CVS log for src/bin/sh/histedit.c

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Pull up following revision(s) (requested by kre in ticket #1860):

	bin/sh/histedit.c: revision 1.72

Fix a very old core dump causing bug found by RVP in the history code.

That is, truly very old - it is in rev 1.1 from 1994 (and so is probably
even older than that).

If one uses the (very rarely used)

	fc -s string=otherstring

builtin command, to rerun the previous command (or with additional args,
any other command) after replacing the first instance of "string" in that
command with "otherstring" and the resulting command line just happens to
be a length that is a multiple of the shell's memory allocation alignment
constant, then the \0 string terminator that is appended to the result
to mark its end stood a very small chance (in 1994 probably no chance at all,
but made considerably more likely in 1999 when other changes were made -
certain in the right circumstances) of being destroyed by other sh memory
allocation before the string was finished being used.

The fix (also suggested by RVP) is to make that \0 an actual part of
the allocated result string, rather than an extra byte tacked on the
end of it -- in itself, doing the latter is common in sh, and not at all
improper, sometimes even required, but only when the string as a string
will be consumed before more (shell) stack memory allocation is performed.

It 1994 it would have been.   Since 1999, it isn't.

The 1999 change is going to be undone in a later commit, but this one
is simpler to pull up to earlier releases, and probably the right thing
to do anyway, even if not strictly essential.

Pull up following revision(s) (requested by kre in ticket #774):

	bin/sh/histedit.c: revision 1.72

Fix a very old core dump causing bug found by RVP in the history code.

That is, truly very old - it is in rev 1.1 from 1994 (and so is probably
even older than that).

If one uses the (very rarely used)

	fc -s string=otherstring

builtin command, to rerun the previous command (or with additional args,
any other command) after replacing the first instance of "string" in that
command with "otherstring" and the resulting command line just happens to
be a length that is a multiple of the shell's memory allocation alignment
constant, then the \0 string terminator that is appended to the result
to mark its end stood a very small chance (in 1994 probably no chance at all,
but made considerably more likely in 1999 when other changes were made -
certain in the right circumstances) of being destroyed by other sh memory
allocation before the string was finished being used.

The fix (also suggested by RVP) is to make that \0 an actual part of
the allocated result string, rather than an extra byte tacked on the
end of it -- in itself, doing the latter is common in sh, and not at all
improper, sometimes even required, but only when the string as a string
will be consumed before more (shell) stack memory allocation is performed.

It 1994 it would have been.   Since 1999, it isn't.

The 1999 change is going to be undone in a later commit, but this one
is simpler to pull up to earlier releases, and probably the right thing
to do anyway, even if not strictly essential.

Revert a part of a change made on 1999-07-09 (in rev 1.21).

That change ("compile with WARNS = 2") added "const" qualifiers
in many places.

One of them, in this file, became a const char *, which needed to be
passed to sh function defined as taking a char * arg.  (evalstring()).

To do that safely (in 1999), a copy of the original string was made,
and that copy was passed to evalstring() instead of the original.
The copy is simply char *, and if something altered it, no-one would
care.   The original string (in some cases) must not be altered.

That was the cause of the bug fixed (a different way) in the
previous commit to this file.   To copy the string, space needed
to be allocated, and when that was done, if the string was just
(the right length, its terminating \0 (which previously was stored
outside the string itself) and if the current shell stack memory block
was big enough that a new one wasn't needed, the \0 would be trampled
(then the strcpy() would become overwriting, and havoc result).

Now evalstring() has been updated to take a const char *, and
the string passed to it truly is treated as const data (nothing
ever attempts to alter it) so making a copy of the string isn't
needed, and we can go back to the way the code used to be, pre-1999.

That is, modulo other unrelated changes (or one change actually)
that has been made since, which has nothing to do with the issues here.

The change made in the previous revision could be undone, but won't
be, as it is logically the right thing to do.

NFCI.

Fix a very old core dump causing bug found by RVP in the history code.
That is, truly very old - it is in rev 1.1 from 1994 (and so is probably
even older than that).

If one uses the (very rarely used)
	fc -s string=otherstring
builtin command, to rerun the previous command (or with additional args,
any other command) after replacing the first instance of "string" in that
command with "otherstring" and the resulting command line just happens to
be a length that is a multiple of the shell's memory allocation alignment
constant, then the \0 string terminator that is appended to the result
to mark its end stood a very small chance (in 1994 probably no chance at all,
but made considerably more likely in 1999 when other changes were made -
certain in the right circumstances) of being destroyed by other sh memory
allocation before the string was finished being used.

The fix (also suggested by RVP) is to make that \0 an actual part of
the allocated result string, rather than an extra byte tacked on the
end of it -- in itself, doing the latter is common in sh, and not at all
improper, sometimes even required, but only when the string as a string
will be consumed before more (shell) stack memory allocation is performed.
It 1994 it would have been.   Since 1999, it isn't.

