Remove an end of file trailing blank line that served no purpose.

NFCI

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

NFCI.

fix various typos in comments, documentation and messages.

fix various typos in comments and output/log messages.

Use a type-correct end marker for strstrcat() rather than NULL, as
for a function with unknown number & types of args, the compiler isn't
able to automatically convert to the correct type. Issue pointed out
in off list e-mail by Rolland Illig ... Thanks.

The first arg (pointer to where to put length of result) is of a known
type, so doesn't have the same issue - we can keep using NULL for that
one when the length isn't needed.

Also, make sure to return a correctly null terminated null string in
the (absurd) case that there are no non-null args to strstrcat() (though
there are much better ways to generate "" on the stack). Since there is
currently just one call in the code, and it has real string args, this
isn't an issue for now, but who knows, some day.

NFCI - if there is any real change, then it is a change that is required.

XXX pullup -9 (together with the previous changes)

PR bin/56464

After almost 30 years, finally do the right thing and read $HOME/.profile
rather than .profile in the initial directory (it was that way in version
1.1 ...) All other ash descendants seem to have fixed this long ago.

While here, copy a feature from FreeBSD which allows "set +p" (if a
shell run by a setuid process with the -p flag is privileged) to reset
the privileges. Once done (the set +p) it cannot be undone (a later
set -p sets the 'p' flag, but that's all it does) - that just becomes a
one bit storage location.

We do this, as (also copying from FreeBSD, and because it is the right
thing to do) we don't run .profile in a privileged shell - FreeBSD run
/etc/suid_profile in that case (not a good name, it also applies to setgid
shells) but I see no real need for that, we run /etc/profile in any case,
anything that would go in /etc/suid_profile can just go in /etc/profile
instead (with suitable guards so the commands only run in priv'd shells).

One or two minor DEBUG mode changes (notably having priv'd shells identify
themselves in the DEBUG trace) and sh.1 changes with doc of the "set +p"
change, the effect that has on $PSc and a few other wording tweaks.

XXX pullup -9 (not -8, this isn't worth it for the short lifetime
that has left - if it took 28+ years for anyone to notice this, it
cannot be having all that much effect).

branches: 1.33.2;

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.

Fix (hopefully) the problem reported on current-users by Patrick Welche.
we had incorrect usage of setstackmark()/popstackmark()

There was an ancient idiom (imported from CSRG in 1993) where code
can do:
setstackmark(&smark); loop until whatever condition {
/* do lots of code */ popstackmark(&smark);
} popstackmark(&smark);

The 1st (inner) popstackmark() resets the stack, conserving memory,
The 2nd one is needed just in case the "whatever condition" was never
true, and the first one was never executed.

This is (was) safe as all popstackmark() did was reset the stack.
That could be done over and over again with no harm.

That is, until 2000 when a fix from FreeBSD for another problem was
imported. That connected all the stack marks as a list (so they can be
located). That caused the problem, as the idiom was not changed, now
there is this list of marks, and popstackmark() was removing an entry.

It rarely (never?) caused any problems as the idiom was rarely used
(the shell used to do loops like above, mostly, without the inner
popstackmark()). Further, the stack mark list is only ever used when
a memory block is realloc'd.

That is, until last weekend - with the recent set of changes.

Part of that copied code from FreeBSD introduced the idiom above
into more functions - functions used much more, and with a greater
possibility of stack marks being set on blocks that are realloc'd
and so cause the problem. In the FreeBSD code, they changed the idiom,
and always do a setstackmark() immediately after the inner popstackmark().
But not for reasons related to a list of stack marks, as in the
intervening period, FreeBSD deleted that, but for another reason.

We do not have their issue, and I did not believe that their
updated idiom was needed (I did some analysis of exactly this issue -
just missed the important part!), and just continued using the old one.
Hence Patrick's core dump....

The solution used here is to split popstackmark() into 2 halves,
popstackmark() continues to do what it has (recently) done,
but is now implemented as a call of (a new func) rststackmark()
which does all the original work of popstackmark - but not removing
the entry from the stack mark list (which remains in popstackmark()).
Then in the idiom above, the inner popstackmark() turns into a call of
rststackmark() so the stack is reset, but the stack mark list is
unchanged. Tail recursion elimination makes this essentially free.

Minor cleanups to growstackblock(). This should really change
nothing that matters, but might be slightly more robust/complete.

branches: 1.30.4; 1.30.6;
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'.

branches: 1.29.62;
Fix inconsistent definitions

branches: 1.28.22;
Move UCB-licensed code from 4-clause to 3-clause licence.

