How can I use switch -s and 'use strict' at the same time

[Ting Wang]

Hi,
I am learning to use switches of perl and I met
following question. I hope someone can help me.


I am trying to use switch -s with use strict, i
wrote two scripts like:

#--- script 1 ----
#!/usr/bin/perl -s
use strict;
print $xyz;

#--- script 2 ----
#!/usr/bin/perl -s
use strict;
my $xyz;
print $xyz;

Both of the codes can not be run.
Is there a chance using both -s and 'use strict'
at the same time?


Thanks

 

[Paul Lalli]

I am trying to use switch -s with use strict, i
wrote two scripts like:

#--- script 1 ----
#!/usr/bin/perl -s
use strict;
print $xyz;

#--- script 2 ----
#!/usr/bin/perl -s
use strict;
my $xyz;
print $xyz;

Both of the codes can not be run.

This is a remarkably poor error description. How can they not be run?
Syntax errors? Incorrect output? Your mouse takes on a life of its
own and restrains you from typing at the keyboard?

Have you read the Posting Guidelines for this group?

Is there a chance using both -s and 'use strict'
at the same time?

The -s option sets *global* variables, not lexical. In your script 2
above, -s sets the variable $main::xyz equal to whatever value -xyz was
given on the command line. Then you declare a lexical variable my
$xyz. The two variables are completely unrelated.

Two options:
1) fully qualify the package variable:
print $main::xyz
2) Declare the ability to use the package variable without qualifying,
instead of declaring a new lexical:
our $xyz;
print $xyz;

Paul Lalli

 

[John Bokma]

Two options:
1) fully qualify the package variable:
print $main::xyz
2) Declare the ability to use the package variable without qualifying,
instead of declaring a new lexical:
our $xyz;
print $xyz;

Now and then I try to think up the answer, and don't post it, because
either I am not sure, or I have no time to verify my solution (or both).

I am happy to see that mine equals 2), and thanks for reminding me of 1

 

[Paul Lalli]

Now and then I try to think up the answer, and don't post it, because
either I am not sure, or I have no time to verify my solution (or both).

I am happy to see that mine equals 2), and thanks for reminding me of 1

Heh. I had actually never even heard of -s before. `perldoc perlrun`
wasn't explicit about what kind of variables are set, so I more or less
guessed that it would set globals, and a quick test proved me right.


Paul Lalli

 

[Ting Wang]

Sorry for my poor error description I will
find the guideline to read.

Thanks for you antwort.

 

[John Bokma]

Heh. I had actually never even heard of -s before.

I did, because of Usenet. Some time ago there was a kind of Perl golf
thingy going on (Dutch ng), and I read up again on all those funny
switches.