Remove $FreeBSD$: two-line .h pattern

Remove /^\s*\*\n \*\s+\$FreeBSD\$$\n/

Add a "B" suffix to memory quantities in top(1) output.

Otherwise small quantities look nonsensical. For instance, when
swapping in a single page we would print "4096 In".

Fix code indentation while here.

MFC after: 1 week
Sponsored by: The FreeBSD Foundation

Fix multiple warnings in usr.bin/top about variables shadowing global
declarations from base gcc, by renaming those variables.

MFC after: 1 week

Fix multiple warnings in usr.bin/top about discarded qualifiers from
both clang and gcc, by either constifying variables, or when that is not
possible, using __DECONST.

MFC after: 1 week

top(1): increase number of columns for memory

The original intention was 4 columns but with a usable a result. In
practice this was not the case. Increase the number of columns to 5
until humanize_number learns alternative ways of presenting the number.

Requested by: many
Ref D15801

top(1): rollback r335836

Encoding-specific processing introduced in r335836 is not recommended.
And doing getenv("LANG") and assuming an encoding based on it is a
very bad practice to internationalize software.

Submitted by: hrs
Differential Revision: https://reviews.freebsd.org/D16203

Fix build: utf8strvisx() does signed data comparisons, but 'char' type
is unsigned in riscv GCC, so use guaranted signed char type.

Sponsored by: DARPA, AFRL

top(1) - support UTF-8 display

Reviewed by: eadler
Approved by: gnn (mentor)
Differential Revision: https://reviews.freebsd.org/D16006

top(1): reimplement header formatting as sbuf

The current header formatting is a giant format string that changes
global state during the format process.

Make the following changes:
- use sbuf to build up the header rather than use the above
pseudo-dynamic one
- Change name length to 10
- Reduce size of RES and SIZE by making humanize more aggressive
- Restore a version number line to the copyright. This may be required
by the copyright (and may not be; its unclear)

This is also a pre-req to implementing TOPCOLOR from newer versions of
top(1)

Discussed with: allanjude, rpolka, danfe, rgrimes
Differential Revision: https://reviews.freebsd.org/D15801

top(1): remove unneeded logic

- remove __pure annotations I added earlier for some functions. One
writes to the the arguments as "out" pointers. The
other reads from an array, which while const within the function might
be mutated externally.
- total_change is modified to be at 1, if previously 0, so no if check
is needed.

top(1): style(9)

- split return type from function name
- Sprinkle a __pure where possible.

top(1): add myself to authors

At this point I've mucked enough with top(1) that all bugs should be
blamed on me rather than William LeFebvre.

top(1): shift from atoi to non-deprecated function

top(1): replace homegrown itoa with sprintf

Much of this should be inlined to the callsite, but leave it here for
now to make it easier to make it easier bisect later.

top(1): format_time, format_k, etc.

- Use humanize_number for format_k and format_k2
- Fix some style nits in format_time

top(1): remove trailing whitespace

top(1): style and related

- style(9)
- remove now-defunct comments
- remove getuid check for low delay
- expand range of format_k

top(1): handle 0 in "digits" functions

top(1): correctly reset per-cpu counters

I had changed this from a for loop to a memset during an earlier
cleanup. This change was incorrect so revert it.

While here, clean up

Reported by: flo

top(1): fix several style & const related issues

- use parens for return
- put function names on newline
- sprinkle const where possible

top(1): Use strsep instead of homegrown alternative

This replaces some complex, and not quite correct logic, with a more
common strsep pattern.

Reviewed by: mmacy (older version)

top(1): another pass of cleanup

- avoid the need to call a function to get size of known array. I'll
likely re-arrange some of the indirect in a later to avoid the magic
constants.
- use correct type
- add const
- replace caddr_t with void*. This corrects an alignment warning.
- remove duplicated include from immediately prior commit

Under base clang we're now down to:
- 3 warning in top.c, 1 warning in mahcine.c, 4 warning in display.c,
- 1 warning in utils.c

Tested with base clang, gcc7, gcc9, base gcc (mips)

top(1): top warnings and cleanup

- Add const where helpful
- add missing 'static' for file-local functions
- use nitems where possible
- convert manual abort() to assert
- use strndup instead of homegrown version

Tested with clang, gcc7, and gcc9

top(1): partial revert of r334517

In fixing issues with uid > INT_MAX, I broke the uid without username
case. The latter is more important so return the old state.

Discussed with: allanjude

top(1): misc minor improvements

- use bool instead of int [0]
- use calloc correctly [0]
(this also caught an incorrect sizeof argument) [1]
- use size_t over int [2]
- correct style

Reported by: pfg [0], scan-build [1], gcc [2]

top(1): cleanup memory allocation and warnings

- Prefer calloc over malloc. This is more predicable and we're not in a
performance sensitive context. [1]
- Remove bogus comment (obsolete from prior commit). [2]
- Remove void casts and type casts of NULL
- Remove redundant declaration of 'quit'
- Add additional const

Reported by: kib [1], vangyzen [2]

top: add -p option and p command to only show a single process

Allow to show only a single process specified by PID. This could
be done either by running top like 'top -p PID' or using the 'p' command
inside top.

Reviewed by: eadler
Approved by: eadler
Obtained from: OpenBSD
Differential Revision: https://reviews.freebsd.org/D15501

Use stpcpy instead of home grown solution

top(1): const poison

top(1) has a number of issues with writing to const strings. Begin
helping this along by marking easy cases as const.

top(1): Use uid_t for uid rather than 'int'

Remove unneeded define while here.

top(1): ansify, style(9). and nits

- Prefer using ansi prototypes rather than C prototypes
- Keep type on separate line from name of function
- Try to keep things const where possible. This will help get to WARNS=6
- switch to "bool" where it makes sense

top(1): add myself as a MAINTAIENR

also fix some nits

top(1): fix several more warnings

top(1): Quiesce several warnings

This is all warnings at level six (6) that are not
char-subscripts, incompatible-pointer-types,
sign-compare, switch, int-conversion,
missing-variable-declarations, cast-qual, cast-align

Some warnings that are fixed by this commit are:
shadow, strict-prototypes, missing-prototypes, pointer-arith,
unused-parameter, unused-const-variable, and several others

top(1): remove use of 'register' keyword

This keyword is meaningless is obscures future diffs that help clear up
warnings in top.

top(1): unconditionally assume we are running on FreeBSD

This allows us to remove a special header and more specifically just the
system headers we want.

top(1): assume that we're building on FreeBSD

This allows us to avoid the ifdefs that we set unconditionally.

top(1): Migrate top to usr.bin

We've been maintaining top(1) for a long time, and the upstream
hasn't existed/been used in similarly as long. Make it clear that we own
top(1)

Tested with 'make universe'. Everything passed except MIPS which failed
for unrelated reasons. Install also tested for amd64.

Reviewed by: sbruno
No objections: imp, mmacy
Differential Revision: https://reviews.freebsd.org/D15387