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

Support command -p, -v and -V as posix
Stop temporary PATH assigments messing up hash table
Fix sh -c -e "echo $0 $*" -a x (as posix)
(agreed by christos)

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...)

- it is wrong to put inton/intoff arount ckmalloc(), because the code
around it is the one that does this.
- whitespace fixes.

Rename ALIGN to SHELL_ALIGN and simplify macro so that it does not have side
effects, and add double to it, so that it aligns doubles correctly too. This
is just a workaround to fix the sparc64 problem where ALIGN() is now defined
in some include file to be 16 instead of 8. Thanks to martin for debugging this.

PR/11283: Hubert Feyrer: random memory corruption executing commands:
Fix from FreeBSD:

growstackblock() sometimes relocates a stack_block considered empty
without properly relocating stack marks referencing that block.
The first call to popstackmark() with the unrelocated stack mark
as argument then causes sh to abort.

Relocating the relevant stack marks seems to solve this problem.

The patch changes the semantics of popstackmark() somewhat. It can
only be called once after a call to setstackmark(), thus cmdloop() in
main.c needs an extra call to setstackmark().

Wrap malloc() calls with an INTOFF/INTON pair. Fixes PR 8414.

branches: 1.21.10;
Include our local includes after the system's ones.

branches: 1.20.2;
Fix compiler warnings.

kill 'register'

PR/2808: Remove trailing whitespace (from FreeBSD)

branches: 1.17.2;
Fix growstackblock() 'newlen' calculations:
(1) it needs to be ALIGNed for both halves of the 'if,' and
(2) if you're going to claim that you now have ALIGN(newlen)
bytes left, you should have actually allocated
ALIGN(newlen), rather than just 'newlen' bytes.

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

convert to new RCS id conventions.

Fix that last bug in a less expensive way.

take two: make grabstackstr() work correctly, in the face of strange filling.

Remove previous misguided change.

don't play fast and loose with memory block allcation. try to allocate
in more-round sizes, but realize that not everybody will fill them up
exactly.

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

Eliminate uses of some obsolete functions.

Add RCS ids.

use prototypes provided by header files instead of our own

Include appropriate header files to bring function prototypes into scope.

sync with 4.4lite

Add RCS identifiers.

changed "Id" to "Header" for rcsids

added rcs ids to all files

branches: 1.1.1;
Initial revision

fix various typos in comments, documentation and messages.

fix various typos in comments and output/log messages.

Use a type-correct end marker for strstrcat() rather than NULL, as
for a function with unknown number & types of args, the compiler isn't
able to automatically convert to the correct type. Issue pointed out
in off list e-mail by Rolland Illig ... Thanks.

The first arg (pointer to where to put length of result) is of a known
type, so doesn't have the same issue - we can keep using NULL for that
one when the length isn't needed.

Also, make sure to return a correctly null terminated null string in
the (absurd) case that there are no non-null args to strstrcat() (though
there are much better ways to generate "" on the stack). Since there is
currently just one call in the code, and it has real string args, this
isn't an issue for now, but who knows, some day.

NFCI - if there is any real change, then it is a change that is required.

XXX pullup -9 (together with the previous changes)

PR bin/56464

After almost 30 years, finally do the right thing and read $HOME/.profile
rather than .profile in the initial directory (it was that way in version
1.1 ...) All other ash descendants seem to have fixed this long ago.

While here, copy a feature from FreeBSD which allows "set +p" (if a
shell run by a setuid process with the -p flag is privileged) to reset
the privileges. Once done (the set +p) it cannot be undone (a later
set -p sets the 'p' flag, but that's all it does) - that just becomes a
one bit storage location.

We do this, as (also copying from FreeBSD, and because it is the right
thing to do) we don't run .profile in a privileged shell - FreeBSD run
/etc/suid_profile in that case (not a good name, it also applies to setgid
shells) but I see no real need for that, we run /etc/profile in any case,
anything that would go in /etc/suid_profile can just go in /etc/profile
instead (with suitable guards so the commands only run in priv'd shells).

One or two minor DEBUG mode changes (notably having priv'd shells identify
themselves in the DEBUG trace) and sh.1 changes with doc of the "set +p"
change, the effect that has on $PSc and a few other wording tweaks.

XXX pullup -9 (not -8, this isn't worth it for the short lifetime
that has left - if it took 28+ years for anyone to notice this, it
cannot be having all that much effect).

branches: 1.33.2;

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.

Fix (hopefully) the problem reported on current-users by Patrick Welche.
we had incorrect usage of setstackmark()/popstackmark()

There was an ancient idiom (imported from CSRG in 1993) where code
can do:
setstackmark(&smark); loop until whatever condition {
/* do lots of code */ popstackmark(&smark);
} popstackmark(&smark);

The 1st (inner) popstackmark() resets the stack, conserving memory,
The 2nd one is needed just in case the "whatever condition" was never
true, and the first one was never executed.

