Copy stable/9 to releng/9.3 as part of the 9.3-RELEASE cycle.

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

MFC r248349: sh: Recognize "--" and explicitly reject options in wait
builtin.

If syntactically invalid job identifiers are to be taken as jobs that exited
with status 127, this should not apply to options, so that we can add
options later if need be.

MFC r230998,r233792: sh: Use vfork in a few common cases.

This uses vfork() for simple commands and command substitutions containing a
single simple command, invoking an external program under certain conditions
(no redirections or variable assignments, non-interactive shell, no job
control). These restrictions limit the amount of code executed in a vforked
child.

Various incarnations of this patch have been shown to bring performance
improvements:
http://lists.freebsd.org/pipermail/freebsd-hackers/2012-January/037581.html

The use of vfork() can be disabled by setting a variable named
SH_DISABLE_VFORK.

Copy head to stable/9 as part of 9.0-RELEASE release cycle.

Approved by: re (implicit)

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: Save/restore changed variables in optimized command substitution.

In optimized command substitution, save and restore any variables changed by
expansions (${var=value} and $((var=assigned))), instead of trying to
determine if an expansion may cause such changes.

If $! is referenced in optimized command substitution, do not cause jobs to
be remembered longer.

This fixes $(jobs $!) again, simplifies the man page and shortens the code.

sh: Reduce more needless differences between error messages.

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.

sh: Send messages about signals to stderr.

This is required by POSIX and seems to make more sense.

See also r217557.

sh: Fix signal messages being sent to the wrong file sometimes.

When a foreground job exits on a signal, a message is printed to stdout
about this. The buffer was not flushed after this which could result in the
message being written to the wrong file if the next command was a builtin
and had stdout redirected.

Example:
sh -c 'kill -9 $$'; : > foo; echo FOO:; cat foo

Reported by: gcooper
MFC after: 1 week

sh: Add kill builtin.

This allows specifying a %job (which is equivalent to the corresponding
process group).

Additionally, it improves reliability of kill from sh in high-load
situations and ensures "kill" finds the correct utility regardless of PATH,
as required by POSIX (unless the undocumented %builtin mechanism is used).

Side effect: fatal errors (any error other than kill(2) failure) now return
exit status 2 instead of 1. (This is consistent with other sh builtins, but
not in NetBSD.)

Code size increases about 1K on i386.

Obtained from: NetBSD

sh: Various simplifications to jobs.c:
* Prefer kill(-X) to killpg(X).
* Remove some dead code.
* No additional SIGINT is needed if int_pending() is already true.

No functional change is intended.

sh: Improve internal-representation-to-text code to avoid binary output.

The code to translate the internal representation to text did not know about
various additions to the internal representation since the original ash and
therefore wrote binary stuff to the terminal.

The code is used in the jobs command and similar output.

Note that the output is far from complete and mostly serves for recognition
purposes.

sh: POSIX says there should not be a space between Done and (exitstatus).

(On the other hand, (core dumped) does need a space and so does [1] +.)

sh: Improve jobs output of pipelines.

If describing the status of a pipeline, write all elements of the pipeline
and show the status of the last process (which would also end up in $?).
Only write one report per job, not one for every process that exits.

To keep some earlier behaviour, if any process started by the shell in a
foreground job terminates because of a signal, write a message about the
signal (at most one message per job, however).

Also, do not write messages about signals in the wait builtin in
non-interactive shells. Only true foreground jobs now write such messages
(for example, "Terminated").

sh: Avoid marking a job as done before it is fully created.

In r208489, I added code to reap zombies when forking new processes, to
limit the amount of zombies. However, this can lead to marking a job as done
or stopped if it consists of multiple processes and the first process ends
very quickly. Fix this by only checking for zombies before forking the first
process of a job and not marking any jobs without processes as done or
stopped.

sh: jobs -p: Do not ask the kernel for the pgid.

The getpgid() call will fail if the first process in the job has already
terminated, resulting in output of "-1".

The pgid of a job is always the pid of the first process in the job and
other code already relies on this.

sh: Use <stddef.h> rather than <sys/stddef.h>.

