Exactly what is your input data? is it the hex number 0x1e5, (485 decimal), or the string "0x1e5" ?

Perl handles these two differently so try running these one liners, and it might make things clearer

    perl -E 'my $x=0x1e5; say $x;'
# will print 485

    perl -E 'my $x="0x1e5"; say $x;'
#will print 0x1e5
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