On 20/09/2011 01:11, Parag Kalra wrote:
I was getting this error message for one of my script.
The reason came out out to be, I had not place a semi-colon at the end of
try-catch block.
try {
something
} catch some_exception {
do something
}
After I placed the semi-colon, I am no longer getting this error (Can't use
string ("1") as a HASH ref while "strict refs")
try {
something
} catch some_exception {
do something
};
My questions is I have quite a few scripts that are using the SAME try-catch
block without a semi-colon but those are working seamlessly. They why was I
getting the error for only this try-catch block.
Is there some rule which we need to follow while using try-catch in Perl?
Hi Parag
The first problem I see is that you are passing 'catch' the return value
of the subroutine 'some_exception' when it expects a code block. The
correct syntax is
try {
<some code that may cause an exception>
}
catch {
<handle exception passed in $_>
}
The way try / catch works is obscure, and presented in Programming Perl
as an example of how subroutine prototypes could be useful, but the
declaration of try looks like
sub try (&$);
so to express its functionality your code should be formatted like this
try (
{ <some code that may cause an exception> },
catch ({
<handle exception passed in $_>
})
);
which clearly requires a semicolon after the closing parenthesis.
For me, the bottom line is that try / catch is a funky showpiece that
pushes Perl syntax beyond its limits. No one who sees your code will
thank you for using it, and you should remove it in preference of a
simple check on $@.
It cannot be a good sign if you don't understand where the semicolons
should go!
HTH,
Rob
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