2007fld has asked for the wisdom of the Perl Monks concerning the following question:

I saw a script like this: join ("\n", @$msg ) $msg is just a text message with several lines. What does @$msg mean?

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Re: what does @$ mean?
by kyle (Abbot) on Sep 30, 2008 at 15:49 UTC
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Re: what does @$ mean?
by runrig (Abbot) on Sep 30, 2008 at 15:52 UTC
    $msg is likely a reference to an array of text messages. @$msg dereferences that reference, turning it into an array of text messages. And those messages are joined together in your code example. See perlref and perlreftut.
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Re: what does @$ mean?
by lamp (Chaplain) on Sep 30, 2008 at 16:22 UTC
    '@$msg' dereference the array reference '$msg'.
    'join ("\n", @$msg )' is used for join the '$msg' array reference elements into a string separated by "\n". For eg. 
    #!/usr/bin/perl
use strict;
use warnings;

my $msg = ['apple', 'banana', 'orange']; # array reference
my @msg = @$msg;             # dereferncing the arreay ref

print "Dereferenced: @msg\n";

print join("\n",@$msg);                        # prints the array elem
+ents sperated by "\n".

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    Please go through perlref and join for more information.
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Re: what does @$ mean?
by Your Mother (Archbishop) on Sep 30, 2008 at 19:02 UTC

    What everyone else said + I prefer this syntax: @{$msg} in part because it helps convey what's going on.

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      in part because it helps convey what's going on Not any more or less than @$msg alone
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        The braces make it clear that @$ is not a special sigil; that it's still an array with something going on inside. It also enhances readability on long or compound (deep hash access, for example) variable names. IIRC, there used to be a case where it further was necessary to disambiguate the resolution of variables but I'm not sure about that or if it's still true.

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