Before considering to execute a command substitution in the same process,
check if any of the expansions may have a side effect; if so, execute it in
a new process just like happens if it is not a single simple command.
Although the check happens at run time, it is a static check that does not
depend on current state. It is triggered by:
- expanding $! (which may cause the job to be remembered)
- ${var=value} default value assignment
- assignment operators in arithmetic
- parameter substitutions in arithmetic except ${#param}, $$, $# and $?
- command substitutions in arithmetic
This means that $((v+1)) does not prevent optimized command substitution,
whereas $(($v+1)) does, because $v might expand to something containing
assignment operators.
Scripts should not depend on these exact details for correctness. It is also
imaginable to have the shell fork if and when a side effect is encountered
or to create a new temporary namespace for variables.
Due to the $! change, the construct $(jobs $!) no longer works. The value of
$! should be stored in a variable outside command substitution first.
This test verifies that certain expansions without side effects do not
cause the command substitution to be executed in a child process.
This is not a correctness requirement, but it involves a nontrivial amount
of code and it would be unfortunate if it stopped working.
Command substitutions consisting of a single simple command are executed in
the main shell process but this should be invisible apart from performance
and very few exceptions such as $(trap).
If a command substitution consists of one special builtin and there is a
redirection error, this should not abort the outer shell.
It was fixed in r201366 by ignoring special builtin properties for command
substitutions consisting of one builtin.
The #define for warnx now behaves much like the libc function (except that
it uses sh command name and output).
Also, it now uses C99 __VA_ARGS__ so there is no need for three different
macros for 0, 1 or 2 parameters.
Constants in arithmetic starting with 0 should be octal only.
This avoids the following highly puzzling result:
$ echo $((018-017))
3
by making it an error instead.
The CTLESC byte to protect a special character was output before instead of
after a newline directly preceding the special character.
The special handling of newlines is because command substitutions discard
all trailing newlines.
o Create a sparse file instead of a fully zerod one. This trades the
possibiltiy of running out of space during the build for the speed
gain not having do write all those zeros...
Submitted by: n_hibma
When a fast machine first brings up some non TCP networking program
it is quite possible that we will drop packets due to the fact that
only one packet can be held per ARP entry. This leads to packets
being missed when a program starts or restarts if the ARP data is
not currently in the ARP cache.
This code adds a new sysctl, net.link.ether.inet.maxhold, which defines
a system wide maximum number of packets to be held in each ARP entry.
Up to maxhold packets are queued until an ARP reply is received or
the ARP times out. The default setting is the old value of 1
which has been part of the BSD networking code since time
immemorial.
Expose the time we hold an incomplete ARP entry by adding
the sysctl net.link.ether.inet.wait, which defaults to 20
seconds, the value used when the new ARP code was added..
Reviewed by: bz, rpaulo
MFC after: 3 weeks
Convert the tests to the perl prove format.
Remove obsolete TEST.README (results of an old TEST.sh for some old Unices)
and TEST.csh (old tests without correct values, far less complete than
TEST.sh).
MFC after: 1 week
- Use KERNCONFDIR with KERNCONF instead of copying the kernel config into the source tree
so included kernel configs work.
- Put more stuff in the _.bk/_.ik log file, not just make statements.
- Add the kernel config name to the pprint during kernel installation.
- Add NANO_MODULES providing a list of modules to build and install.
Reviewed by: imp
MFC after: 2 weeks
This moves the function of the noaliases variable into the checkkwd
variable. This way it is properly reset on errors and aliases can be used
normally in the commands for each case (the case labels recognize the
keyword esac but no aliases).
The new code is clearer as well.
Obtained from: dash
Apart from detecting breakage earlier or at all, this also fixes a segfault
in the testsuite. The "handling" of the breakage left an invalid internal
representation in some cases.
