I am making some changes to old code this week, and I am getting annoyed with my method of socket communications... The old (working) code sent a series of values as a %-delimited string, which is then split on the receiving end into an array. Ugly!
So, I decided to rewrite it quickly to send and receive an array, and do away with the ugly %-delimited string. But it's not working. No errors on either end, but it hangs up the system. A half dozen Google searches later, and I've come to the conclusion that what I'm trying to do is not possible, and that %-delimited string is there for a good reason.
Does anybody here have insight into this? Is my assessment correct? Is there a better way than what currently works?
Phil
I forgot to mention that this is on a server I don't own, and getting modules installed is possible, but very difficult... So much so that I'd rather remain ugly than go through the process of getting another module. :-)
--isotope
sockets know only a series of bits, not data structures.
Okay. That validates my conclusion. Thanks! Unfortunately, Storable suffers the same inconvenience as YAML. At least I'm on the right track now.
Phil
It's not part of our core...
CS/AIX i2mptpr3 $ perl -v
This is perl, v5.6.0 built for aix
...
CS/AIX i2mptpr3 $ perl -e 'use Storable;'
Can't locate Storable.pm in @INC
...
Not quite. Storable suffers completely different inconveniences from YAML. Storable can get tripped up if the levels of Storable on client and server aren't compatable. You have to be a bit careful if the endianness of the client and server are different (I think there's an "nstore" and "nthaw" for network-order storing) - assuming the levels of Storable are otherwise compatable.
But it is part of the core, so it's already installed. That inconvenience is unique to YAML. (Well, unique in the context of YAML vs Storable.)
If you know, 100%, that the % sign will never appear in your data, then what you already have should be enough, shouldn't it? But yes, there are better ways to serialize your data, and YAML and Storable are two ways that work. A naive and straight-forward solution would be to use Data::Dumper and eval:
sub encode {
return Dumper [@_];
}
sub decode {
my $VAR1;
my $string = shift;
return eval "$string";
}
I have not fully tested this method out, but it does work for most complex data structures that involve arrays, hashes, and references to those.
I recommend using more robust ways of serializing your data, such as Storable, YAML, or even XML. But i did feel inclined to post this code, at the very least to see if anyone can see ways to break this code. :)
jeffa
L-LL-L--L-LL-L--L-LL-L-- -R--R-RR-R--R-RR-R--R-RR B--B--B--B--B--B--B--B-- H---H---H---H---H---H--- (the triplet paradiddle with high-hat)
decode("system 'rm -rf /home/jeffa'");
Be careful with using eval() unless you're absolutely sure the string you're evalling is trustworthy. For data recieved from a network socket that level of trust is pretty hard to come by!
-sam
I'm not really a human, but I play one on earth. flash japh
A couple of great links. Thank you. I'd never heard of EasyTCP before.