MFC r326276:

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.

MFC r308806

Speed up pw operations that edit /etc/group or /etc/passwd

r285050 fixed a bug in pw that could lead to /etc/passwd or /etc/group
corruption on power loss. However, it fixed it by opening those files with
O_SYNC, which is very slow, especially on ZFS. This change replaces O_SYNC with
appropriately placed fsync()s instead, which is much faster. Using a ZFS
tmpdir, the time to run pw's kyua tests drops from 245s to 35s.

MFC r307752

Close some file descriptor leaks in pw

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

Cleanup a bit includes

Add a new global struct pwconf to store etcpath, rootdir and struct userconf

Do not add anymore -R and -V to arglist
Add an error message if both -V and -R are set in arguments

Remove uneeded intermediate variable

Remove some uneeded headers

Simplify string duplication: use strdup instead of malloc + strcpy

Submitted by: db
Approved by: cperciva
MFC after: 2 weeks

Teach pw(8) about how to use pw/gr API to reduce code duplication

MFC after: 2 months

Unbreak group operations by reverting previous delta which removed the
assignment of `l' in `gr_update' to the return value of snprintf. It
claimed to have fixed the case where snprintf returned -1--in fact, it
broke the entire routine. Not setting `l' here causes fileupdate() to
invariably fail with EINVAL because it does its own check to assert
that the parameter isn't -1.

Handle snprintf() returning -1.

MFC after: 2 weeks

Clean up error handling in fileupdate(), which now returns 0 on success
instead of a boolean. This replicated through he front-end sub-functions
relating to add, delete, modify entries in passwd & group files
Errno is now preserved so output of errc()/warnc() will be less obfuscated
by subsequent errors when reporting the problem.

Add more intelligent error handling when attempting to modify/delete NIS
entries with no corresponding local database entry.

[MFC to stable in a couple of weeks to keep both in sync]

$Id$ -> $FreeBSD$

1) Do not blindly ignore file update errors which may occur due to concurrent
updating
2) Add -V <etcdir>, which allows maintaining user/group database in alternate
locations other than /etc.

Use err(3) instead of local redefinition. Add rcsid string.

Revert $FreeBSD$ to $Id$

Make the long-awaited change from $Id$ to $FreeBSD$

This will make a number of things easier in the future, as well as (finally!)
avoiding the Id-smashing problem which has plagued developers for so long.

Boy, I'm glad we're not using sup anymore. This update would have been
insane otherwise.

1) 200 users per group limitation removed and pw
will handle lines of any length in /etc/group.
2) Fixed bug with usermod -d not updating user's home
directory.
3) Minor formatting display changes/fixes with *show -P.

This commit was generated by cvs2svn to compensate for changes in r20302,
which included commits to RCS files with non-trunk default branches.

Copyright update by the author, to be more in line with our sample
copyright.

Submitted by: David Nugent

pw(8) -- a backend utility to manage the user and group databases.

sysinstall's new User&group menu will use it, hence it's a 2.2
candidate despite of providing new functionality.

Submitted by: David L. Nugent, <davidn@blaze.net.au>