"...the '==' has to be used for numeric and 'eq' in case of strings."

Yes, '==' for numeric, 'eq' for strings, and '=' for assignments.

Years ago, I learned a good trick for avoiding this kind of error: 

if ($query_str='') {
    ...
}

[download]
when, in fact, you meant to say: 
if ($query_str == '') {
    ...
}

[download]

If you get in the habit of always putting the constant on the left side of the '==' sign: 

if ('' == $query_str) {
    ...
}

[download]
then, if you accidentally drop one of the '=', you'll get an error: 
if ('' = $query_str) {
    ...
}

# Produces:
#   Can't modify constant item in scalar assignment at example.pl line
+ 3,
#   near "$query_str) "
#   Execution of example.pl aborted due to compilation errors.

[download]
I don't usually make the mistake of writing '=' where I meant '==', but whenever I do, thanks to putting the constant on the left side, the compiler now let's me know about it in no uncertain terms!
s''(q.S:$/9=(T1';s;(..)(..);$..=substr+crypt($1,$2),2,3;eg;print$..$/

In reply to Re: CGI problem by liverpole
in thread CGI problem by Anonymous Monk

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