The 1999 change is going to be undone in a later commit, but this one
is simpler to pull up to earlier releases, and probably the right thing
to do anyway, even if not strictly essential.

XXX pullup -9, -10 (and everything back to 1.5 - it looks as if 1.4 is OK).

Pull up following revision(s) (requested by kre in ticket #1856):

	bin/sh/histedit.c: revision 1.68

Ignore non-numeric values for HISTSIZE

This is a temporary change (which can be pulled up to -9 and -10)
to avoid having

	HISTSIZE=foo /bin/sh

cause sh to fail to start.

A better change, but one requiring far more code changes, so that
bad HISTSIZE is ignored, only when read from the environment, but
will be an error otherwise, will come later.

Pull up following revision(s) (requested by kre in ticket #761):

	bin/sh/histedit.c: revision 1.68

Ignore non-numeric values for HISTSIZE

This is a temporary change (which can be pulled up to -9 and -10)
to avoid having

	HISTSIZE=foo /bin/sh

cause sh to fail to start.

A better change, but one requiring far more code changes, so that
bad HISTSIZE is ignored, only when read from the environment, but
will be an error otherwise, will come later.

Implement the HISTFILE and HISTAPPEND variables.

See the (newly updated) sh(1) for details.
Also add the -z option to fc (clear history).

None of this exists in SMALL shells.

Improve safety in var imports from the environment.

Add a new var flag VUNSAFE - set on all vars imported from the environment.

Add setvareqsafe() (which is to setvareq() as setvarsafe() is to setvar())
and use that instead of setvareq() when processing the environment, so
errors don't cause the shell to abort.  Use VUNSAFE in that call.

Add flags arguments to all var callback functions which are used when setting
variables, and pass the flags given to the setvar*() functions to those
functions, so they can act differently in different situations (if desired).
Most of them just ignore the flags.

When unsetting a variable, call setvar() to clear things (and call the
callback function) both when the variable had a value which needs to be freed,
and when unsetting a variable which wasn't unset previously, so the VUNSET
flag can be seen by that callback func.

When setting HISTSIZE, use the flags passed to determine whether to ignore
bad values (if VUNSAFE) or treat them as an error.  This replaces the
earlier temporary hack to always ignore bad data there (histedit.c 1.68).

Miscellaneous associated minor changes.

These changes should largely be invisible in normal use.

Don't emit a user causable "internal error" message.

Non-numeric args to "fc" simply fail to find the string
in an empty history buffer, as they might in a non-empty
history, and generate a reasonable error message.

But normally, as numeric args to the "fc" utility are trimmed
to the bounds of the contents of the history buffer, it
is impossible for them to fail to find an entry, as at the
very least the "fc" command itself should be there.

Hence "sh" claimed such a thing was an "internal error".

But it is possible to run fc commands, not entered from
stdin, and so not eligible for the history buffer, before
any interactive commands are entered.   In such a case
the history buffer will be empty, which "sh" has been
reporting as an "internal error".   It isn't.
Generate a more meaningful (and less scary) message instead.

No pullups planned - the code has been like this for a
very long time, and no-one ever noticed, as it would be
very (VERY) unusual for the "fc" utility to be invoked
at a time when the history buffer is active & empty, given
the way the code currently exists (unlikely, not impossible).

This change is more in preparation for future possible
changes which would make this error easier to encounter.

Ignore non-numeric values for HISTSIZE

This is a temporary change (which can be pulled up to -9 and -10)
to avoid having
	HISTSIZE=foo /bin/sh
cause sh to fail to start.

A better change, but one requiring far more code changes, so that
bad HISTSIZE is ignored, only when read from the environment, but
will be an error otherwise, will come later.

XXX pullup -9, -10

General source cleanup, whitespace, KNF, 80-col police, ...

No executable binary change intended (certainly NFCI).
Some debugging info will change as line numbers have altered.

The great shell trailing whitespace cleanup of 2023...
Inspired by private e-mail comments from mouse@

NFCI.

Add debugging trace points for history and the editline interface.
NFC for any normal shell (not compiled with debugging (sh DEBUG) enabled.

We have had a defined debug mode for this for years, but since I have
not often played in this arena, never used it.  Until recently (relatively).
This (or a small part of it) played a part in discovering the fc -e
bug cause.   I have had it in my tree a while now - recent changes
kept causing merge conflicts (all because I hadn't bothered to commit
this), so I think now is the time...

sh(1): revert previous because it interferes with custom user bindings

sh(1): Allow an explicit set -o vi or set -o emacs to override ~/.editrc

sh(1): Assign the tab completion key binding last so a user having
"bind -v" or "bind -e" in ~/.editrc doesn't cause tab completion
to no longer function.

Pull up following revision(s) (requested by kre in ticket #1736):

	bin/sh/histedit.c: revision 1.60

After (a few days short of) 21 years, revert 1.25, which did nothing except
make the -e option to "fc" fail to work (the commit message was about some
other changes entirely, so I an only assume this was committed by mistake).

