This Almquist extension was disabled long ago.
In pathname generation, components starting with '!!' were treated as
containing wildcards, causing unnecessary readdir (which could fail, causing
pathname generation to fail while it should not).
The buffer for generated pathnames could be too small in some cases. It
happened to be always at least PATH_MAX long, so there was never an overflow
if the resulting pathnames would be usable.
This bug may be abused if a script subjects input from an untrusted source
to pathname generation, which a bad idea anyhow. Most shell scripts do not
work on untrusted data. secteam@ says no advisory is necessary.
PR: bin/148733
Reported by: Changming Sun snnn119 at gmail com
MFC after: 10 days
Unless $! has been referenced for a particular job or $! still contains that
job's pid, forget about it after it has terminated. If $! has been
referenced, remember the job until the wait builtin has reported its
completion (either with the pid as parameter or without parameters).
In interactive mode, jobs are forgotten after termination has been reported,
which happens before primary prompts and through the jobs builtin. Even
then, though, remember a job if $! has been referenced.
This is similar to what is suggested by POSIX and should fix most memory
leaks (which also tend to cause sh to use more CPU time) with long running
scripts that start background jobs.
Caveats:
* Repeatedly referencing $! without ever doing 'wait', like
while :; do foo & echo started foo: $!; sleep 60; done
will still use a lot of memory and CPU time in the long run.
* The jobs and jobid builtins do not cause a job to be remembered for longer
like expanding $! does.
PR: bin/55346
These are git commits 36f0fa8fcbc8c7b2b194addd29100fb40e73e4e9 and
d6d06ff5c2ea0fa44becc5ef4340e5f2f15073e4 in dash.
Because this is the first code I'm importing from dash to expand.c, add the
Herbert Xu copyright notice which is in dash's expand.c.
When pathname expanding *\/, the CTLESC representing the quoted state was
erroneously taken as part of the * pathname component. This CTLESC was then
seen by the pattern matching code as escaping the '\0' terminating the
string.
The code is slightly different because dash converts the CTLESC characters
to backslashes and removes all the other CTL* characters to allow
substituting glob(3).
The effect of the bug was also slightly different from dash (where nothing
matched at all). Because a CTLESC can escape a '\0' in some way, whether
files were included despite the bug depended on memory that should not be
read. In particular, on many machines /*\/ expanded to a strict subset of
what /*/ expanded to.
Example:
echo /*"/null"
This should print /dev/null, not /*/null.
PR: bin/146378
Obtained from: dash
This applies to word in ${v-word}, ${v+word}, ${v=word}, ${v?word} (which
inherits quoting from the outside) and in ${v%word}, ${v%%word}, ${v#word},
${v##word} (which does not inherit any quoting).
In all cases tilde expansion is only attempted at the start of word, even if
word contains spaces. This agrees with POSIX and other shells.
This is the last part of the patch tested in the exp-run.
Exp-run done by: erwin (with some other sh(1) changes)
Note that this depends on r206145 for allowing pattern match characters to
have their special meaning inside a double-quoted expansion like "${v%pat}".
PR: bin/117748
Exp-run done by: erwin (with some other sh(1) changes)
- correctly handle error output in $(builtin 2>&1), clarify out1/out2 vs
output/errout in the code
- treat all builtins as regular builtins so errors do not abort the shell
and variable assignments do not persist
- respect the caller's INTOFF
Some bugs still exist:
- expansion errors may still abort the shell
- some side effects of expansions and builtins persist
That is, do not do tilde expansion if any of the CTL* bytes (\201-\210), not
only CTLESC and CTLQUOTEMARK, are encountered. Such an expansion would look
up a user name with sh's internal representation.
The parser does not currently distinguish between backslashed and
unbackslashed \201-\210, so tilde expansion of user names with these bytes
in them is not so easy to fix.
This seems more useful and will likely be in the next POSIX standard.
Also document more precisely in the man page what set -u does (note that
$@, $* and $! are the only special parameters that can ever be unset, all
the others are always set, although they may be empty).
in particular "$@"$ifschar if the final positional parameter is empty.
With the NetBSD code, adding the $ifschar removes a parameter.
PR: standards/79067
Approved by: ed (mentor) (implicit)
Portability Utilities" option.
Often configure scripts generated by the autotools test if $LINENO works and
refuse to use /bin/sh if not.
Package test run by: pav
issue a syntax error immediately but save the information that it is erroneous
for later when the parameter expansion is actually done. This means eg. "false
&& ${}" will not generate an error which seems to be required by POSIX.
Include the invalid parameter expansion in the error message (sometimes
abbreviated with ... because recovering it would require a lot of code).
