This is what i get when i type in your code -
192-168-1-7:~ rav$ diskutil list
/dev/disk0
#: TYPE NAME SIZE IDENTIFIER
0: GUID_partition_scheme *1.0 TB disk0
1: EFI EFI 209.7 MB disk0s1
2: Apple_HFS Macintosh HD 696.5 GB disk0s2
3: Apple_Boot Recovery HD 650.0 MB disk0s3
/dev/disk1
#: TYPE NAME SIZE IDENTIFIER
0: Apple_partition_scheme *16.1 MB disk1
1: Apple_partition_map 32.3 KB disk1s1
2: Apple_HFS Flash Player 16.0 MB disk1s2
192-168-1-7:~ rav$ diskutil cs list
No CoreStorage logical volume groups found
192-168-1-7:~ rav$ sudo gpt -vv r- show /dev/disk0
gpt: unknown command: r-
192-168-1-7:~ rav$