<sys/stddef.h> is only for the kernel and conflicts with <stddef.h>.

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

Make DEBUG traces 64-bit clean:
- Use %t to print ptrdiff_t values.
- Cast a ptrdiff_t value explicitly to int for a field width specifier.

While here, sort includes.

Submitted by: Garrett Cooper

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

sh: Forget about terminated background processes sooner.

Unless $! has been referenced for a particular job or $! still contains that
job's pid, forget about it after it has terminated. If $! has been
referenced, remember the job until the wait builtin has reported its
completion (either with the pid as parameter or without parameters).

In interactive mode, jobs are forgotten after termination has been reported,
which happens before primary prompts and through the jobs builtin. Even
then, though, remember a job if $! has been referenced.

This is similar to what is suggested by POSIX and should fix most memory
leaks (which also tend to cause sh to use more CPU time) with long running
scripts that start background jobs.

Caveats:
* Repeatedly referencing $! without ever doing 'wait', like
while :; do foo & echo started foo: $!; sleep 60; done
will still use a lot of memory and CPU time in the long run.
* The jobs and jobid builtins do not cause a job to be remembered for longer
like expanding $! does.

PR: bin/55346

sh: Pass through SIGINT from a child if interactive and job control
is enabled.

This already worked if without job control.

In either case, this depends on it that a process that terminates due to
SIGINT exits on it (so not with status 1, or worse, 0).

Example:
sleep 5; echo continued
This does not print "continued" any more if sleep is aborted via ctrl+c.

MFC after: 1 month

sh: Reap any zombies before forking for a background command.

This prevents accumulating huge amounts of zombies if a script executes
many background commands but no external commands or subshells.

Note that zombies will not be reaped during long calculations (within
the shell process) or read builtins, but those actions do not create
more zombies.

The terminated background commands will also still be remembered by the
shell.

PR: bin/55346

sh: Various warning fixes (from WARNS=6 NO_WERROR=1):
- const
- initializations to silence -Wuninitialized (it was safe anyway)
- remove nested extern declarations
- rename "index" locals to "idx"

sh: Do not run callers' exception handlers in subshells.

Reset the exception handler in the child to main's.

This avoids inappropriate double cleanups or shell duplication when the
exception is caught, such as 'fc' and future 'command eval' and 'command .'.

sh: Some changes to stderr flushing:
* increase buffer size from 100 to 256 bytes
* remove implied flush from out2str(), in particular this avoids unnecessary
flushing in the middle of a -x tracing line
* rename dprintf() to out2fmt_flush(), make it flush out2 and use this
function in various places where flushing is desired after an error
message

Add the POSIX option -p to the jobs builtin command. It prints the PID of the
process leader for each job. Now the last specified option for the output
format (-l, -p or -s) wins, previously -s trumped -l.

PR: 99926
Submitted by: Ed Schouten and novel (patches modified by me)

Remove some white space at EOL.

o Now when SIG_IGN signal action for SIGCHLD reap zombies
automatically it is possible wait4(2) returns -1 and sets
errno = ECHILD if there were forked children. A user can
set such signal handler e.g. via ``trap "" 20'', see a PR
for the test case. Deal with this case and mark a job as
JOBDONE.

PR: bin/90334
Submitted by: bde
MFC after: 4 weeks

Print pointers with %p rather than casting them to long.

o Terminate an endless loop sh -T goes into in dowait() around waitproc().

XXX from Tor: "The shell can also go into a similar loop if the child was
killed by signal 127, since the shell would believe the child to have
only stopped (WIFSTOPPED() macro returns nonzero value). Disallowing
signals 127 and 128 will fix that problem." See kern/19402 for details.

PR: bin/66242
Submitted by: tegge
Analysis and testcase by: demon
MFC after: 3 weeks

Remove clause 3 from the UCB licenses.

OK'ed by: imp, core

Commit fix sent by Tor Egge <Tor.Egge@cvsup.no.freebsd.org>

Only use return value from system call if system call succeeded.

Tested with `make world` and some of my own scripts.

