stat(1): Fix grammar error in stat.c

Event: Advanced UNIX Programming Course (Fall’23) at NTHU
Pull Request: https://github.com/freebsd/freebsd-src/pull/1014

Remove $FreeBSD$: one-line .c pattern

Remove /^[\s*]*__FBSDID\("\$FreeBSD\$"\);?\s*\n/

spdx: The BSD-2-Clause-NetBSD identifier is obsolete, drop -NetBSD

The SPDX folks have obsoleted the BSD-2-Clause-NetBSD identifier. Catch
up to that fact and revert to their recommended match of BSD-2-Clause.

Discussed with: pfg
MFC After: 3 days
Sponsored by: Netflix

usr.bin/stat: Fix error message formatting.

PR: bin/261657
MFC after: 3 days

stat(1): Do not pass S_IFBLK to devname unconditionally

PR: 269190
Reviewed by: kib
MFC after: 1 week

usr.bin/stat: honour locale for "-t %+"

The man page states that "-t %+" prints time information in the same
format as date with no format specifier.

This was not the case, the format used was always that of date for the
POSIX locale.

The fix suggested by the reporter leads to output that matches the
documentation.

Reported by: Jamie Landeg-Jones <jamie@catflap.org>
MFC after: 3 days

Add 'Birth' to 'stat -x' output. Current Linux stat(1)
also includes that.

Reviewed by: cem
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D20130

stat(1): cache id->name resolution

When invoked on a large list of files, it is most common for a small number of
uids/gids to own most of the results.

Like ls(1), use pwcache(3) to avoid repeatedly looking up the same IDs.

Example microbenchmark and non-scientific results:

$ time (find /usr/src -type f -print0 | xargs -0 stat >/dev/null)

BEFORE:
3.62s user 5.23s system 102% cpu 8.655 total
3.47s user 5.38s system 102% cpu 8.647 total

AFTER:
1.23s user 1.81s system 108% cpu 2.810 total
1.43s user 1.54s system 107% cpu 2.754 total

Does this microbenchmark have any real-world significance? Until a use case
is demonstrated otherwise, I doubt it. Ordinarily I would be resistant to
optimizing pointless microbenchmarks in base utilities (e.g., recent totally
gratuitous changes to yes(1)). However, the pwcache(3) APIs actually
simplify stat(1) logic ever so slightly compared to the raw APIs they wrap,
so I think this is at worst harmless.

PR: 230491
Reported by: Thomas Hurst <tom AT hur.st>
Discussed with: gad@

various: general adoption of SPDX licensing ID tags.

Mainly focus on files that use BSD 2-Clause license, however the tool I
was using misidentified many licenses so this was mostly a manual - error
prone - task.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.

No functional change intended.

Use MIN() instead of MAX() as the previous syntax was wrote in a weird and
confused way: "prec > 9 ? 9 : prec".

Submitted by: pfg, ngie and luke <luke.tw@gmail.com>
MFC after: 2 weeks.

Use macro MAX() from sys/param.h.

MFC after: 2 weeks.

Minor fixes to previous change introducing switch -H, as per comments
on -arch.

Reviewed by: gleb

Introduce a new command line switch '-H' for stat(1)
causing arguments to be interpreted as NFS file handles.

Reviewed by: -arch (jhb, eadler)
MFC after: 1 month

More -Wmissing-variable-declarations fixes.

In addition to adding `static' where possible:

- bin/date: Move `retval' into extern.h to make it visible to date.c.
- bin/ed: Move globally used variables into ed.h.
- sbin/camcontrol: Move `verbose' into camcontrol.h and fix shadow warnings.
- usr.bin/calendar: Remove unneeded variables.
- usr.bin/chat: Make `line' local instead of global.
- usr.bin/elfdump: Comment out unneeded function.
- usr.bin/rlogin: Use _Noreturn instead of __dead2.
- usr.bin/tset: Pull `Ospeed' into extern.h.
- usr.sbin/mfiutil: Put global variables in mfiutil.h.
- usr.sbin/pkg: Remove unused `os_corres'.
- usr.sbin/quotaon, usr.sbin/repquota: Remove unused `qfname'.

Synthesize the change from NetBSD's 1.33:

"Do not crash if a date cannot be represented (localtime returning
NULL), use the Epoch value instead."

Obtained from: njoly@NetBSD.org

Bring in the relevant changes from NetBSD's 1.31:

"Use strlcpy, not strncpy, when the desired semantics are strlcpy's
rather than strncpy's."

Note: NetBSD's 1.32 is their adoption of our r216206

Obtained from: dholland@NetBSD.org

Bring in the change from OpenBSD's 1.14:

"synchronize synopsis and usage; "-l", "-r", "-s" and "-x" are mutually
exclusive; while here, slightly improve spacing in the source code
so it fits on a 80-column display again.

diff greatly improved by martynas@"

Obtained from: sobrado@OpenBSD.org

Bring in the following changes from NetBSD. See the discussion at:
http://gnats.netbsd.org/cgi-bin/query-pr-single.pl?number=44128

1.29
"Don't printf time_t with %d; fixes PR 44128 from yamt. With this change it
successfully prints mtimes after 2038."

1.30
"Improve previous with comments."

