#!/usr/bin/perl -p -i
# s/(xyz\s*=\s*)(\d+)/$1.($2+1)/e;

/xyz/?s/(\d+)/$1+1/e:1;
[download]

Updated:CheeseLord beat me to it.
Update 2: Found a shorter one

/\/\averick
perl -l -e "eval pack('h*','072796e6470272f2c5f2c5166756279636b672');"