This is (was) safe as all popstackmark() did was reset the stack.
That could be done over and over again with no harm.

That is, until 2000 when a fix from FreeBSD for another problem was
imported. That connected all the stack marks as a list (so they can be
located). That caused the problem, as the idiom was not changed, now
there is this list of marks, and popstackmark() was removing an entry.

It rarely (never?) caused any problems as the idiom was rarely used
(the shell used to do loops like above, mostly, without the inner
popstackmark()). Further, the stack mark list is only ever used when
a memory block is realloc'd.

That is, until last weekend - with the recent set of changes.

Part of that copied code from FreeBSD introduced the idiom above
into more functions - functions used much more, and with a greater
possibility of stack marks being set on blocks that are realloc'd
and so cause the problem. In the FreeBSD code, they changed the idiom,
and always do a setstackmark() immediately after the inner popstackmark().
But not for reasons related to a list of stack marks, as in the
intervening period, FreeBSD deleted that, but for another reason.

We do not have their issue, and I did not believe that their
updated idiom was needed (I did some analysis of exactly this issue -
just missed the important part!), and just continued using the old one.
Hence Patrick's core dump....

The solution used here is to split popstackmark() into 2 halves,
popstackmark() continues to do what it has (recently) done,
but is now implemented as a call of (a new func) rststackmark()
which does all the original work of popstackmark - but not removing
the entry from the stack mark list (which remains in popstackmark()).
Then in the idiom above, the inner popstackmark() turns into a call of
rststackmark() so the stack is reset, but the stack mark list is
unchanged. Tail recursion elimination makes this essentially free.

Minor cleanups to growstackblock(). This should really change
nothing that matters, but might be slightly more robust/complete.

branches: 1.30.4; 1.30.6;
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'.

branches: 1.29.62;
Fix inconsistent definitions

branches: 1.28.22;
Move UCB-licensed code from 4-clause to 3-clause licence.

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

Support command -p, -v and -V as posix
Stop temporary PATH assigments messing up hash table
Fix sh -c -e "echo $0 $*" -a x (as posix)
(agreed by christos)

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...)

- it is wrong to put inton/intoff arount ckmalloc(), because the code
around it is the one that does this.
- whitespace fixes.

Rename ALIGN to SHELL_ALIGN and simplify macro so that it does not have side
effects, and add double to it, so that it aligns doubles correctly too. This
is just a workaround to fix the sparc64 problem where ALIGN() is now defined
in some include file to be 16 instead of 8. Thanks to martin for debugging this.

PR/11283: Hubert Feyrer: random memory corruption executing commands:
Fix from FreeBSD:

growstackblock() sometimes relocates a stack_block considered empty
without properly relocating stack marks referencing that block.
The first call to popstackmark() with the unrelocated stack mark
as argument then causes sh to abort.

Relocating the relevant stack marks seems to solve this problem.

The patch changes the semantics of popstackmark() somewhat. It can
only be called once after a call to setstackmark(), thus cmdloop() in
main.c needs an extra call to setstackmark().

Wrap malloc() calls with an INTOFF/INTON pair. Fixes PR 8414.

branches: 1.21.10;
Include our local includes after the system's ones.

branches: 1.20.2;
Fix compiler warnings.

kill 'register'

PR/2808: Remove trailing whitespace (from FreeBSD)

branches: 1.17.2;
Fix growstackblock() 'newlen' calculations:
(1) it needs to be ALIGNed for both halves of the 'if,' and
(2) if you're going to claim that you now have ALIGN(newlen)
bytes left, you should have actually allocated
ALIGN(newlen), rather than just 'newlen' bytes.

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

convert to new RCS id conventions.

Fix that last bug in a less expensive way.

take two: make grabstackstr() work correctly, in the face of strange filling.

Remove previous misguided change.

don't play fast and loose with memory block allcation. try to allocate
in more-round sizes, but realize that not everybody will fill them up
exactly.

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

Eliminate uses of some obsolete functions.

Add RCS ids.

use prototypes provided by header files instead of our own

Include appropriate header files to bring function prototypes into scope.

sync with 4.4lite

Add RCS identifiers.

changed "Id" to "Header" for rcsids

added rcs ids to all files

branches: 1.1.1;
Initial revision

fix various typos in comments and output/log messages.

Use a type-correct end marker for strstrcat() rather than NULL, as
for a function with unknown number & types of args, the compiler isn't
able to automatically convert to the correct type. Issue pointed out
in off list e-mail by Rolland Illig ... Thanks.