It says a lot about the use of the fc command that no-one noticed that
this did not work properly for all this time.

Internally in sh, it is possible for built in commands to use either
getopt(3) (from libc) or the much simpler internal shell nextopt() routine
for option (flag) parsing.    However it makes no sense to use getopt()
and then access a global variable set only by nextopt() instead of the
one getopt() sets (which is what the code had used previously, forever).

Use the correct variable again.

XXX pullup -9 -8  (-7 -6 -5 ...)

Pull up following revision(s) (requested by kre in ticket #1429):

	bin/sh/histedit.c: revision 1.60

After (a few days short of) 21 years, revert 1.25, which did nothing except
make the -e option to "fc" fail to work (the commit message was about some
other changes entirely, so I an only assume this was committed by mistake).

It says a lot about the use of the fc command that no-one noticed that
this did not work properly for all this time.

Internally in sh, it is possible for built in commands to use either
getopt(3) (from libc) or the much simpler internal shell nextopt() routine
for option (flag) parsing.    However it makes no sense to use getopt()
and then access a global variable set only by nextopt() instead of the
one getopt() sets (which is what the code had used previously, forever).

Use the correct variable again.

XXX pullup -9 -8  (-7 -6 -5 ...)

sh: fix typo in comment

After (a few days short of) 21 years, revert 1.25, which did nothing except
make the -e option to "fc" fail to work (the commit message was about some
other changes entirely, so I an only assume this was committed by mistake).

It says a lot about the use of the fc command that no-one noticed that
this did not work properly for all this time.

Internally in sh, it is possible for built in commands to use either
getopt(3) (from libc) or the much simpler internal shell nextopt() routine
for option (flag) parsing.    However it makes no sense to use getopt()
and then access a global variable set only by nextopt() instead of the
one getopt() sets (which is what the code had used previously, forever).

Use the correct variable again.

XXX pullup -9 -8  (-7 -6 -5 ...)

When we initialize libedit (editline) always call ourselves "sh" no
matter what $0 is (or is not) set to.   This means that editrc(5)
lines that start "sh:" are used (in addition to those with no prefix,
which will usually be most of them), regardless of the name or manner in
which we were invoked.

OK christos@

Add some comments explaining accesses to the environment via
getenv()/setenv()/unsetenv() which manipulate the envornoment
the shell was passed at entry.

These are a little odd in sh as that environment is copied into
the shell's internal variable data struct at shell startup, and
normally never accessed after that - in builtin commands (test.
printf, ...) getenv() is #defined to become an internal sh lookup
function instead, so even those never use the startup environment).

NFCI

Quote the filenames like before

- Add command completion (from FreeBSD)
- Use EL_SAFEREAD

Ooops, restore accidently removed files from merge mishap

Sync with HEAD

Sync with HEAD

Remove a function prototype which was added to <histedit.h> in 2005.
I think we can trust it to be stable by now, and doin't need the dup.

INTON / INTOFF audit and cleanup.

No visible differences expected - there is a remote chance that
some internal lossage may no longer occur in interactive shells
that receive SIGINT (untrapped) at inopportune times, but you would
have had to have been very unlucky to have ever suffered from that.

Pull up following revision(s) (requested by kre in ticket #988):

	bin/sh/parser.c: revision 1.147
	bin/sh/var.c: revision 1.70
	bin/sh/mystring.c: revision 1.18
	bin/sh/options.c: revision 1.53
	bin/sh/histedit.c: revision 1.53

Remove atoi()

Mostly use number() (no longer implemented using atoi()) when an
unsigned integer is required, but use strtoXXX() when a conversion
is wanted, without the possibility or error (like setting OPTIND
and RANDOM).   Always init OPTIND to 1 when sh starts (overriding
anything in environ.)

Sync with HEAD

Remove atoi()

Mostly use number() (no longer implemented using atoi()) when an
unsigned integer is required, but use strtoXXX() when a conversion
is wanted, without the possibility or error (like setting OPTIND
and RANDOM).   Always init OPTIND to 1 when sh starts (overriding
anything in environ.)

