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Posted by Jerry Krinock on May 9, 2008, 1:21 pm
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I have written a function to log variables like this:
" varName: varValue"
but it takes two arguments: the variable name as a string, and the
variable symbol:
logVar ("myVar", $myVar) ;
sub logVar {
my $varName = shift ;
my $varValue = shift ;
if (!defined($varValue)) {
$varValue = "<undef>" ;
}
printf ("%16s: %s\n", $varName, $varValue) ;
}
Is there any way to get "myVar" from $myVar or vice versa, without
foregoing 'strict' and 'warnings'?
Note: My actual code uses Std::Log but the problem is the same.
Thanks,
Jerry Krinock
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Posted by A. Sinan Unur on May 9, 2008, 1:43 pm
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98d7-64c1bc9ef4e3@k13g2000hse.googlegroups.com:
> I have written a function to log variables like this:
>
> " varName: varValue"
This is a FAQ:
perldoc -q "How can I use a variable as a variable name"
Sinan
--
(remove .invalid and reverse each component for email address)
comp.lang.perl.misc guidelines on the WWW:
http://www.rehabitation.com/clpmisc/
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Posted by Jens Thoms Toerring on May 9, 2008, 2:21 pm
Please log in for more thread options > 98d7-64c1bc9ef4e3@k13g2000hse.googlegroups.com:
> > I have written a function to log variables like this:
> >
> > " varName: varValue"
> This is a FAQ:
> perldoc -q "How can I use a variable as a variable name"
> Sinan
I think the OP is looking for something a bit different, i.e.
a way to get the name of variable from the variable itself.
I.e. some hypothetical code like
my $x = 10;
logvar( $x );
sub logvar {
my $varref;
print get_name_from_reference( $var ) . " " . $$var . "\n";
}
It's clear that for something like this to work a reference to
the variable has to be passed to the function. But I have no
idea how to write a function like get_name_from_reference()
and also have my doubts that it is possible at all (but then
this is Perl and there's so much magic that it is hard to be
sure;-)
Regards, Jens
--
\ Jens Thoms Toerring ___ jt@toerring.de
\__________________________ http://toerring.de
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Posted by jerrykrinock on May 9, 2008, 3:38 pm
Please log in for more thread options On May 9, 11:21=A0am, j...@toerring.de (Jens Thoms Toerring) wrote:
> I think the OP is looking for something a bit different...
Yes, I am.
> This is a FAQ:
>
> perldoc -q "How can I use a variable as a variable name"
I'd read that, and now studied it further, but I get the impression
that the only solution is to always define all of my variables in my
own hash, just in case I ever decided that I wanted to log one of
them.
That's not going to be any fun, and not very readable by earthlings.
Indeed, this code works:
#!/usr/bin/perl
use strict ;
use warnings ;
my %MY_VARS ;
# New Way to declare a Loggable Variable...
# Instead of just "my $fred",
# I now have to write:
my $fred =3D $MY_VARS ;
# New Way to assign a Loggable Variable
# Instead of just "$fred =3D 23",
# I now have to write:
$MY_VARS =3D 23 ;
# Well, after all that yuck, indeed, as desired,
# I can log it with only one argument, :
logVar("fred") ;
# Using this handy function
sub logVar {
my $varName =3D shift ;
my $varValue =3D $MY_VARS ;
if (!defined($varValue)) {
$varValue =3D "<undef>" ;
}
printf ("%32s: %s\n", $varName, $varValue) ;
}
But it's hardly worth all that massive obfuscation. Can someone
confirm that there is indeed no way to simply log a "regular" variable
and its name without having to type both of them, or is Jens correct
that it can't be done?
Jerry
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Posted by A. Sinan Unur on May 9, 2008, 5:48 pm
Please log in for more thread options jerrykrinock@gmail.com wrote in news:2643728c-7f39-43d9-8c46-
ca63cee3018e@m73g2000hsh.googlegroups.com:
> On May 9, 11:21 am, j...@toerring.de (Jens Thoms Toerring) wrote:
>
>> I think the OP is looking for something a bit different...
>
> Yes, I am.
I jumped the gun, sorry!
Sinan
--
(remove .invalid and reverse each component for email address)
comp.lang.perl.misc guidelines on the WWW:
http://www.rehabitation.com/clpmisc/
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