The first arg (pointer to where to put length of result) is of a known
type, so doesn't have the same issue - we can keep using NULL for that
one when the length isn't needed.

Also, make sure to return a correctly null terminated null string in
the (absurd) case that there are no non-null args to strstrcat() (though
there are much better ways to generate "" on the stack). Since there is
currently just one call in the code, and it has real string args, this
isn't an issue for now, but who knows, some day.

NFCI - if there is any real change, then it is a change that is required.

XXX pullup -9 (together with the previous changes)

PR bin/56464

After almost 30 years, finally do the right thing and read $HOME/.profile
rather than .profile in the initial directory (it was that way in version
1.1 ...) All other ash descendants seem to have fixed this long ago.

While here, copy a feature from FreeBSD which allows "set +p" (if a
shell run by a setuid process with the -p flag is privileged) to reset
the privileges. Once done (the set +p) it cannot be undone (a later
set -p sets the 'p' flag, but that's all it does) - that just becomes a
one bit storage location.

We do this, as (also copying from FreeBSD, and because it is the right
thing to do) we don't run .profile in a privileged shell - FreeBSD run
/etc/suid_profile in that case (not a good name, it also applies to setgid
shells) but I see no real need for that, we run /etc/profile in any case,
anything that would go in /etc/suid_profile can just go in /etc/profile
instead (with suitable guards so the commands only run in priv'd shells).

One or two minor DEBUG mode changes (notably having priv'd shells identify
themselves in the DEBUG trace) and sh.1 changes with doc of the "set +p"
change, the effect that has on $PSc and a few other wording tweaks.

XXX pullup -9 (not -8, this isn't worth it for the short lifetime
that has left - if it took 28+ years for anyone to notice this, it
cannot be having all that much effect).

branches: 1.33.2;

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.

Fix (hopefully) the problem reported on current-users by Patrick Welche.
we had incorrect usage of setstackmark()/popstackmark()

There was an ancient idiom (imported from CSRG in 1993) where code
can do:
setstackmark(&smark); loop until whatever condition {
/* do lots of code */ popstackmark(&smark);
} popstackmark(&smark);

The 1st (inner) popstackmark() resets the stack, conserving memory,
The 2nd one is needed just in case the "whatever condition" was never
true, and the first one was never executed.

This is (was) safe as all popstackmark() did was reset the stack.
That could be done over and over again with no harm.

That is, until 2000 when a fix from FreeBSD for another problem was
imported. That connected all the stack marks as a list (so they can be
located). That caused the problem, as the idiom was not changed, now
there is this list of marks, and popstackmark() was removing an entry.

It rarely (never?) caused any problems as the idiom was rarely used
(the shell used to do loops like above, mostly, without the inner
popstackmark()). Further, the stack mark list is only ever used when
a memory block is realloc'd.

That is, until last weekend - with the recent set of changes.

Part of that copied code from FreeBSD introduced the idiom above
into more functions - functions used much more, and with a greater
possibility of stack marks being set on blocks that are realloc'd
and so cause the problem. In the FreeBSD code, they changed the idiom,
and always do a setstackmark() immediately after the inner popstackmark().
But not for reasons related to a list of stack marks, as in the
intervening period, FreeBSD deleted that, but for another reason.

We do not have their issue, and I did not believe that their
updated idiom was needed (I did some analysis of exactly this issue -
just missed the important part!), and just continued using the old one.
Hence Patrick's core dump....

The solution used here is to split popstackmark() into 2 halves,
popstackmark() continues to do what it has (recently) done,
but is now implemented as a call of (a new func) rststackmark()
which does all the original work of popstackmark - but not removing
the entry from the stack mark list (which remains in popstackmark()).
Then in the idiom above, the inner popstackmark() turns into a call of
rststackmark() so the stack is reset, but the stack mark list is
unchanged. Tail recursion elimination makes this essentially free.

Minor cleanups to growstackblock(). This should really change
nothing that matters, but might be slightly more robust/complete.

branches: 1.30.4; 1.30.6;
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'.

branches: 1.29.62;
Fix inconsistent definitions

branches: 1.28.22;
Move UCB-licensed code from 4-clause to 3-clause licence.

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

Support command -p, -v and -V as posix
Stop temporary PATH assigments messing up hash table
Fix sh -c -e "echo $0 $*" -a x (as posix)
(agreed by christos)

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...)

- it is wrong to put inton/intoff arount ckmalloc(), because the code
around it is the one that does this.
- whitespace fixes.

