bin: Automated cleanup of cdefs and other formatting

Apply the following automated changes to try to eliminate
no-longer-needed sys/cdefs.h includes as well as now-empty
blank lines in a row.

Remove /^#if.*\n#endif.*\n#include\s+<sys/cdefs.h>.*\n/
Remove /\n+#include\s+<sys/cdefs.h>.*\n+#if.*\n#endif.*\n+/
Remove /\n+#if.*\n#endif.*\n+/
Remove /^#if.*\n#endif.*\n/
Remove /\n+#include\s+<sys/cdefs.h>\n#include\s+<sys/types.h>/
Remove /\n+#include\s+<sys/cdefs.h>\n#include\s+<sys/param.h>/
Remove /\n+#include\s+<sys/cdefs.h>\n#include\s+<sys/capsicum.h>/

Sponsored by: Netflix

bin: Remove ancient SCCS tags.

Remove ancient SCCS tags from the tree, automated scripting, with two
minor fixup to keep things compiling. All the common forms in the tree
were removed with a perl script.

Sponsored by: Netflix

Remove $FreeBSD$: one-line .c pattern

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

sh: Avoid some headers when NO_HISTORY is set.

This is more simpler compatibility with using this source on older
systems before libedit was made to install filecomplete.h in
commit b315a7296d2.

sh: implement persistent history storage

Implement persistent history storage:
the strategy is simple at start: loads the existing .sh_history file
at exit dump it.

The implementation respects the HISTFILE variable and its POSIX
definition: ~/.sh_history is used if HISTFILE is not set.

to avoid sh to create the history file, set HISTSIZE to 0 or HISTFILE to
en empty value

Co-authored-by: pstef
Reviewed by: jilles
Differential Revision: https://reviews.freebsd.org/D29493

sh: fix debug build

Approved by: jilles

sh: Keep ignored SIGINT/SIGQUIT after set in a background job

If job control is not enabled, a background job (... &) ignores SIGINT and
SIGQUIT, but this can be reverted using the trap builtin in the same shell
environment.

Using the set builtin to change options would also revert SIGINT and SIGQUIT
to their previous dispositions.

This broke due to r317298. Calling setsignal() reverts the effect of
ignoresig().

Reported by: bdrewery
MFC after: 1 week

sh: Do not ignore INTOFF during a trap

INTOFF postpones SIGINT processing and INTON enables it again. This is
important so an interactive shell can return to the top level prompt when
Ctrl+C is pressed.

Given that INTON is automatically done when a builtin completes, the part
where onsig() ignores suppressint when in_dotrap is true is both unnecessary
and unsafe. If the trap is for some other signal than SIGINT, arbitrary code
could have been interrupted.

Historically, INTOFF remained in effect for longer.

Reviewed by: bdrewery
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D25270

General further adoption of SPDX licensing ID tags.

Mainly focus on files that use BSD 3-Clause license.

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.

Special thanks to Wind River for providing access to "The Duke of
Highlander" tool: an older (2014) run over FreeBSD tree was useful as a
starting point.

sh: Enable interrupts before executing EXIT trap and doing final flush.

sh: Simplify setinteractive().

setsignal() does nothing if the signal disposition is already set correctly.

Renumber copyright clause 4

Renumber cluase 4 to 3, per what everybody else did when BSD granted
them permission to remove clause 3. My insistance on keeping the same
numbering for legal reasons is too pedantic, so give up on that point.

Submitted by: Jan Schaumann <jschauma@stevens.edu>
Pull Request: https://github.com/freebsd/freebsd/pull/96

sh: Fix use-after-free if a trap replaces itself.

MFC after: 1 week

sh: Fix the trap builtin to be POSIX-compliant for 'trap exit SIG' and 'trap n n...'.

The parser considered 'trap exit INT' to reset the default for both EXIT and
INT. This beahvior is not POSIX compliant. This was avoided if a value was
specified for 'exit', but then disallows exiting with the signal received. A
possible workaround is using ' exit'.