Pull up following revision(s) (requested by kre in ticket #103):
	bin/kill/kill.c: 1.28
	bin/sh/Makefile: 1.111-1.113
	bin/sh/arith_token.c: 1.5
	bin/sh/arith_tokens.h: 1.2
	bin/sh/arithmetic.c: 1.3
	bin/sh/arithmetic.h: 1.2
	bin/sh/bltin/bltin.h: 1.15
	bin/sh/cd.c: 1.49-1.50
	bin/sh/error.c: 1.40
	bin/sh/eval.c: 1.142-1.151
	bin/sh/exec.c: 1.49-1.51
	bin/sh/exec.h: 1.26
	bin/sh/expand.c: 1.113-1.119
	bin/sh/expand.h: 1.23
	bin/sh/histedit.c: 1.49-1.52
	bin/sh/input.c: 1.57-1.60
	bin/sh/input.h: 1.19-1.20
	bin/sh/jobs.c: 1.86-1.87
	bin/sh/main.c: 1.71-1.72
	bin/sh/memalloc.c: 1.30
	bin/sh/memalloc.h: 1.17
	bin/sh/mknodenames.sh: 1.4
	bin/sh/mkoptions.sh: 1.3-1.4
	bin/sh/myhistedit.h: 1.12-1.13
	bin/sh/nodetypes: 1.16-1.18
	bin/sh/option.list: 1.3-1.5
	bin/sh/parser.c: 1.133-1.141
	bin/sh/parser.h: 1.22-1.23
	bin/sh/redir.c: 1.58
	bin/sh/redir.h: 1.24
	bin/sh/sh.1: 1.149-1.159
	bin/sh/shell.h: 1.24
	bin/sh/show.c: 1.43-1.47
	bin/sh/show.h: 1.11
	bin/sh/syntax.c: 1.4
	bin/sh/syntax.h: 1.8
	bin/sh/trap.c: 1.41
	bin/sh/var.c: 1.56-1.65
	bin/sh/var.h: 1.29-1.35
An initial attempt at implementing LINENO to meet the specs.
Aside from one problem (not too hard to fix if it was ever needed) this version
does about as well as most other shell implementations when expanding
$((LINENO)) and better for ${LINENO} as it retains the "LINENO hack" for the
latter, and that is very accurate.
Unfortunately that means that ${LINENO} and $((LINENO)) do not always produce
the same value when used on the same line (a defect that other shells do not
share - aside from the FreeBSD sh as it is today, where only the LINENO hack
exists and so (like for us before this commit) $((LINENO)) is always either
0, or at least whatever value was last set, perhaps by
	LINENO=${LINENO}
which does actually work ... for that one line...)
This could be corrected by simply removing the LINENO hack (look for the string
LINENO in parser.c) in which case ${LINENO} and $((LINENO)) would give the
same (not perfectly accurate) values, as do most other shells.
POSIX requires that LINENO be set before each command, and this implementation
does that fairly literally - except that we only bother before the commands
which actually expand words (for, case and simple commands).   Unfortunately
this forgot that expansions also occur in redirects, and the other compound
commands can also have redirects, so if a redirect on one of the other compound
commands wants to use the value of $((LINENO)) as a part of a generated file
name, then it will get an incorrect value.  This is the "one problem" above.
(Because the LINENO hack is still enabled, using ${LINENO} works.)
This could be fixed, but as this version of the LINENO implementation is just
for reference purposes (it will be superseded within minutes by a better one)
I won't bother.  However should anyone else decide that this is a better choice
(it is probably a smaller implementation, in terms of code & data space then
the replacement, but also I would expect, slower, and definitely less accurate)
this defect is something to bear in mind, and fix.
This version retains the *BSD historical practice that line numbers in functions
(all functions) count from 1 from the start of the function, and elsewhere,
start from 1 from where the shell started reading the input file/stream in
question.  In an "eval" expression the line number starts at the line of the
"eval" (and then increases if the input is a multi-line string).
Note: this version is not documented (beyond as much as LINENO was before)
hence this slightly longer than usual commit message.
A better LINENO implementation.   This version deletes (well, #if 0's out)
the LINENO hack, and uses the LINENO var for both ${LINENO} and $((LINENO)).
(Code to invert the LINENO hack when required, like when de-compiling the
execution tree to provide the "jobs" command strings, is still included,
that can be deleted when the LINENO hack is completely removed - look for
refs to VSLINENO throughout the code.  The var funclinno in parser.c can
also be removed, it is used only for the LINENO hack.)
This version produces accurate results: $((LINENO)) was made as accurate
as the LINENO hack made ${LINENO} which is very good.  That's why the
LINENO hack is not yet completely removed, so it can be easily re-enabled.
If you can tell the difference when it is in use, or not in use, then
something has broken (or I managed to miss a case somewhere.)
The way that LINENO works is documented in its own (new) section in the
man page, so nothing more about that, or the new options, etc, here.
This version introduces the possibility of having a "reference" function
associated with a variable, which gets called whenever the value of the
variable is required (that's what implements LINENO).  There is just
one function pointer however, so any particular variable gets at most
one of the set function (as used for PATH, etc) or the reference function.
The VFUNCREF bit in the var flags indicates which func the variable in
question uses (if any - the func ptr, as before, can be NULL).
I would not call the results of this perfect yet, but it is close.
Unbreak (at least) i386 build .... I have no idea why this built for me on
amd64 (problem was missing prototype for snprintf witout <stdio.h>)
While here, add some (DEBUG mode only) tracing that proved useful in