Rename ALIGN to SHELL_ALIGN and simplify macro so that it does not have side
effects, and add double to it, so that it aligns doubles correctly too. This
is just a workaround to fix the sparc64 problem where ALIGN() is now defined
in some include file to be 16 instead of 8. Thanks to martin for debugging this.

PR/11283: Hubert Feyrer: random memory corruption executing commands:
Fix from FreeBSD:

growstackblock() sometimes relocates a stack_block considered empty
without properly relocating stack marks referencing that block.
The first call to popstackmark() with the unrelocated stack mark
as argument then causes sh to abort.

Relocating the relevant stack marks seems to solve this problem.

The patch changes the semantics of popstackmark() somewhat. It can
only be called once after a call to setstackmark(), thus cmdloop() in
main.c needs an extra call to setstackmark().

Wrap malloc() calls with an INTOFF/INTON pair. Fixes PR 8414.

branches: 1.21.10;
Include our local includes after the system's ones.

branches: 1.20.2;
Fix compiler warnings.

kill 'register'

PR/2808: Remove trailing whitespace (from FreeBSD)

branches: 1.17.2;
Fix growstackblock() 'newlen' calculations:
(1) it needs to be ALIGNed for both halves of the 'if,' and
(2) if you're going to claim that you now have ALIGN(newlen)
bytes left, you should have actually allocated
ALIGN(newlen), rather than just 'newlen' bytes.

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

convert to new RCS id conventions.

Fix that last bug in a less expensive way.

take two: make grabstackstr() work correctly, in the face of strange filling.

Remove previous misguided change.

don't play fast and loose with memory block allcation. try to allocate
in more-round sizes, but realize that not everybody will fill them up
exactly.

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

Eliminate uses of some obsolete functions.

Add RCS ids.

use prototypes provided by header files instead of our own

Include appropriate header files to bring function prototypes into scope.

sync with 4.4lite

Add RCS identifiers.

changed "Id" to "Header" for rcsids

added rcs ids to all files

branches: 1.1.1;
Initial revision

Use a type-correct end marker for strstrcat() rather than NULL, as
for a function with unknown number & types of args, the compiler isn't
able to automatically convert to the correct type. Issue pointed out
in off list e-mail by Rolland Illig ... Thanks.

The first arg (pointer to where to put length of result) is of a known
type, so doesn't have the same issue - we can keep using NULL for that
one when the length isn't needed.

Also, make sure to return a correctly null terminated null string in
the (absurd) case that there are no non-null args to strstrcat() (though
there are much better ways to generate "" on the stack). Since there is
currently just one call in the code, and it has real string args, this
isn't an issue for now, but who knows, some day.

NFCI - if there is any real change, then it is a change that is required.

XXX pullup -9 (together with the previous changes)

PR bin/56464

After almost 30 years, finally do the right thing and read $HOME/.profile
rather than .profile in the initial directory (it was that way in version
1.1 ...) All other ash descendants seem to have fixed this long ago.

While here, copy a feature from FreeBSD which allows "set +p" (if a
shell run by a setuid process with the -p flag is privileged) to reset
the privileges. Once done (the set +p) it cannot be undone (a later
set -p sets the 'p' flag, but that's all it does) - that just becomes a
one bit storage location.

We do this, as (also copying from FreeBSD, and because it is the right
thing to do) we don't run .profile in a privileged shell - FreeBSD run
/etc/suid_profile in that case (not a good name, it also applies to setgid
shells) but I see no real need for that, we run /etc/profile in any case,
anything that would go in /etc/suid_profile can just go in /etc/profile
instead (with suitable guards so the commands only run in priv'd shells).

One or two minor DEBUG mode changes (notably having priv'd shells identify
themselves in the DEBUG trace) and sh.1 changes with doc of the "set +p"
change, the effect that has on $PSc and a few other wording tweaks.

XXX pullup -9 (not -8, this isn't worth it for the short lifetime
that has left - if it took 28+ years for anyone to notice this, it
cannot be having all that much effect).

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.

Fix (hopefully) the problem reported on current-users by Patrick Welche.
we had incorrect usage of setstackmark()/popstackmark()

There was an ancient idiom (imported from CSRG in 1993) where code
can do:
setstackmark(&smark); loop until whatever condition {
/* do lots of code */ popstackmark(&smark);
} popstackmark(&smark);

The 1st (inner) popstackmark() resets the stack, conserving memory,
The 2nd one is needed just in case the "whatever condition" was never
true, and the first one was never executed.

This is (was) safe as all popstackmark() did was reset the stack.
That could be done over and over again with no harm.

That is, until 2000 when a fix from FreeBSD for another problem was
imported. That connected all the stack marks as a list (so they can be
located). That caused the problem, as the idiom was not changed, now
there is this list of marks, and popstackmark() was removing an entry.

