:
>
> PS> On Mon, 26 Apr 2010 22:16:27 +0800, Tim Bowden wrote:
> >> I've just realised I almost never use named arrays or hashes
> >> anymore. It's almost always anonymous references instead. That
> >> lead me to wonder what criteria experienced perl hackers have as to
> >> when to use a named array or hash, and when to start with an
> >> anonymous ref instead. My very informal criteria tends to be to
> >> use an anonymous ref from the start if I'm going to be passing it
> >> to a sub, and a named array or hash otherwise. I've found the
> >> former to be much more common. Thoughts?
>
> PS> I create arrays and hashes by default, not references to anonymous
> PS> versions. I'd sooner not be putting arrows in unnecessarily. I
> can PS> always enreference an aggregate in the call to a sub.
>
> my choice is usually based on usage. if i am building up data
> structures, the members are almost always anon refs - no need to have
> named vars for them.
Right. I should have said that I don't create named references, most of
the time, but anon references as part of a data structure, sure. In
other words, I very rarely do
my $some_ref = \anything or [anything] or {anything}
as in the original post.
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Re: Interactive shell in Perl
I installed psh but getting following error after launching it: Cannot find termcap: TERM not set at C:\perl\lib/Term/ReadLine.pm line 351 Cheers, Parag On Wed, Apr 28, 2010 at 7:45 AM, John W. Krahn wrote: > Parag Kalra wrote: > >> Hey All, >> > > Hello, > > > Wanted to know if Perl has any interactive shell (just like Python, Bash, >> Ruby etc have) by any chance. And if yes how do we invoke that. >> > > perldoc -q "Is there a Perl shell" > > > John > -- > The programmer is fighting against the two most > destructive forces in the universe: entropy and > human stupidity. -- Damian Conway > > > -- > To unsubscribe, e-mail: beginners-unsubscr...@perl.org > For additional commands, e-mail: beginners-h...@perl.org > http://learn.perl.org/ > > >
Re: Redirecting the Output and Error of Perl script
Parag Kalra wrote: Thanks all... I was printing in normal fashion. I should have used something lik: print STDERR "stderr\n"; as suggested by all. Perhaps you should be using warn and die: warn "This appears on STDERR\n"; -- Just my 0.0002 million dollars worth, Shawn Programming is as much about organization and communication as it is about coding. I like Perl; it's the only language where you can bless your thingy. Eliminate software piracy: use only FLOSS. -- To unsubscribe, e-mail: beginners-unsubscr...@perl.org For additional commands, e-mail: beginners-h...@perl.org http://learn.perl.org/
Re: Redirecting the Output and Error of Perl script
Thanks all... I was printing in normal fashion. I should have used something lik: print STDERR "stderr\n"; as suggested by all. Cheers, Parag On Sat, May 1, 2010 at 1:55 AM, Philip Potter wrote: > On 30 April 2010 18:45, Parag Kalra wrote: > > Hey All, > > > > I am trying to execute a Perl via shell script. I want to redirect output > of > > Perl script to one file and error occured (if any) to other file. > > > > This is the snippet from my shell script: > > > > perl output_error.pl 1>> Report.log 2>>Error.log > > > > What you have written works for me. I think your error is somewhere else. > > $ cat foo.pl > #!perl > > print "stdout\n"; > print STDERR "stderr\n"; > > $ perl foo.pl 1>> out 2>> err > $ cat out > stdout > $ cat err > stderr > > Note that >> appends to the end of a file, while > replaces the file. > > Phil >
Re: testing if divisible by?
> "JLP" == Jamie L Penman-Smithson writes:
JLP> On Sat, 2010-05-01 at 07:15 -0400, Paul wrote:
>> Hello all. How can I test to see if a number is divisible by say, 40?
JLP> Use the modulo operator:
JLP> my $a = 40;
JLP> my $b = 1;
JLP> if ($a % $b == 0) {
no need for the == 0 if you invert the test with unless or change the
print text.
JLP> print "$b is divisible by $a\n";
JLP> }
uri
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Re: testing if divisible by?
On Sat, 2010-05-01 at 07:15 -0400, Paul wrote:
> Hello all. How can I test to see if a number is divisible by say, 40?
Use the modulo operator:
my $a = 40;
my $b = 1;
if ($a % $b == 0) {
print "$b is divisible by $a\n";
}
-j
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Re: testing if divisible by?
On 1 May 2010 12:15, Paul wrote: > Hello all. How can I test to see if a number is divisible by say, 40? > Thanks. Use the modulo operator %. Given integers $x and $y, the expression $x % $y gives the remainder when $x is divided by $y. As a result, if (and only if) $x is exactly divisible by $y, $x % $y is equal to 0. #!perl use 5.010; # for 'say' say 5 % 2; say 6 % 2; say 7 % 2; say 79 % 40; say 80 % 40; say 81 % 40; For more information, see http://perldoc.perl.org/perlop.html#Multiplicative-Operators Phil -- To unsubscribe, e-mail: beginners-unsubscr...@perl.org For additional commands, e-mail: beginners-h...@perl.org http://learn.perl.org/
Re: testing if divisible by?
Paul wrote: Hello all. How can I test to see if a number is divisible by say, 40? Thanks. See `perldoc perlop` and search for /Multiplicative Operators/ Read the part about the % operator. -- Just my 0.0002 million dollars worth, Shawn Programming is as much about organization and communication as it is about coding. I like Perl; it's the only language where you can bless your thingy. Eliminate software piracy: use only FLOSS. -- To unsubscribe, e-mail: beginners-unsubscr...@perl.org For additional commands, e-mail: beginners-h...@perl.org http://learn.perl.org/
testing if divisible by?
Hello all. How can I test to see if a number is divisible by say, 40? Thanks. -- To unsubscribe, e-mail: beginners-unsubscr...@perl.org For additional commands, e-mail: beginners-h...@perl.org http://learn.perl.org/
Re: Redirecting the Output and Error of Perl script
On 30 April 2010 18:45, Parag Kalra wrote: > Hey All, > > I am trying to execute a Perl via shell script. I want to redirect output of > Perl script to one file and error occured (if any) to other file. > > This is the snippet from my shell script: > > perl output_error.pl 1>> Report.log 2>>Error.log > What you have written works for me. I think your error is somewhere else. $ cat foo.pl #!perl print "stdout\n"; print STDERR "stderr\n"; $ perl foo.pl 1>> out 2>> err $ cat out stdout $ cat err stderr Note that >> appends to the end of a file, while > replaces the file. Phil -- To unsubscribe, e-mail: beginners-unsubscr...@perl.org For additional commands, e-mail: beginners-h...@perl.org http://learn.perl.org/