solving another problem.
Set the line number before expanding args, not after.   As the line_number
would have usually been set earlier, this change is mostly an effective
no-op, but it is better this way (just in case) - not observed to have
caused any problems.
Undo some over agressive fixes for a (pre-commit) bug that did not
need these changes to be fixed - and these cause problems in another
absurd use case.   Either of these issues is unlikely to be seen by
anyone who isn't an idiot masochist...
PR bin/52280
removescapes_nl in expari() even when not quoted,
CRTNONL's appear regardless of quoting (unlike CTLESC).
New sentence, new line. Whitespace.
Improve the (new) LINENO section, markup changes (with thanks to wiz@ for
assistace) and some better wording in a few placed.
I am an idiot...  revert the previous unintended commit.
Remove some left over baggage from the LINENO v1 implementation that
didn't get removed with v2, and should have.   This would have had
(I think, without having tested it) one very minor effect on the way
LINENO worked in the v2 implementation, but my guess is it would have
taken a long time before anyone noticed...
Correct spelling in comments of DEBUG only code...
(Perhaps) temporary fix to pkgtools (cwrappers) build (configure).
Expanding  `` containing \ \n sequences looks to have been giving
problems.   I don't think this is the correct fix, but it will do
no worse harm than (perhaps) incorrectly calculating LINENO in this
kind of (rare) circumstance.   I'll look and see if there should be
a better fix later.
s/volatile/const/ -- wonderful how opposites attract like this.
NFC (normal use) - DEBUG only change, when showing empty arg list don't
omit terminating \n.
Free stack memory in a couple of obscure cases where it wasn't
being done (one in probably dead code that is never compiled, the other
in a very rare error case.)   Since it is stack memory it wasn't lost
in any case, just held longer than needed.
Many internal memory management type fixes.
PR bin/52302   (core dump with interactive shell, here doc and error
on same line) is fixed.   (An old bug.)
echo "$( echo x; for a in $( seq 1000 ); do printf '%s\n'; done; echo y )"
consistently prints 1002 lines (x, 1000 empty ones, then y) as it should
(And you don't want to know what it did before, or why.) (Another old one.)
(Recently added) Problems with ~ expansion fixed (mem management related).
Proper fix for the cwrappers configure problem (which includes the quick
fix that was done earlier, but extends upon that to be correct). (This was
another newly added problem.)
And the really devious (and rare) old bug - if STACKSTRNUL() needs to
allocate a new buffer in which to store the \0, calculate the size of
the string space remaining correctly, unlike when SPUTC() grows the
buffer, there is no actual data being stored in the STACKSTRNUL()
case - the string space remaining was calculated as one byte too few.
That would be harmless, unless the next buffer also filled, in which
case it was assumed that it was really full, not one byte less, meaning
one junk char (a nul, or anything) was being copied into the next (even
bigger buffer) corrupting the data.
Consistent use of stalloc() to allocate a new block of (stack) memory,
and grabstackstr() to claim a block of (stack) memory that had already
been occupied but not claimed as in use.  Since grabstackstr is implemented
as just a call to stalloc() this is a no-op change in practice, but makes
it much easier to comprehend what is really happening.  Previous code
sometimes used stalloc() when the use case was really for grabstackstr().
Change grabstackstr() to actually use the arg passed to it, instead of
(not much better than) guessing how much space to claim,
More care when using unstalloc()/ungrabstackstr() to return space, and in
particular when the stack must be returned to its previous state, rather than
just returning no-longer needed space, neither of those work.  They also don't
work properly if there have been (really, even might have been) any stack mem
allocations since the last stalloc()/grabstackstr().   (If we know there
cannot have been then the alloc/release sequence is kind of pointless.)
To work correctly in general we must use setstackmark()/popstackmark() so
do that when needed.  Have those also save/restore the top of stack string
space remaining.
	[Aside: for those reading this, the "stack" mentioned is not
	in any way related to the thing used for maintaining the C
	function call state, ie: the "stack segment" of the program,
	but the shell's internal memory management strategy.]
More comments to better explain what is happening in some cases.
Also cleaned up some hopelessly broken DEBUG mode data that were
recently added (no effect on anyone but the poor semi-human attempting
to make sense of it...).
User visible changes:
Proper counting of line numbers when a here document is delimited
by a multi-line end-delimiter, as in
	cat << 'REALLY
	END'
	here doc line 1
	here doc line 2
	REALLY
	END
(which is an obscure case, but nothing says should not work.)  The \n
in the end-delimiter of the here doc (the last one) was not incrementing
the line number, which from that point on in the script would be 1 too
low (or more, for end-delimiters with more than one \n in them.)
With tilde expansion:
	unset HOME; echo ~