It rarely (never?) caused any problems as the idiom was rarely used
(the shell used to do loops like above, mostly, without the inner
popstackmark()). Further, the stack mark list is only ever used when
a memory block is realloc'd.

That is, until last weekend - with the recent set of changes.

Part of that copied code from FreeBSD introduced the idiom above
into more functions - functions used much more, and with a greater
possibility of stack marks being set on blocks that are realloc'd
and so cause the problem. In the FreeBSD code, they changed the idiom,
and always do a setstackmark() immediately after the inner popstackmark().
But not for reasons related to a list of stack marks, as in the
intervening period, FreeBSD deleted that, but for another reason.

We do not have their issue, and I did not believe that their
updated idiom was needed (I did some analysis of exactly this issue -
just missed the important part!), and just continued using the old one.
Hence Patrick's core dump....

The solution used here is to split popstackmark() into 2 halves,
popstackmark() continues to do what it has (recently) done,
but is now implemented as a call of (a new func) rststackmark()
which does all the original work of popstackmark - but not removing
the entry from the stack mark list (which remains in popstackmark()).
Then in the idiom above, the inner popstackmark() turns into a call of
rststackmark() so the stack is reset, but the stack mark list is
unchanged. Tail recursion elimination makes this essentially free.

Minor cleanups to growstackblock(). This should really change
nothing that matters, but might be slightly more robust/complete.

branches: 1.30.4; 1.30.6;
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'.

branches: 1.29.62;
Fix inconsistent definitions

branches: 1.28.22;
Move UCB-licensed code from 4-clause to 3-clause licence.

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

Support command -p, -v and -V as posix
Stop temporary PATH assigments messing up hash table
Fix sh -c -e "echo $0 $*" -a x (as posix)
(agreed by christos)

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...)

- it is wrong to put inton/intoff arount ckmalloc(), because the code
around it is the one that does this.
- whitespace fixes.

Rename ALIGN to SHELL_ALIGN and simplify macro so that it does not have side
effects, and add double to it, so that it aligns doubles correctly too. This
is just a workaround to fix the sparc64 problem where ALIGN() is now defined
in some include file to be 16 instead of 8. Thanks to martin for debugging this.

PR/11283: Hubert Feyrer: random memory corruption executing commands:
Fix from FreeBSD:

growstackblock() sometimes relocates a stack_block considered empty
without properly relocating stack marks referencing that block.
The first call to popstackmark() with the unrelocated stack mark
as argument then causes sh to abort.

Relocating the relevant stack marks seems to solve this problem.

The patch changes the semantics of popstackmark() somewhat. It can
only be called once after a call to setstackmark(), thus cmdloop() in
main.c needs an extra call to setstackmark().

Wrap malloc() calls with an INTOFF/INTON pair. Fixes PR 8414.

branches: 1.21.10;
Include our local includes after the system's ones.

branches: 1.20.2;
Fix compiler warnings.

kill 'register'

PR/2808: Remove trailing whitespace (from FreeBSD)

branches: 1.17.2;
Fix growstackblock() 'newlen' calculations:
(1) it needs to be ALIGNed for both halves of the 'if,' and
(2) if you're going to claim that you now have ALIGN(newlen)
bytes left, you should have actually allocated
ALIGN(newlen), rather than just 'newlen' bytes.

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

convert to new RCS id conventions.

Fix that last bug in a less expensive way.

take two: make grabstackstr() work correctly, in the face of strange filling.

Remove previous misguided change.

don't play fast and loose with memory block allcation. try to allocate
in more-round sizes, but realize that not everybody will fill them up
exactly.

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

Eliminate uses of some obsolete functions.

Add RCS ids.

use prototypes provided by header files instead of our own

Include appropriate header files to bring function prototypes into scope.

sync with 4.4lite

Add RCS identifiers.

changed "Id" to "Header" for rcsids

added rcs ids to all files

branches: 1.1.1;
Initial revision

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.

Fix (hopefully) the problem reported on current-users by Patrick Welche.
we had incorrect usage of setstackmark()/popstackmark()

There was an ancient idiom (imported from CSRG in 1993) where code
can do:
setstackmark(&smark); loop until whatever condition {
/* do lots of code */ popstackmark(&smark);
} popstackmark(&smark);

The 1st (inner) popstackmark() resets the stack, conserving memory,
The 2nd one is needed just in case the "whatever condition" was never
true, and the first one was never executed.

This is (was) safe as all popstackmark() did was reset the stack.
That could be done over and over again with no harm.

