how `crc' is actually defined.
Data type corrections:
- Define variables which contain file byte offset values as type
off_t as required by the `crc' function.
- Change the type of a variable carrying a CRC checksum from `u_long'
to `uint32_t'.
- Parse the length of a file with sscanf as `intmax_t'
(as there is no conversion specifier for `off_t').
Style(9):
- Put an empty line between #include directives for system and user
header files.