Obtained from: dholland@NetBSD.org (both)

Fix an "unused variable" error that gets us all the way to WARNS=6

Bring in the update from NetBSD 1.28:

"Fix WARNS=4 issues (-Wcast-qual -Wsign-compare)"

Because of code differences I had to hand-apply parts of the patch,
so responsibility for errors goes to me.

Obtained from: lukem@NetBSD.org

Bring in a new feature, adding a -f option to readlink to print the path
of the target, similar to realpath(1). See the discussion at:
http://gnats.netbsd.org/cgi-bin/query-pr-single.pl?number=34662

This brings in the following changes:
1.24
"PR/34662: martijnb at atlas dot ipv6 dot stack dot nl: readlink doesn't
grok -f, and there's no alternative (+fix)

Patch applied with minor tweak (%y -> %R, as it was already taken) plus
some nits from myself. Thanks!"

Obtained from: elad@NetBSD.org

1.25
"Fix a segfault when doing 'stat -f %R' on the stdin file handle, instead
fake the filename '(stdin)' like the %N format."

Obtained from: mlelstv@NetBSD.org

1.27
"The ofmt variable is actually a bit mask (not the character that was
in the format string) so that we can "or" it with the bits in the
formats variable. This fixes the missing " -> " in front of the real
path (when you use %SR).

Also, the ?: needs another space."

Obtained from: atatat@NetBSD.org

I am purposely omitting the following changes:
1.23 A humanize_number(3) clone that should better be implemented by
actually using humanize_number(3)
1.26 This is the removal of license clause 3 and 4, already handled
by imp in r203971

Bring in the change from NetBSD 1.22:

"Fix a trivial truncation case, and eliminate a corner case that might
print a nul character."

I am purposely bypassing the following versions:
1.19 A build infrastructure change that does not apply to us
1.20 A feature I am not interested in, but don't object if someone else
wants to pick it up
1.21 A build infrastructure change that does not apply to us

Obtained from: atatat@NetBSD.org

Bring in the change from NetBSD 1.18:

"If using stat (the -L flag) and it fails, fall back to lstat(). It
may be the case that we're examining a broken symlink, and anything is
better than nothing."

The changes in 1.14 through 1.17 were not relevant to us.

Obtained from: atatat@NetBSD.org

A new jail(8) with a configuration file, to replace the work currently done
by /etc/rc.d/jail.

MFC r207153: stat: Allow -f %Sf to display the file flags symbolically.

PR: 124349

stat: Allow -f %Sf to display the file flags symbolically.

I have changed the patch slightly to show '-' if there are no flags just
like ls -ldo does.

PR: 124349
Submitted by: Ighighi
MFC after: 1 week

Create the altix project branch. The altix project will add support
for the SGI Altix 350 to FreeBSD/ia64. The hardware used for porting
is a two-module system, consisting of a base compute module and a
CPU expansion module. SGI's NUMAFlex architecture can be an excellent
platform to test CPU affinity and NUMA-aware features in FreeBSD.

The NetBSD Foundation has granted permission to remove clause 3 and 4
from their software.

Obtained from: NetBSD

Let stat(1) use fdevname(3).

Because we now have a reliable library function that converts file
descriptors to character device names, let stat(1) use this. This means
it can now do the following:

$ stat -f %N
/dev/pts/0

I've changed main() to set file properly, so output() is never called
with file set to NULL.

Approved by: dougb (older version, still used devname)

o Print an octal representation of suid, sgid and sticky bits with -x flag.

PR: bin/131569
Submitted by: Jaakko Heinonen
Reported by: Yannick Cadin
MFC after: 1 week

- Import the HEAD csup code which is the basis for the cvsmode work.

Resolve conflicts

Import NetBSD's 1.13 version. This contains no functional changes, just
support for cross and host builds on more platforms.

Obtained from: Andrew Brown <atatat@NetBSD.org>, and Luke Mewburn <lukem@NetBSD.org>

Import NetBSD's 1.10 version, which includes the ability to display
the new inode birthtime field, a few other small cleanups, and
synchronization with our #include <sys/types.h>.

Approved by: re (bmah)
Obtained from: Andrew Brown <atatat@NetBSD.org>

Adjust the size passed to readlink so that the null termination
falls within the range of the path variable.

Cribbed from the latest NetBSD source.

Obtained from: provos@NetBSD.org

I was too conservative with my header changes, so restore some sanity
via bde. atatat@NetBSD.org made basically the same change in their
version, so bring over their CVS Id which I neglected last time.

Obtained from: bde, Andrew Brown <atatat@NetBSD.org>

A cooperative effort...

1. Update the code to the latest from NetBSD, which includes:
* A new command line option to suppress stat(2) errors
* Output is now done via stdio
* Fixes for bitwise OR'ing of letters

2. Andrew from NetBSD merged in our own Johan's readlink patches.

3. Andrew also merged in some brucifications.

I made some small contributions to the header cleanup, and tried
to generally improve the overall style(9)'ishness. I also documented
the new -q option and added the *LINKS to the Makefile.

All responsibility for mistakes in merging the contributions
from the above is mine.

Obtained from: Andrew Brown <atatat@NetBSD.org>, bde, johan

Virgin import of NetBSD's stat(1)