changed to return getpwuid(getuid())->pw_home instead of failing (returning ~)
POSIX says this is unspecified, which makes it difficult for a script to
compensate for being run without HOME set (as in env -i sh script), so
while not able to be used portably, this seems like a useful extension
(and is implemented the same way by some other shells).
Further, with
	HOME=; printf %s ~
we now write nothing (which is required by POSIX - which requires ~ to
expand to the value of $HOME if it is set) previously if $HOME (in this
case) or a user's directory in the passwd file (for ~user) were a null
STRING, We failed the ~ expansion and left behind '~' or '~user'.
Changed the long name for the -L option from lineno_fn_relative
to local_lineno as the latter seemed to be marginally more popular,
and perhaps more importantly, is the same length as the peviously
existing quietprofile option, which means the man page indentation
for the list of options can return to (about) what it was before...
(That is, less indented, which means more data/line, which means less
lines of man page - a good thing!)
Cosmetic changes to variable flags - make their values more suited
to my delicate sensibilities...  (NFC).
Arrange not to barf (ever) if some turkey makes _ readonly.  Do this
by adding a VNOERROR flag that causes errors in var setting to be
ignored (intended use is only for internal shell var setting, like of "_").
(nb: invalid var name errors ignore this flag, but those should never
occur on a var set by the shell itself.)
From FreeBSD: don't simply discard memory if a variable is not set for
any reason (including because it is readonly) if the var's value had
been malloc'd.  Free it instead...
NFC - DEBUG changes, update this to new TRACE method.
KNF - white space and comment formatting.
NFC - DEBUG mode only change - convert this to the new TRACE() format.
NFC - DEBUG mode only change - complete a change made earlier (marking
the line number when included in the trace line tag to show whether it
comes from the parser, or the elsewhere as they tend to be quite different).
Initially only one case was changed, while I pondered whether I liked it
or not.  Now it is all done...   Also when there is a line tag at all,
always include the root/sub-shell indicator character, not only when the
pid is included.
NFC: DEBUG related comment change - catch up with reality.
NFC: DEBUG mode only change.  Fix botched cleanup of one TRACE().
"b" more forgiving when sorting options to allow reasonable (and intended)
flexibility in option.list format.   Changes nothing for current option.list.
Now that excessive use of STACKSTRNUL has served its purpose (well, accidental
purpose) in exposing the bug in its implementation, go back to not using
it when not needed for DEBUG TRACE purposes.   This change should have no
practical effect on either a DEBUG shell (where the STACKSTRNUL() calls
remain) or a non DEBUG shell where they are not needed.
Correct the initial line number used for processing -c arg strings.
(It was inheriting the value from end of profile file processing) - I didn't
notice before as I usually test with empty or no profile files to avoid
complications.   Trivial change which should have very limited impact.
Fix from FreeBSD (applied there in July 2008...)
Don't dump core with input like sh -c 'x=; echo >&$x' - that is where
the word after a >& or <& redirect expands to nothing at all.
Another fix from FreeBSD (this one from April 2009).
When processing a string (as in eval, trap, or sh -c) don't allow
trailing \n's to destroy the exit status of the last command executed.
That is:
	sh -c 'false
	'
	echo $?
should produce 1, not 0.
It is amazing what nonsense appears to work sometimes... (all my nonsense too!)
Two bugs here, one benign because of the way the script is used.
The other hidden by NetBSD's sort being stable, and the data not really
requiring sorting at all...
So as it happens these fixes change nothing, but they are needed anyway.
(The contents of the generated file are only used in DEBUG shells, so
this is really even less important than it seems.)
Another ancient (highly improbable) bug bites the dust.   This one
caused by incorrect macro usage (ie: using the wrong one) which has
been in the sources since version 1.1 (ie: forever).
Like the previous (STACKSTRNUL) bug, the probability of this one
actually occurring has been infinitesimal but the LINENO code increases
that to infinitesimal and a smidgen... (or a few, depending upon usage).
Still, apparently that was enough, Kamil Rytarowski discovered that the
zsh configure script (damn competition!) managed to trigger this problem.
source .editrc after we initialize so that commands persist!
Make arg parsing in kill POSIX compatible with POSIX (XBD 2.12) by
parsing the way getopt(3) would, if only it could handle the (required)
-signumber and -signame options.  This adds two "features" to kill,
-ssigname and -lstatus now work (ie: one word with all of the '-', the
option letter, and its value) and "--" also now works (kill -- -pid1 pid2
will not attempt to send the pid1 signal to pid2, but rather SIGTERM
to the pid1 process group and pid2).  It is still the case that (apart
from --) at most 1 option is permitted (-l, -s, -signame, or -signumber.)
Note that we now have an ambiguity, -sname might mean "-s name" or
send the signal "sname" - if one of those turns out to be valid, that
