utility compares two files of any type and writes the results
to the standard output.
is silent if the files are the same; if they differ, the byte
and line number at which the first difference occurred is reported.
Bytes and lines are numbered beginning with one.
The following options are available:
Do not follow symbolic links.
Print the byte number (decimal) and the differing
byte values (octal) for each difference.
Print nothing for differing files; return exit
but prints in hexadecimal and using zero as index
for the first byte in the files.
For regular files compare file sizes first, and fail the comparison if they
are not equal.
The optional arguments
are the byte offsets from the beginning of
respectively, where the comparison will begin.
The offset is decimal by default, but may be expressed as a hexadecimal
or octal value by preceding it with a leading ``0x'' or ``0''.