However POSIX does allow this type of behavior if the parameters are all
integers. Fix the handling for this and clarify its support in the manpage
since it is specifically allowed by POSIX.

Differential Revision: https://reviews.freebsd.org/D2325
Reviewed by: jilles
MFC after: 2 weeks

sh: Abort a wait builtin on any trapped signal.

This is required by POSIX.

PR: 197210
Reported by: ache
MFC after: 2 weeks

sh: Move some code from onint() to onsig(), making onint() noreturn.

As a result, the INTON macro which is used many times generates fewer
bytes of code.

sh: Eliminate some gotos.

sh: Remove SIGWINCH handler and just check for resize before every read.

The SIGWINCH handler triggers breakage in libedit which is hard to fix; see
PR bin/169773.

Also, window size changes while a program is in foreground (and it rather
than sh will receive SIGWINCH) will now be picked up automatically.

Downside: it is now certain that a resize is only processed after pressing
<Enter>. If libedit is fixed, sh will most likely have to be changed also.

PR: bin/180146

sh: Allow trapping SIGINT/SIGQUIT after ignore because of '&'.

If job control is not enabled, background jobs started with ... & ignore
SIGINT and SIGQUIT so that they are not affected by such signals that are
intended for the foreground job. However, this should not prevent
reassigning a different action for these signals (as if the shell invocation
inherited these signal actions from its parent).

Austin group issue #751

Example:
{ trap - INT; exec sleep 10; } & wait
A Ctrl+C should terminate the sleep command.

sh: Fix race condition with signals and wait or set -T.

The change in r238888 was incomplete. It was still possible for a trapped
signal to arrive before the shell went to sleep (sigsuspend()) because a
check was missing or because the signal arrived before in_waitcmd was set.

On SMP, this bug sometimes caused the builtins/wait4.0 test to take 1 second
to execute; it then might or might not fail. On UP, the test almost always
failed.

sh: Remove #define MKINIT.

MKINIT only served for the removed mkinit. Many variables can be static now.

sh: Fix various compiler warnings.

It now passes WARNS=7 with clang on i386.

GCC 4.2.1 does not understand setjmp() properly so will always trigger
-Wuninitialized. I will not add the volatile keywords to suppress this.

sh: When executing a trap, keep exit status along with evalskip.

This ensures 'return' in a trap returns the correct status to the caller.

If evalskip is not set or if it is overridden by a previous evalskip, keep
the old behaviour of restoring the exit status from before the trap.

sh: If a SIGINT or SIGQUIT interrupts "wait", return status 128+sig.

sh: Fix EINTR race condition in "wait" and "set -T" using sigsuspend().

When waiting for child processes using "wait" or if "set -T" is in effect, a
signal interrupts the wait. Make sure there is no window where the signal
handler may be invoked (setting a flag) just before going to sleep.

There is a similar race condition in the shell language, but scripts can
avoid it by exiting from the trap handler or enforcing synchronization using
a fifo.

If SIGCHLD is not trapped, a signal handler must be installed for it. Only
install this handler for the duration of the wait to avoid triggering
unexpected [EINTR] errors elsewhere.

Note that for some reason only SIGINT and SIGQUIT interrupt a "wait"
command. This remains the case.

sh: Reset pendingsigs before checking pending traps, not after.

Otherwise, a signal arriving at exactly the right moment might not be
processed until another signal arrived.

sh: Fix execution of multiple statements in a trap when evalskip is set

Before this fix, only the first statement of the trap was executed if
evalskip was set. This is for example the case when:
o "-e" is set for this shell
o a trap is set on EXIT
o a function returns 1 and causes the script to abort

Reviewed by: jilles
MFC after: 2 weeks

sh: Fix out of bounds array access when trap is used with an invalid signal.