Examples:
echo a; do echo b
echo `) echo a`
echo `date; do do do`
Exp-run done by: pav (with some other sh(1) changes)
subevalvar() incorrectly assumed that CTLESC bytes were present iff the
expansion was quoted. However, they are present iff various processing such
as word splitting is to be done later on.
Example:
v=@$e@$e@$e@
y="${v##*"$e"}"
echo "$y"
failed if $e contained the magic CTLESC byte.
Exp-run done by: pav (with some other sh(1) changes)
The code is inspired by NetBSD sh somewhat, but different because we
preserve the old Almquist/Bourne/Korn ability to have an unquoted part in a
quoted ${v+word}. For example, "${v-"*"}" expands to $v as a single field if
v is set, but generates filenames otherwise.
Note that this is the only place where we split text literally from the
script (the similar ${v=word} assigns to v and then expands $v). The parser
must now add additional markers to allow the expansion code to know whether
arbitrary characters in substitutions are quoted.
Example:
for i in ${$+a b c}; do echo $i; done
Exp-run done by: pav (with some other sh(1) changes)
If double-quote state does not match, treat the '}' literally.
This ensures double-quote state remains the same before and after a
${v+-=?...} which helps with expand.c.
It makes things like
${foo+"\${bar}"}
which I have seen in the wild work as expected.
Exp-run done by: pav (with some other sh(1) changes)
This is a syntax error.
POSIX does not say explicitly whether defining a function with the same name
as a special builtin is allowed, but it does say that it is impossible to
call such a function.
A special builtin can still be overridden with an alias.
This commit is part of a set of changes that will ensure that when
something looks like a special builtin to the parser, it is one. (Not the
other way around, as it remains possible to call a special builtin named
by a variable or other substitution.)
Exp-run done by: pav (with some other sh(1) changes)
Add some conservative checks on function names:
- Disallow expansions or quoting characters; these can only be called via
strange control characters
- Disallow '/'; these functions cannot be called anyway, as exec.c assumes
they are pathnames
- Make the CTL* bytes work properly in function names.
These are syntax errors.
POSIX does not require us to support more than names (letters, digits and
underscores, not starting with a digit), but I do not want to restrict it
that much at this time.
Exp-run done by: pav (with some other sh(1) changes)
This is how ksh93 treats ! within a pipeline and makes the ! in
a | ! b | c
negate the exit status of the pipeline, as if it were
a | { ! b | c; }
Side effect: something like
f() ! a
is now a syntax error, because a function definition takes a command,
not a pipeline.
Exp-run done by: pav (with some other sh(1) changes)
feedback regarding user error.
Provide default loop and timing settings.
Add a new test that just times pread() without the open()/close().
Mark tests requiring a path argument so we can provide better feedback
to the user than EFAULT on (null).
Sponsored by: Google, Inc.
MFC after: 2 weeks
suffer fewer rounding errors with smaller numbers; fix argc validation
so multiple tests run on a single command line.
Sponsored by: Google, Inc.
MFC after: 2 weeks
argument to be passed on the command line, allowing file-related tests
to be pointed at wherever desired.
Sponsored by: Google, Inc.
MFC after: 2 weeks
each loop, rather than once up front. The distinction is unimportant
when doing a fix iteration count, but when using a timer, it should vary.
Sponsored by: Google, Inc.
MFC after: 2 weeks
- Use getopt rather than hand-parsed arguments
- Allow iterations to be specified and/or a new number of seconds bound
on the number of iterations
- Fix printout of timer resolution
- Add new tests, such as TCP and UDP socket creation, and open/read/close
of /dev/zero and /dev/null.
Sponsored by: Google, Inc.
MFC after: 2 weeks
microbenchmark suite:
- Use common benchmark_start/benchmark_stop routines to simplify
individual benchmarks.
- Add a central table of tests with names, where new tests can be
hooked in easily.
- Add new benchmarks for dup, shm_open, shm_open + fstat, fork,
vfork, vfork + exec, chroot, setuid.
- Accept a number of loops, not just a number of iterations.
