Zhao, Bingfeng wrote:
Hello,
Hello,
I encounter following requirements:
1. accept customized perl sentences;
2. provide variables exchange between customized perl sentences and my
routine.
Here is a sample:
[code]
use strict;
use warnings;
# we use $_ to pass value in and out
$_ = qw/foo/;
Why are you assigning a list to a scalar? Perhaps you meant:
$_ = q/foo/;
Or:
$_ = qq/foo/;
my $cmds = "print $_; $_ = qw/bar/";
Scalar variables are interpolated in double quoted strings so $cmds will
be assigned the string 'print foo; foo = qw/bar/' which won't work
correctly because you don't have a 'foo' filehandle and you can't use
barewords (because of strict) or assign to them.
eval {$cmds};
eval {} is used to evaluate valid perl code but you have a single scalar
variable in void context, hence the message "variable in void context".
You want to do this instead:
eval $cmds;
my $result = $_;
print $result;
[/code]
But I got a error: Useless use of private variable in void context at
ss.pl line 7. So how can I do? Thanks in advance.
John
--
Perl isn't a toolbox, but a small machine shop where you
can special-order certain sorts of tools at low cost and
in short order. -- Larry Wall
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