in reply to Two values for same variables in %in hash

I guess that the ReadParse is from CGI. If that is the case, multiple values under a key are concatenated together using the ASCII 0 character (NUL Byte): 

perl -MCGI -le 'CGI::ReadParse();
    print for split /\0/, $in{myname}' \
    'idx=8&args=&myname=ABCD.txt&idx=+&myname=foobar'

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Output:

ABCD.txt
foobar

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