$ perl -le'$x = "hexadecimal addr:0xdf7780 value"; print $x; $x =~ s/ addr:0x \K ( [[:xdigit:]]+ ) / sprintf "%x", hex( $1 ) + 0x500000000 /xe; print $x'
hexadecimal addr:0xdf7780 value
hexadecimal addr:0x500df7780 value