MFC r333157: cmp(1): Provide some long options

These match GNU cmp(1) for compatibility where applicable.

Future work might implement the -i option from GNU cmp(1) to express skip
either in terms of both files or of the form "SKIP1:SKIP2" rather than
specifying them as additional arguments to cmp(1).

Revert r330897:

This was intended to be a non-functional change. It wasn't. The commit
message was thus wrong. In addition it broke arm, and merged crypto
related code.

Revert with prejudice.

This revert skips files touched in r316370 since that commit was since
MFCed. This revert also skips files that require $FreeBSD$ property
changes.

Thank you to those who helped me get out of this mess including but not
limited to gonzo, kevans, rgrimes.

Requested by: gjb (re)

Partial merge of the SPDX changes

These changes are incomplete but are making it difficult
to determine what other changes can/should be merged.

No objections from: pfg

Copy head@r302406 to stable/11 as part of the 11.0-RELEASE cycle.
Prune svn:mergeinfo from the new branch, as nothing has been merged
here.

Additional commits post-branch will follow.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Remove the advertising clause from UCB copyrighted files in usr.bin. This
is in accordance with the information provided at
ftp://ftp.cs.berkeley.edu/pub/4bsd/README.Impt.License.Change

Also add $FreeBSD$ to a few files to keep svn happy.

Discussed with: imp, rwatson

Add a -h option to tell cmp not to follow symbolic links.

MFC after: 3 weeks
Sponsored by: Sophos/ActiveState

ANSIify function definitions to avoid a warning.

No need to check for "-" explicitly in getopt() loop.

Exit >1 when an error occurs, regardless of whether -s is specified (SUSv3)

remove __P

Style improvements recommended by Bruce as a follow up to some
of the recent WARNS commits. The idea is:

1) FreeBSD id tags should follow vendor tags.
2) Vendor tags should not be compiled (though copyrights probably should).
3) There should be no blank line between including cdefs and __FBSDIF.

Turn on WARNS=2.
Use __FBSDID().

Make filenames const to avoid a few warnings.
Add FreeBSD tags.

Reviewed by: cmp

Fix a bug introduced in rev 1.8, where special files ended up
being treated like regular files because of missing braces.

PR: 20143

Add the -z flag to check file sizes first
Correct the cmp.1 usage message
Correct the -l/-s incompatibility message

Submitted by: Mark Knight <markk@knigma.org>

Let cmp(1) grow in -x option to print differences in contemporarry hex
format rather than the mixed decimal/octal format of -l.

Tweaks to allow compiling -Wall (mostly adding "const" to char rcsid[]).

Permit hex/octal parameters to cmp, to match what the manual page says.

PR: 3850, 3855

Correct usage string. Program name converted to bold in man page.

compare return value from getopt against -1 rather than EOF, per the final
posix standard on the topic.

I don't like what they did to cmp(1) in 4.4 Lite; now it whines all
the time, even with -s. Make cmp SHUT UP about non-existant files
when run with -s.
Submitted by: jkh

This commit was generated by cvs2svn to compensate for changes in r1590,
which included commits to RCS files with non-trunk default branches.

BSD 4.4 Lite Usr.bin Sources