MFC after: 1 week

sh: Fix duplicate prototypes for builtins.

Have mkbuiltins write the prototypes for the *cmd functions to builtins.h
instead of builtins.c and include builtins.h in more .c files instead of
duplicating prototypes for *cmd functions in other headers.

sh: Remove special code for shell scripts without magic number.

These are called "shell procedures" in the source.

If execve() failed with [ENOEXEC], the shell would reinitialize itself
and execute the program as a script. This requires a fair amount of code
which is not frequently used (most scripts have a #! magic number).
Therefore just execute a new instance of sh (_PATH_BSHELL) to run the
script.

Make sys_signame upper case.

This matches the constants from <signal.h> with 'SIG' removed, which POSIX
requires kill and trap to accept and 'kill -l' to write.

'kill -l', 'trap', 'trap -l' output is now upper case.

In Turkish locales, signal names with an upper case 'I' are now accepted,
while signal names with a lower case 'i' are no longer accepted, and the
output of 'killall -l' now contains proper capital 'I' without dot instead
of a dotted capital 'I'.

sh: If exit is used without args from a trap action, exit on the signal.

This is useful so that it is easier to exit on a signal than to reset the
trap to default and resend the signal. It matches ksh93. POSIX says that
'exit' without args from a trap action uses the exit status from the last
command before the trap, which is different from 'exit $?' and matches this
if the previous command is assumed to have exited on the signal.

If the signal is SIGSTOP, SIGTSTP, SIGTTIN or SIGTTOU, or if the default
action for the signal is to ignore it, a normal _exit(2) is done with exit
status 128+signal_number.

sh: Fix some things about -- in trap:
* Make 'trap --' do the same as 'trap' instead of nothing.
* Make '--' stop option processing (note that '-' action is not an option).

Side effect: The error message for an unknown option is different.

sh: Make 'trap -l' look like 'kill -l'.

sh: Make exit without parameters from EXIT trap POSIX-compliant.

It should use the original exit status, just like falling off the
end of the trap handler.

Outside an EXIT trap, 'exit' is still equivalent to 'exit $?'.

sh: Add a function to print warnings (with command name and newline).
This is like error() but without raising an exception.
It is particularly useful as a replacement for the warnx macro in
bltin/bltin.h.

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

In the spirit of r90111, depend on c89 and remove the "STATIC" macro
and its usage.

Consistently use "STATIC" for all functions in order to be able to set
breakpoints with in a debugger. And use naked "static" for variables.

Noticed by: bde

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.

trap: do not consider a bad signal name a fatal error.
POSIX explicitly prescribes this.
Continue processing any other signals and return status 1.

sh: Use sigaction instead of signal/siginterrupt combination.

Don't skip forking for an external command if any traps are active.

Example:
sh -c '(trap "echo trapped" EXIT; sleep 3)'
now correctly prints "trapped".

With this check, it is no longer necessary to check for -T
explicitly in that case.

This is a useful bugfix by itself and also important because I plan to
skip forking more often.

PR: bin/113860 (part of)
PR: bin/74404 (part of)
Reviewed by: stefanf
Approved by: ed (mentor)

Fix the eval command in combination with set -e. Before this change the shell
would always terminate if eval returned with a non-zero exit status regardless
if the status was actually tested. Unfortunately a new file-scope variable
is needed, the alternative would only be to add a new parameter to all
built-ins.

PR: 134881

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

Whitespace nits.

Correctly quote the output when showing the installed trap actions.

PR: 74043
Submitted by: Jilles Tjoelker

Various small code cleanups resulting from a code reviewing
and linting procedure:

1. Remove useless sub-expression:

- if (*start || (!ifsspc && start > string && (nulonly || 1))) {
+ if (*start || (!ifsspc && start > string)) {

The sub-expression "(nulonly || 1)" always evaluates to true and
according to CVS logs seems to be just a left-over from some
debugging and introduced by accident. Removing the sub-expression
doesn't change semantics and a code inspection showed that the
variable "nulonly" is also not necessary here in any way (and the
expression would require fixing instead of removing).