That is, until 2000 when a fix from FreeBSD for another problem was
imported. That connected all the stack marks as a list (so they can be
located). That caused the problem, as the idiom was not changed, now
there is this list of marks, and popstackmark() was removing an entry.

It rarely (never?) caused any problems as the idiom was rarely used
(the shell used to do loops like above, mostly, without the inner
popstackmark()). Further, the stack mark list is only ever used when
a memory block is realloc'd.

That is, until last weekend - with the recent set of changes.

Part of that copied code from FreeBSD introduced the idiom above
into more functions - functions used much more, and with a greater
possibility of stack marks being set on blocks that are realloc'd
and so cause the problem. In the FreeBSD code, they changed the idiom,
and always do a setstackmark() immediately after the inner popstackmark().
But not for reasons related to a list of stack marks, as in the
intervening period, FreeBSD deleted that, but for another reason.

We do not have their issue, and I did not believe that their
updated idiom was needed (I did some analysis of exactly this issue -
just missed the important part!), and just continued using the old one.
Hence Patrick's core dump....

The solution used here is to split popstackmark() into 2 halves,
popstackmark() continues to do what it has (recently) done,
but is now implemented as a call of (a new func) rststackmark()
which does all the original work of popstackmark - but not removing
the entry from the stack mark list (which remains in popstackmark()).
Then in the idiom above, the inner popstackmark() turns into a call of
rststackmark() so the stack is reset, but the stack mark list is
unchanged. Tail recursion elimination makes this essentially free.

Minor cleanups to growstackblock(). This should really change
nothing that matters, but might be slightly more robust/complete.

branches: 1.30.4;
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'.

branches: 1.29.62;
Fix inconsistent definitions

branches: 1.28.22;
Move UCB-licensed code from 4-clause to 3-clause licence.

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

Support command -p, -v and -V as posix
Stop temporary PATH assigments messing up hash table
Fix sh -c -e "echo $0 $*" -a x (as posix)
(agreed by christos)

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...)

- it is wrong to put inton/intoff arount ckmalloc(), because the code
around it is the one that does this.
- whitespace fixes.

Rename ALIGN to SHELL_ALIGN and simplify macro so that it does not have side
effects, and add double to it, so that it aligns doubles correctly too. This
is just a workaround to fix the sparc64 problem where ALIGN() is now defined
in some include file to be 16 instead of 8. Thanks to martin for debugging this.

PR/11283: Hubert Feyrer: random memory corruption executing commands:
Fix from FreeBSD:

growstackblock() sometimes relocates a stack_block considered empty
without properly relocating stack marks referencing that block.
The first call to popstackmark() with the unrelocated stack mark
as argument then causes sh to abort.

Relocating the relevant stack marks seems to solve this problem.

The patch changes the semantics of popstackmark() somewhat. It can
only be called once after a call to setstackmark(), thus cmdloop() in
main.c needs an extra call to setstackmark().

Wrap malloc() calls with an INTOFF/INTON pair. Fixes PR 8414.

branches: 1.21.10;
Include our local includes after the system's ones.

branches: 1.20.2;
Fix compiler warnings.

kill 'register'

PR/2808: Remove trailing whitespace (from FreeBSD)

branches: 1.17.2;
Fix growstackblock() 'newlen' calculations:
(1) it needs to be ALIGNed for both halves of the 'if,' and
(2) if you're going to claim that you now have ALIGN(newlen)
bytes left, you should have actually allocated
ALIGN(newlen), rather than just 'newlen' bytes.

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

convert to new RCS id conventions.

Fix that last bug in a less expensive way.

take two: make grabstackstr() work correctly, in the face of strange filling.

Remove previous misguided change.

don't play fast and loose with memory block allcation. try to allocate
in more-round sizes, but realize that not everybody will fill them up
exactly.

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

Eliminate uses of some obsolete functions.

Add RCS ids.

use prototypes provided by header files instead of our own

Include appropriate header files to bring function prototypes into scope.

sync with 4.4lite

Add RCS identifiers.

changed "Id" to "Header" for rcsids

added rcs ids to all files

branches: 1.1.1;
Initial revision

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'.

Fix inconsistent definitions

branches: 1.28.22;
Move UCB-licensed code from 4-clause to 3-clause licence.

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

Support command -p, -v and -V as posix
Stop temporary PATH assigments messing up hash table
Fix sh -c -e "echo $0 $*" -a x (as posix)
(agreed by christos)

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...)

- it is wrong to put inton/intoff arount ckmalloc(), because the code
around it is the one that does this.
- whitespace fixes.

Rename ALIGN to SHELL_ALIGN and simplify macro so that it does not have side
effects, and add double to it, so that it aligns doubles correctly too. This
is just a workaround to fix the sparc64 problem where ALIGN() is now defined
in some include file to be 16 instead of 8. Thanks to martin for debugging this.