PR: 105078
Submitted by: emaste
and linting procedure:
1. Remove useless sub-expression:
- if (*start || (!ifsspc && start > string && (nulonly || 1))) {
+ if (*start || (!ifsspc && start > string)) {
The sub-expression "(nulonly || 1)" always evaluates to true and
according to CVS logs seems to be just a left-over from some
debugging and introduced by accident. Removing the sub-expression
doesn't change semantics and a code inspection showed that the
variable "nulonly" is also not necessary here in any way (and the
expression would require fixing instead of removing).
2. Remove dead code:
- if (backslash && c == '\\') {
- if (read(STDIN_FILENO, &c, 1) != 1) {
- status = 1;
- break;
- }
- STPUTC(c, p);
- } else if (ap[1] != NULL && strchr(ifs, c) != NULL) {
+ if (ap[1] != NULL && strchr(ifs, c) != NULL) {
Inspection of the control and data flow showed that variable
"backslash" is always false (0) when the "if"-expression is
evaluated, hence the whole block is effectively dead code.
Additionally, the skipping of characters after a backslash is already
performed correctly a few lines above, so this code is also not
needed at all. According to the CVS logs and the ASH 0.2 sources,
this code existed in this way already since its early days.
3. Cleanup Style:
- ! trap[signo][0] == '\0' &&
+ ! (trap[signo][0] == '\0') &&
The expression wants to ensure the trap is not assigned the empty
string. But the "!" operator has higher precedence than "==", so the
comparison should be put into parenthesis to form the intended way of
expression. Nevertheless the code was effectively not really broken
as both particular NUL comparisons are semantically equal, of course.
But the parenthesized version is a lot more intuitive.
4. Remove shadowing variable declaration:
- char *q;
The declaration of symbol "q" hides another identical declaration of
"q" in the same context. As the other "q" is already reused multiple
times and also can be reused again without negative side-effects,
just remove the shadowing declaration.
5. Just small cosmetics:
- if (ifsset() != 0)
+ if (ifsset())
The ifsset() macro is already coded by returning the boolean result
of a comparison operator, so no need to compare this boolean result
again against a numerical value. This also aligns the macros usage to
the remaining existing code.
Reviewed by: stefanf@
converting the stat() call to a lstat() call, which will cover the
situation. One can exercise this bug by referring a dangling link with
something like */the-link.
Approved by: re (scottl)
Submitted by: Simon 'corecode' Schubert [corecode fs ei tum de]
Obtained from: NetBSD via DragonFlyBSD (NetBSD rev. 1.51 and DragonFly
rev. 1.6)
MFC After: 3 days
- Removed dead declarations
- Made objects that should have been declared as static, static.
The changes use STATIC instead of static, following the existing
convention in the rest of the code.
Approved by: schweikh (mentor)
MFC after: 2 weeks
output buffer, don't insert them at all. This prevents a buffer
*underrun* when the substitution consists completely of newlines
(e.g. `echo`) and the byte before the source buffer to which p
points is a '\n', in which case more characters would be removed
from the output buffer than were inserted.
This fixes certain port builds on sparc64.
Approved by: re (scottl)
Reviewed by: des, tjr
are later stripped with rmescapes() in expandarg(). If the filename has
already been unescaped, doing it again in rmescapes() can walk off the
end of the string, leading to memory corruption and eventually SIGSEGV.
Noticed by: kris
o Old-style K&R declarations have been converted to new C89 style
o register has been removed
o prototype for main() has been removed (gcc3 makes it an error)
o int main(int argc, char *argv[]) is the preferred main definition.
o Attempt to not break style(9) conformance for declarations more than
they already are.
o Change
int
foo() {
...
to
int
foo(void)
{
...
value CTLARI since this might break expansion of arithmetic expressions.
Don't access memory below start of stackblock.
Problem analyzed by hunt@iprg.nokia.com, slightly different patch applied.
PR: 24443
Submitted by: hunt@iprg.nokia.com
representation of the expression is quoted. Take care of this when
doing pattern matching in conjunction with trimming.
#!/bin/sh
c=d:e; echo "${c%:e}"
PR: NetBSD PR#7231
Noticed by: Havard Eidnes <Havard.Eidnes@runit.sintef.no>
Don't output double-quotes inside variable expansion/arithmetic
expansion region in here-documents. When leaving the arithmetic
expansion syntax mode, adjust the dblquote flag according to
previous syntax, in order to avoid splitting of quoted variables.
multiple times when performing nested variable expansion, and
preserve some quoting information in order to avoid removing
apparently empty expansion result.