will be accepted, otherwise the error message will indicate that "sname"
is not a valid signal name, not that "name" is not.   Keeping the "-s"
and signal name as separate words avoids this issue.
Also caution: should someone be weird enough to define a new signal
name (as in the part after SIG) which is almost the same name as an
existing name that starts with 'S' by adding an extra 'S' prepended
(eg: adding a SIGSSYS) then the ambiguity problem becomes much worse.
In that case "kill -ssys" will be resolved in favour of the "-s"
flag being used (the more modern syntax) and would send a SIGSYS, rather
that a SIGSSYS.    So don't do that.
While here, switch to using signalname(3) (bye bye NSIG, et. al.), add
some constipation, and show a little pride in formatting the signal names
for "kill -l" (and in the usage when appropriate -- same routine.)   Respect
COLUMNS (POSIX XBD 8.3) as primary specification of the width (terminal width,
not number of columns to print) for kill -l, a very small value for COLUMNS
will cause kill -l output to list signals one per line, a very large
value will cause them all to be listed on one line.) (eg: "COLUMNS=1 kill -l")
TODO: the signal printing for "trap -l" and that for "kill -l"
should be switched to use a common routine (for the sh builtin versions.)
All changes of relevance here are to bin/kill - the (minor) changes to bin/sh
are only to properly expose the builtin version of getenv(3) so the builtin
version of kill can use it (ie: make its prototype available.)
Properly support EDITRC - use it as (naming) the file when setting
up libedit, and re-do the config whenever EDITRC is set.
Get rid of workarounds for ancient groff html backend.
Simplify macro usage.
Make one example more like a real world possibility (it still isn't, but
is closer) - though the actual content is irrelevant to the point being made.
Add literal prompt support this allows one to do:
CA="$(printf '\1')"
PS1="${CA}$(tput bold)${CA}\$${CA}$(tput sgr0)${CA} "
Now libedit supports embedded mode switch sequence, improve sh
support for them (adds PSlit variable to set the magic character).
NFC: DEBUG only change - provide an externally visible (to the DEBUG sh
internals) interface to one of the internal (private to trace code) functions
Include redirections in trace output from "set -x"
Implement PS1, PS2 and PS4 expansions (variable expansions, arithmetic
expansions, and if enabled by the promptcmds option, command substitutions.)
Implement a bunch of new shell environment variables. many mostly useful
in prompts when expanded at prompt time, but all available for general use.
Many of the new ones are not available in SMALL shells (they work as normal
if assigned, but the shell does not set or use them - and there is no magic
in a SMALL shell (usually for install media.))
Omnibus manual update for prompt expansions and new variables.  Throw in
some random cleanups as a bonus.
Correct a markup typo (why did I not see this before the prev commit??)
Sort options (our default is 0..9AaBbZz).
Fix markup problems and a typo.
Make $- list flags in the same order they appear in sh(1)
Do a better job of detecting the error in pkgsrc/devel/libbson-1.6.3's
configure script, ie: $(( which is intended to be a sub-shell in a
command substitution, but is an arith subst instead, it needs to be
written $( ( to do as intended.   Instead of just blindly carrying on to
find the missing )) somewhere, anywhere, give up as soon as we have seen
an unbalanced ')' that isn't immediately followed by another ')' which
in a valid arith subst it always would be.
While here, there has been a comment in the code for quite a while noting a
difference in the standard between the text descr & grammar when it comes to
the syntax of case statements.   Add more comments to explain why parsing it
as we do is in fact definitely the correct way (ie: the grammar wins arguments
like this...).
DEBUG and white space changes only.   Convert TRACE() calls for DEBUg mode
to the new style.   NFC (when not debugging sh).
Mostly DEBUG and white space changes.   Convert DEEBUG TRACE() calls to
the new format.   Also #if 0 a function definition that is used nowhere.
While here, change the function of pushfile() slightly - it now sets
the buf pointer in the top (new) input descriptor to NULL, instead of
simply leaving it - code that needs a buffer always (before and after)
must malloc() one and assign it after the call.  But code which does not
(which will be reading from a string or similar) now does not have to
explicitly set it to NULL (cleaner interface.)   NFC intended (or observed.)
DEBUG changes: convert DEBUG TRACE() calls to new format.
ALso, cause exec failures to always cause the shell to exit with
status 126 or 127, whatever the cause.  127 is intended for lookup
failures (and is used that way), 126 is used for anything else that
goes wrong (as in several other shells.)  We no longer use 2 (more easily
confused with an exit status of the command exec'd) for shell exec failures.
DEBUG only changes.  Convert the TRACE() calls in the remaining files
that still used it to the new format.   NFC.
Fix a reference after free (and consequent nonsense diagnostic for
attempts to set readonly variables) I added in 1.60 by incompletely
copying the FreeBSD fix for the lost memory issue.