This should be MFCed soon. While /bin/sh is hard to test the fix is
obviously correct and can be assumed not to break something else
(famous last words...).

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

Changes following CScout analysis:

- Removed dead declarations
- Made objects that should have been declared as static, static.

The changes use STATIC instead of static, following the existing
convention in the rest of the code.

Approved by: schweikh (mentor)
MFC after: 2 weeks

Flush the output buffers before forking a child process to avoid
the child process writing data that the parent should have written.

PR: 50051
MFC after: 2 weeks

Ensure that the TTY file descriptor is greater than or equal to 10 so that
it doesn't interfere with the user's redirections.

PR: 47136
MFC after: 1 week

Make this compile with DEBUG defined now that WARNS=0 has been removed
from the Makefile:
- Print pointers with %p instead of %x.
- Include missing headers to get prototypes.

Noticed by: benno

When job control is disabled, never show the job id when reporting the
status of a background process that has terminated because of a signal.

Use the %t format modifier to print differences between
pointers. This fixes two format warnings on 64 bits
archs which are fatal now that WFORMAT=0 has been removed.

It doesn't fully fix the sh(1) build on 64 bits platforms
though, there is still some quad_t issues that need to be
fixed.

Tested on: i386, sparc64

Correct a usage of fnctl that could not be right and results in a
no-op. I assume it was meant that the close-on-exec flag be set here.

Don't show the process ID of background jobs that have terminated,
for consistency with ksh.

Avoid accessing the current job's process table in the child part of
forkshell() after it has been freed. This caused mysterious behaviour
when anything but the first command in a pipeline tried to access the
terminal when the `junk' malloc() option was enabled (which is the default).

Show job control ID, command text, etc. when foreground processes are
suspended. This is a followup to rev. 1.51.

MFC after: 1 week

Set opterr to zero to avoid duplicate warnings from getopt(3) for unknown
options.

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.

Avoid using ints or shorts to store process id's, use pid_t instead.
The pgrp member of struct job was declared as a short and could not store
every possible process group ID value, the rest of them were benign because
pid_t happens to be an int.

Make the message that is printed when the foreground process is terminated
by a signal the same as pdksh/bash/sh before rev. 1.34.

Don't assume the shell's controlling terminal is attached to file descriptor
2. Instead, open /dev/tty. This problem stopped commands in subshells from
being executed correctly if standard error was redirected.

PR: 36671
Obtained from: NetBSD (but simplified)

Remove support for the "old" tty driver by unifdef -UOLD_TTY_DRIVER;
many other parts of the shell are no longer compatible with this, and it
makes jobs.c quite cluttered with #ifdef's.

When growing the job table, don't relocate the jobmru pointer if it's NULL.

Print out commands with NTOFD/NFROMFD redirections that close the
descriptors (">&-" or similar) correctly in the jobs(1) command.

Consistently use FBSDID

Remove two unused variables.

Display job status correctly when a pipeline is suspended.

Describe finished jobs as "Done", not "Exit" (SUSv3)

Don't output `state' and `current' fields for processes that aren't
leaders in -l option to jobs(1).

Correct minor spacing problem in output of jobs -l for pipelines.

Support the remaining job ID formats required by SUSv3:
%+ (current job, same as %%),
%- (previous job),
%?str (job with "str" in its command name).

Add -s (output PID's only) and -l (show PID's) options to the jobs(1)
builtin. Modify the output format to match what SUSv3 requires.

#if JOBS around a job control-related statement to allow compilation with
job control disabled.

Break the code to display status info for one job out from showjobs() into
showjob(), use it inside dowait() to display status info for consistency,
and in a format closer to what the standard requires.

Move job to front of most recently used job list when bg'd or fg'd.

Instead of keeping just the jobid of the most recently bg'd or fg'd job,
keep a linked list of the jobs, most recently used first. This is required
to support the idea of `previous job', and to allow the jobs fg and bg
default to be correct according to POSIX.

Make the fg and bg commands give the output required by SUSv3.
fg outputs the name of the command, bg outputs the name of the command
and the job id.

