Executing a string as a Perl command

[tel2]

Hi Monks,

What is a simple way to execute a string as a Perl command, in a Perl script?

For example, let's say I have a scalar assignment like this:

$cmd = '$var1 = 5;';

If I want to execute $cmd, ending up with $var1 containing 5, what's an easy way to do it, (without parsing the string, picking out the variable & value, and making the assignment with an indirect reference).  I've looked at 'eval', and other posts here, but can't find anything appropriate yet.

Thanks.
Tel2

[ikegami]

That's exactly what eval EXPR does.

[tel2]

Thanks guys,

Before creating this thread, I had made the mistake of testing it like this:

perl -e '$cmd = "$var1 = 5;";eval $cmd;print $var1'

but of course that failed because of the double quotes.  So now I've changed it to this:

perl -e '$cmd = q[$var1 = 5;];eval $cmd;print $var1'

which works just like a bought one.

Thanks for your help.

tel2

[johnpeterdinesh]

Please try below code

my $cmd = '$var1 = 5';

eval "$cmd";

print $var1;

[JavaFan]

Why the double quotes? eval $cmd; works fine, no need for an additional stringification.

[ww]

1. ...and your point (aside from the fact that your code prints "5") is...?
2. ... and this is better than

   my $var1 = 5;
   print $var1;
   

   how?

[educated_foo]

What's wrong with "eval"?