1) Remove the return-value-enum, which is not necessary for a simple
program like this.
2) Don't disallow both l and s to be specified. This is undefined
behaviour defined by POSIX, so we don't start demanding things
from the user.
3) Replace exit() with return (we are in main).
4) Refactor main loop to never return in the loop, but actually
set the same-value and break, which increases readability.
5) Remove the final fclose()'s. The OS will take care of them, no
need to become cleansy here.
6) Use idiomatic return-value using same. This concludes the
increase of readability in the main-loop.
The algorithm had some areas which had potential for improvement.
This should make cmp(1) faster.
There have been changes to behaviour as well:
1) If argv[0] and argv[1] are the same, cmp(1) returns Same.
2) POSIX specifies the format of the difference-message to be:
"%s %s differ: char %d, line %d\n", file1, file2,
<byte number>, <line number>
However, as cmp(1) operates on bytes, not characters, I changed
it to
"%s %s differ: byte %d, line %d\n", file1, file2,
<byte number>, <line number>
This is one example where the standard just keeps the old format
for backwards-compatibility. As this is harmful, this change
makes sense in the sense of consistentcy (and because we take
the difference of char and byte very seriously in sbase, as
opposed to GNU coreutils).
The manpage has been annotated, reflecting the second change, and
sections shortened where possible.
Thus I marked cmp(1) as finished in README.
It actually makes the binaries smaller, the code easier to read
(gems like "val == true", "val == false" are gone) and actually
predictable in the sense of that we actually know what we're
working with (one bitwise operator was quite adventurous and
should now be fixed).
This is also more consistent with the other suckless projects
around which don't use boolean types.
FRIGN
sin
Hiltjo Posthuma
stateless
Christoph Lohmann
Connor Lane Smith