2. Remove dead code:

- if (backslash && c == '\\') {
- if (read(STDIN_FILENO, &c, 1) != 1) {
- status = 1;
- break;
- }
- STPUTC(c, p);
- } else if (ap[1] != NULL && strchr(ifs, c) != NULL) {
+ if (ap[1] != NULL && strchr(ifs, c) != NULL) {

Inspection of the control and data flow showed that variable
"backslash" is always false (0) when the "if"-expression is
evaluated, hence the whole block is effectively dead code.
Additionally, the skipping of characters after a backslash is already
performed correctly a few lines above, so this code is also not
needed at all. According to the CVS logs and the ASH 0.2 sources,
this code existed in this way already since its early days.

3. Cleanup Style:

- ! trap[signo][0] == '\0' &&
+ ! (trap[signo][0] == '\0') &&

The expression wants to ensure the trap is not assigned the empty
string. But the "!" operator has higher precedence than "==", so the
comparison should be put into parenthesis to form the intended way of
expression. Nevertheless the code was effectively not really broken
as both particular NUL comparisons are semantically equal, of course.
But the parenthesized version is a lot more intuitive.

4. Remove shadowing variable declaration:

- char *q;

The declaration of symbol "q" hides another identical declaration of
"q" in the same context. As the other "q" is already reused multiple
times and also can be reused again without negative side-effects,
just remove the shadowing declaration.

5. Just small cosmetics:

- if (ifsset() != 0)
+ if (ifsset())

The ifsset() macro is already coded by returning the boolean result
of a comparison operator, so no need to compare this boolean result
again against a numerical value. This also aligns the macros usage to
the remaining existing code.

Reviewed by: stefanf@

Remove clause 3 from the UCB licenses.

OK'ed by: imp, core

style(9): wrap at 80 columns.

Handle proper formatting and a buffer overrun when running an old sh on
a system that has sys_nsig > NSIG (i.e. when libc is upgraded.)

Submitted by: Matt Dillon
Reviewed by: bde

Use sys_nsig instead of NSIG for the length of the signal arrays. This
is important if we add new signals later. From DragonflyBSD:
jobs.c:1.4, trap.c:1.3.

Obtained from: DragonflyBSD

Avoid calling el_resize() from a signal handler, even though libedit
itself does that if you set EL_SIGNAL. Instead, set a flag and check it
before calling el_gets(). This is safer, but slower to respond to changes.

Pointed out by: mp

Catch SIGWINCH in interactive shells and call el_resize() to update
libedit's idea of the window size.

Remove broken and incomplete support for old releases of System V,
don't support system that implement getcwd(3) with a pipe to /bin/pwd.

Consistently use FBSDID

o __P has been reoved
o Old-style K&R declarations have been converted to new C89 style
o register has been removed
o prototype for main() has been removed (gcc3 makes it an error)
o int main(int argc, char *argv[]) is the preferred main definition.
o Attempt to not break style(9) conformance for declarations more than
they already are.
o Change
int
foo() {
...
to
int
foo(void)
{
...

$Id$ -> $FreeBSD$

Various spelling/formatting changes.

Submitted by: Philippe Charnier <charnier@xp11.frmug.org>

The immediate execution of traps I introduced in September 1998 (to
make /etc/rc interruptible in cases when programs hang with blocked
signals) isn't standard enough.

It is now switched off by default and a new switch -T enables it.

You should update /etc/rc to the version I'm about to commit in a few
minutes to keep it interruptible.

Narrow down conditions to break wait() to process traps.
Improve comments.

Fix an inefficiency I introduced in my last commit.
Include "expand.h" vom memalloc.c to pull function declartion into scope

If traps are set, they are now executed even when a signal-blocking
foreground child is running. Formerly, traps were exceuted after the
next child exit.