PR/11283: Hubert Feyrer: random memory corruption executing commands:
Fix from FreeBSD:

growstackblock() sometimes relocates a stack_block considered empty
without properly relocating stack marks referencing that block.
The first call to popstackmark() with the unrelocated stack mark
as argument then causes sh to abort.

Relocating the relevant stack marks seems to solve this problem.

The patch changes the semantics of popstackmark() somewhat. It can
only be called once after a call to setstackmark(), thus cmdloop() in
main.c needs an extra call to setstackmark().

Wrap malloc() calls with an INTOFF/INTON pair. Fixes PR 8414.

branches: 1.21.10;
Include our local includes after the system's ones.

branches: 1.20.2;
Fix compiler warnings.

kill 'register'

PR/2808: Remove trailing whitespace (from FreeBSD)

branches: 1.17.2;
Fix growstackblock() 'newlen' calculations:
(1) it needs to be ALIGNed for both halves of the 'if,' and
(2) if you're going to claim that you now have ALIGN(newlen)
bytes left, you should have actually allocated
ALIGN(newlen), rather than just 'newlen' bytes.

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

convert to new RCS id conventions.

Fix that last bug in a less expensive way.

take two: make grabstackstr() work correctly, in the face of strange filling.

Remove previous misguided change.

don't play fast and loose with memory block allcation. try to allocate
in more-round sizes, but realize that not everybody will fill them up
exactly.

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

Eliminate uses of some obsolete functions.

Add RCS ids.

use prototypes provided by header files instead of our own

Include appropriate header files to bring function prototypes into scope.

sync with 4.4lite

Add RCS identifiers.

changed "Id" to "Header" for rcsids

added rcs ids to all files

branches: 1.1.1;
Initial revision

Fix inconsistent definitions

branches: 1.28.22;
Move UCB-licensed code from 4-clause to 3-clause licence.

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

Support command -p, -v and -V as posix
Stop temporary PATH assigments messing up hash table
Fix sh -c -e "echo $0 $*" -a x (as posix)
(agreed by christos)

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...)

- it is wrong to put inton/intoff arount ckmalloc(), because the code
around it is the one that does this.
- whitespace fixes.

Rename ALIGN to SHELL_ALIGN and simplify macro so that it does not have side
effects, and add double to it, so that it aligns doubles correctly too. This
is just a workaround to fix the sparc64 problem where ALIGN() is now defined
in some include file to be 16 instead of 8. Thanks to martin for debugging this.

PR/11283: Hubert Feyrer: random memory corruption executing commands:
Fix from FreeBSD:

growstackblock() sometimes relocates a stack_block considered empty
without properly relocating stack marks referencing that block.
The first call to popstackmark() with the unrelocated stack mark
as argument then causes sh to abort.

Relocating the relevant stack marks seems to solve this problem.

The patch changes the semantics of popstackmark() somewhat. It can
only be called once after a call to setstackmark(), thus cmdloop() in
main.c needs an extra call to setstackmark().

Wrap malloc() calls with an INTOFF/INTON pair. Fixes PR 8414.

branches: 1.21.10;
Include our local includes after the system's ones.

branches: 1.20.2;
Fix compiler warnings.

kill 'register'

PR/2808: Remove trailing whitespace (from FreeBSD)

branches: 1.17.2;
Fix growstackblock() 'newlen' calculations:
(1) it needs to be ALIGNed for both halves of the 'if,' and
(2) if you're going to claim that you now have ALIGN(newlen)
bytes left, you should have actually allocated
ALIGN(newlen), rather than just 'newlen' bytes.

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

convert to new RCS id conventions.

Fix that last bug in a less expensive way.

take two: make grabstackstr() work correctly, in the face of strange filling.

Remove previous misguided change.

don't play fast and loose with memory block allcation. try to allocate
in more-round sizes, but realize that not everybody will fill them up
exactly.

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

Eliminate uses of some obsolete functions.

Add RCS ids.

use prototypes provided by header files instead of our own

Include appropriate header files to bring function prototypes into scope.

sync with 4.4lite

Add RCS identifiers.

changed "Id" to "Header" for rcsids

added rcs ids to all files

branches: 1.1.1;
Initial revision

44lite code

initial import of 386bsd-0.1 sources

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

Sync with trunk, per request of christos.

Pullup 1.23 [hubertf]:
Fixes PR 11283.

Pullup 1.22 [he]:
Wrap malloc() calls with an INTOFF/INTON pair. Fixes PR 8414.

sync with HEAD