Implement the -C (-o noclobber) option, which prevents existing regular
files from being overwritten by shell redirection.

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)
{
...

Fix child's SIGSTOP behaviour in scripts.

When a child is receiving SIGSTOP, eval continues with the next
command. While that is correct for the interactive case (Control-Z
and you get the prompt back), it is wrong for a shellscript, which
just continues with the next command, never again waiting for the
stopped child. Noted when childs from cronjobs were stopped, just to
make more processes (by wosch).

The fix is not to return from a job wait when the wait returned for a
stopped child while in non-interactive mode. This bahaviour seems to
be what bash2 and ksh implement. I tested for correct behaviour for
finnaly killing the child with and without forgrounding it first.
When not foregrouding before killing, the shell continues with the
script, which is what the other shells do as well.

Reviewed by: Silence on -current

Add `_PATH_DEVZERO'.
Use _PATH_* where where possible.

Implement the <> redirection operator.

Fix warnings, some of them serious because sh violated name
spaces reserved by the header files it includes.

mkinit.c still produces C code with redundant declarations, although
they are more harmless since they automatically derived from the right
places.

Include strerror(errno) in error messages after failed system calls.
Fix a warning.

$Id$ -> $FreeBSD$

Various spelling/formatting changes.

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

Next approach to make loops in interactive interruptable.

PR: bin/9173

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

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.

Back out my previous attempt to fix SIGINT/SIGTERM behaviour

Fix handling of SIGINT/SIGQUIT for foreground subprocesses. Most
urgent need is when you run sh around a program that intentionally
uses SIGQUIT/SIGINT for asynchronous events, i.e. $EDITOR started from
system(2), like many mailers do. This fixes PR bin/1206 and possibly
bin/4241.

The solution committed has been tested for a large number of possible
cases (see recent discussion on cvs-committers). I completed a make
world, made sure 'make world' is interruptable and used the changed
/bin/sh as a login shell all day, including job control and using
SIGQUIT-catching programs (to write this message :-).

PR: bin/1206
Reviewed by: discussion on cvs-commiters

Remove simultaneous include of <sys/param.h> and <sys/types.h>.
Reorder includes to be alphabetical some places since I already was in
here.

Make all status values an integral type and use
pid_t when referring to process IDs.

Make sh(1) less aware of the bit fields returned by wait by
using the WIF* macros in sys/wait.h.

PR: bin/3668
Submitted by: dholland@eecs.harvard.edu

Use the __unused attribute where warranted.

Nuke register keyword usage and #if -> #ifdef.

Obtained from: NetBSD

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.

Fix a problem that caused some foreground pipelines to die with:

tcsetpgrp failed, errno=1

Discovered and Reviewed by: joerg

Merge in NetBSD mods and -Wall cleaning.

Obtained from: NetBSD, me

Benign | --> || correction.

Fix for PR#1287. This makes sh behave sensibly in case statements in the
face of aliases. Note, bash doesn't do aliases while running scripts, but
"real" ksh does..

Also:
Reduce redundant .Nm macros in (unused) bltin/echo.1
nuke error2, it's hardly used.
More -Wall cleanups
dont do certain history operations if NO_HISTORY defined
handle quad_t's from resource limits

Submitted by: Steve Price <sprice@hiwaay.net> (minor tweaks by me)

Misc cleanups and fixes from Bruce:
- don't put \n on error() calls, error adds it already.
- don't prepend "ulimit" on error() calls in miscbltin.c.
- getopt typo on ulimit -p -> -u conversion
- get/setrlimit() calls were not being error checked

ulimit formatting cleanup from me, use same wording as bash on Bruce's
suggestion. Add ulimit arg to output on Joerg's suggestion.

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

Fix relocation of job table.

while { sleep 1 & wait; } do echo 1; done

corrupted the job table every 4th iteration.

Remove trailing whitespace.

Reviewed by: phk

Added $Id$

This commit was generated by cvs2svn to compensate for changes in r1556,
which included commits to RCS files with non-trunk default branches.

BSD 4.4 Lite bin Sources