Plan 9 from Bell Labs’s /usr/web/sources/patch/applied/install-restructurised/isventiarenas
#!/bin/rc if(! ~ $#* 1){ echo 'usage: isventiarenas /dev/sdC0/part' >[1=2] exit usage } arg=$1 if(! cmp -s <{dd -quiet 1 -if $arg -bs 1024 -iseek 256 | dd -quiet 1 -bs 4 -count 1 | xd -b | sed 1q} <{echo '0000000 a9 e4 a5 e7'}) exit notarenas exit 0