The enables the user to put a breaking wrapper around a blocking
application:
(trap 'echo trap ; exit 1' 2; ./pestyblocker; echo -n)

The "echo -n" after the child call is needed to prevent sh from
optimizing the trap-executing shell away. I'm working on this.

Improve bookkeeping of in_waitcmd and style fixes.
Submitted by: Bruce Evans

Re-enable killing childs with SIGQUIT. Spotted by Bruce Evans.

Do not exit on SIGINT in non-interactive shells, fixes PR 1206,
i.e. this makes emacs usable from system(3). Programs called from
shellscripts are now required to exit with proper signal status. That
means, they have to kill themself. Exiting with faked numerical exit
code is not sufficient.

Exit with proper signal status if script exits on signal.

Make the wait builtin interruptable, both with and without traps set.

Use volatile sig_atomic_t where (and only where) appropriate.

(Almost) fix printing of newlines on SIGINT.

Make traps setable from trap handlers. This is needed for shellscripts
that catch SIGINT for cleanup work but intend to exit on it, hance
have to kill themself from a trap handler. I.e. mkdep.

While I'm at it, make it -Wall clean. -Wall is not enabled in
Makefile, since vararg warnx() macro calls in usr.bin/printf/printf.c
are not -Wall-able.
PR: 1206
Obtained from: Basic SIGINT fix from Bruce Evans

Add rcsid. Spelling.

Fixed some type and value mismatches. setsignal() returned a bogusly
cast value that was always ignored. Rev.1.9 of trap.c made this
more bogus by returning a semantically different value after calling
siginterrupt(). Avoid these problems by not returning a value.

1) Fix longstanding bug:
trap 'echo xxx' 1 2 3 15
read x
is not interrupted by ^C (due to restartable read syscall) and must be
interrupted per POSIX
Worse case:
read -t 5 x
hangs forever after ^C pressed (supposed to timeout after 5 secs)
Fixed by adding siginterrupt(signo, 1) after catch handler installed

2) Do not reinstall sighandler immediately after it is called,
BSD do it for us

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.

With these changes sh(1)'s trap command should be POSIX-compliant,
while remaining (becoming :) compatible with other popular shells.
Specifically these changes include:

1) Implement 'trap -l' to get a list of valid signals names. This
is useful if you wanted to do something like reset all signal
handlers to there defaults values, in which case something like
this will do the trick.

trap `trap -l`

2) Reformat the output of 'trap' so it can be saved and later eval'd
to restore the saved settings.

3) Allow the use of signal names as well as signal numbers.

4) Fix trap handling of SIGCHLD so that commands like the following
(albeit, contrived) won't cause sh(1) to recurse ad infinitum.

trap uname 0 20

5) Make variables static that are used only in trap.c.

6) Minor 'style(9) police' mods.

Merge in NetBSD mods and -Wall cleaning.

Obtained from: NetBSD, me

Merge of 4.4-Lite2 sh source, plus some gcc -Wall cleaning. This is a
merge of parallel duplicate work by Steve Price and myself. :-]

There are some changes to the build that are my fault... mkinit.c was
trying (poorly) to duplicate some of the work that make(1) is designed to
do. The Makefile hackery is my fault too, the depend list was incomplete
because of some explicit OBJS+= entries, so mkdep wasn't picking up their
source file #includes.

This closes a pile of /bin/sh PR's, but not all of them..

Submitted by: Steve Price <steve@bonsai.hiwaay.net>, peter

Import the 4.4BSD-Lite2 /bin/sh sources

Requested by: joerg

(Note, this is mostly going to be conflicts, which is expected. Our entire
sh source has a mainline, so this should not change anything except for
a few new files appearing. I dont think they are a problem)

Remove trailing whitespace.

Reviewed by: phk

Added $Id$

BSD 4.4 Lite bin Sources