Now libedit supports embedded mode switch sequence, improve sh
support for them (adds PSlit variable to set the magic character).

Add literal prompt support this allows one to do:
CA="$(printf '\1')"
PS1="${CA}$(tput bold)${CA}\$${CA}$(tput sgr0)${CA} "

Properly support EDITRC - use it as (naming) the file when setting
up libedit, and re-do the config whenever EDITRC is set.

source .editrc after we initialize so that commands persist!

Sprinkle volatile for gcc 5!

Rebase to HEAD as of a few days ago.

Rebase.

Adjust to the new alias text libedit API.

sync with head.

for a reference, the tree before this commit was tagged
as yamt-pagecache-tag8.

this commit was splitted into small chunks to avoid
a limitation of cvs.  ("Protocol error: too many arguments")

don't use sprintf

sync with head

Use C89 function definitions

Move the savehandler assignment before setjmp() to avoid triggering
warnings about use before initialization with clang.

Catchup with rmind-uvmplock merge.

PR/45069: Henning Petersen: Use prototypes from builtins.h .

Call el_source before initializing sh-specific editline properties (i.e.
the editor type and the tab completion binding).

This allows tab completion to work when a user has an ~/.editrc file.

Addresses PR bin/43404.

sync with HEAD

Set unique mode for the history, so that repeating a command doesn't
spam the history.

Pull up following revision(s) (requested by mjf in ticket #1689):
	bin/sh/histedit.c: revision 1.38
Make the -s flag of fc work correctly. Ensure that only one command
is specified and ensure that we break out of the loop after executing it.
With the previous code, because the re-executed command was added to the
history, it would think that it still had to execute it, leading to
an infinite loop.

sprinkle volatile.

quell GCC 4.1 uninitialised variable warnings.

XXX: we should audit the tree for which old ones are no longer needed
after getting the older compilers out of the tree..

Make the -s flag of fc work correctly. Ensure that only one command is specified
and ensure that we break out of the loop after executing it.
With the previous code, because the re-executed command was added to the
history, it would think that it still had to execute it, leading to an infinite
loop.

The last thing which differs from ksh is that we get the "fc -s " command into
the history, but this is actually rather a feature in my humble opinion.

To test:
$ echo hello
$ fc -s ec
<infinite loop or correct behaviour>

Only do certain actions when we are trully interactive, not just when we
are connected to a tty:
	1. enable editor
	2. print directory on directory change.
	3. print job messages

Only add the function when we initialize. Restore the binding of tab to
ed-insert if tabcomplete is cleared.

If 'set -o tabcomplete' it set, then bind <tab> to the libedit filename
completion function.
Note that the libedit code will probably want fine-tuning!
While editing the man page, add a note that non-whitespace IFS chars are
terminators and can generate null arguments.

skip a leading `-' on the arg0 name when calling el_init()

Let libedit handle signals so we resize properly. I might change my mind
later on that.

Ensure that $TERM is set in the real environment before calling el_init(3)
when executing "set -o (emacs|vi)".   Fixes [bin/23175] from me.

Move UCB-licensed code from 4-clause to 3-clause licence.

Patches provided by Joel Baker in PR 22249, verified by myself.

use bounded string op

ANSIify.

Add new builtin 'inputrc' which allows keybindings to be redefined
for the current shell.  From Arne H Juul in PR#10097.

Fixes from David Laight:
- ansification
- format of output of jobs command (etc)
- job identiers %+, %- etc
- $? and $(...)
- correct quoting of output of set, export -p and readonly -p
- differentiation between nornal and 'posix special' builtins
- correct behaviour (posix) for errors on builtins and special builtins
- builtin printf and kill
- set -o debug (if compiled with DEBUG)
- cd src obj (as ksh - too useful to do without)
- unset -e name, remove non-readonly variable from export list.
  (so I could unset -e PS1 before running the test shell...)

get rid of sp completely, we were free-ing a bogus pointer; found by simonb.

remove redundant declarations and nexted externs.

Call el_source() to use .editrc.

Don't declare 'extern opt*' getopt variables.

Fix bin/9184, bin/9194, bin/9265, bin/9266
Exitcode and negation problems (From Martin Husemann)

compile with WARNS = 2

Be more retentive about use of NOTREACHED and noreturn.

fix bug where if moving in history during a multi-line event, the
append to history event would end up in the last event where the history
was moved to instead of the multi-line event; reported by Mycroft

Sync with trunk, per request of christos.

Change a few things to reference /usr/include/paths.h instead of local
references. Fixing the default PATH is a bit more effort.

Pull rev 1.17 up from trunk (cjs)

Make this compile with -DSMALL and warnings on.

PR/4257: Jaromir Dolecek: Update for libedit interface change.

getopt returns -1 not EOF

Fix compiler warnings.

Track $TERM and call the appropriate editline(3) routine to update the
terminal type.

NO_HISTORY->SMALL

Fix problems with -DNO_HISTORY

Update /bin/sh from trunk per request of Christos Zoulas.  Fixes
many bugs.

PR/2808: Remove extraneous newlines from error routines (from FreeBSD)

change sethistsize() to take the history size as an argument so it can
be used directly by the new variable callback functions.

Merge in my changes from vangogh, and fix the x=`false`; echo $? == 0
bug.

1. Don't core dump on 'fc -l' (From Gerard J van der Grinten)
2. PATH=xxx ls, does the PATH assignment first and then tries to find ls in xxx
3. VAR=xxx exec ls, does the variable assignment.

convert to new RCS id conventions.

clean up further.  more patches from Jim Jegers

from James Jegers <jimj@miller.cs.uwm.edu>: quiet -Wall, and squelch
some of the worst style errors.

Add RCS ids.

Include appropriate header files to bring function prototypes into scope.

44lite code

Initial revision