- Report results more usefully in a table.
Sponsored by: Google, Inc.
MFC after: 2 weeks
and why. The first case is correct usage which has but one correct output.
The 2nd and 3rd cases are incorrect usage in which the exact output is
not standardized and various shells give various allowable output.
immediately written into the stack after the call. Instead let the caller
manage the "space left".
Previously, growstackstr()'s assumption causes problems with STACKSTRNUL()
where we want to be able to turn a stack into a C string, and later
pretend the NUL is not there.
This fixes a bug in STACKSTRNUL() (that grew the stack) where:
1. STADJUST() called after a STACKSTRNUL() results in an improper adjust.
This can be seen in ${var%pattern} and ${var%%pattern} evaluation.
2. Memory leak in STPUTC() called after a STACKSTRNUL().
Reviewed by: jilles
of printing a long list.
Add a default base port, and default mulitcast address to the
runner script.
Add support for specifying a different local and remote interface
in the runner script.
MFC after: 1 week
A closing bracket immediately after '[=' should not be treated as special.
Different from the submitted patch, a string ending with '[=' does not cause
access beyond the terminating '\0'.
PR: bin/150384
Submitted by: Richard Lowe
MFC after: 2 weeks
slice they are on. When NANO_LABEL is not defined, the fstab
generates entries that specify /dev/ad0s1a. When NANO_LABEL is
defined, it generates /dev/usb/${NANO_LABEL}s1a. The prior code
created the file system with a label of ${NANO_LABEL}s1, leading to
problems on boot.
Pointy hat to: imp@
nanobsd will build a system that uses this label (via
/dev/ufs/${NANO_LABEL}sX) in preference to NANO_DRIVE (well, it forces
NANO_DRIVE to be ufs/${NANO_LABEL}). This allows images that will
boot off usb stick or CF card easily well.
There is no change if you don't set this variable.
to growing the filesystem.
Refuse to attach providers where the metadata provider size is
wrong. This makes post-boot attaches behave consistently with
pre-boot attaches. Also refuse to restore metadata to a provider
of the wrong size without the new -f switch. The new -f switch
forces the metadata restoration despite the provider size, and
updates the provider size in the restored metadata to the correct
value.
Helped by: pjd
Reviewed by: pjd
into un-zeroed storage.
The original patch was questioned by Kirk as it forces the filesystem
to do excessive work initialising inodes on first use, and was never
MFC'd. This change mimics the newfs(8) approach of zeroing two
blocks of inodes for each new cylinder group.
Reviewed by: mckusick
MFC after: 3 weeks
are too long. Filenames escaping this test are caught later on,
so the bug doesn't cause any breakage.
Document the correct ustar limitations in pax. As I have no access
to the IEEE 1003.2 spec, I can only assume that the limitations
imposed are in fact correct.
Add regression tests for the filename limitations imposed by pax.
MFC after: 3 weeks
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).
pagesize()/pagesizes() after change to use aux vector. Note that
public function getosreldate() is different from libc-internal
__getosreldate() and does not use aux to fetch osreldate value.
MFC after: 1 month
POSIX does not allow constructs like:
if cmd; then fi
{ }
Add a colon dummy command, except in a test that verifies that such empty
lists do not cause crashes when used as a function definition.
In our implementation and most others, a break or continue in a dot script
can break or continue a loop outside the dot script. This should cause all
further commands in the dot script to be skipped. However, cmdloop() did not
know about this and continued to parse and execute commands from the dot
script.
As described in the man page, a return in a dot script in a function returns
from the function, not only from the dot script. There was a similar issue
as with break and continue. In various other shells, the return appears to
return from the dot script, but POSIX seems not very clear about this.
For mptest, add delays to I/O that simulate real disks better. This
also allows us to simulate what happens when a device goes away
with active transactions. It's pretty spectacular.
Sponsored by: Panasas
MFC after: 1 month
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
