Re: Net::SSH2 test connection to remote host

See eval:

my $ssh2 = Net::SSH2->new();
my $res = eval { $ssh2->connect($server)); 1 };
if (my $err = $@) {
    warn "There was an error connecting to $server: $err";
};
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Comment on Re: Net::SSH2 test connection to remote host Download Code

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Re^2: Net::SSH2 test connection to remote host by derby (Abbot) on Sep 30, 2008 at 11:49 UTC
Corion what's with the `1` as the last statement in the eval? I don't think I've come across that idiom. -derby	[reply] [d/l]
Re^3: Net::SSH2 test connection to remote host by Corion (Patriarch) on Sep 30, 2008 at 11:52 UTC
The `; 1` is to make sure I get a true value no matter what the function returns. If it fails, I think there are cases where the block still might return a true value, but I don't know.	[reply] [d/l]
Re^4: Net::SSH2 test connection to remote host by JavaFan (Canon) on Sep 30, 2008 at 12:06 UTC
But as it, it's an example of cargo-cult. Sure, $res is true if and only if the eval doesn't fail, but you're not using its result. Instead, you rely on $@ to determine failure. But the entire '; 1' idiom is there because relying on $@ to determine failure can trigger both false positives and false negatives. The correct idiom is: `my $res = eval {...statements...; 1}; unless ($res) { ... eval failed ... }` [download]	[reply] [d/l]
Re^5: Net::SSH2 test connection to remote host by salva (Canon) on Sep 30, 2008 at 15:45 UTC
Re^6: Net::SSH2 test connection to remote host by JavaFan (Canon) on Sep 30, 2008 at 21:20 UTC
Some notes below your chosen depth have not been shown here
Re^6: Net::SSH2 test connection to remote host by kyle (Abbot) on Sep 30, 2008 at 15:53 UTC
Re^2: Net::SSH2 test connection to remote host by james_ (Novice) on Sep 30, 2008 at 10:59 UTC
Thanks for the quick response Corion, that worked perfectly!	[reply]