This reduces code duplication and code size.
/usr/bin/printf is not affected.
Side effect: different error messages when certain builtins are passed
invalid options.
This uses vfork() for simple commands and command substitutions containing a
single simple command, invoking an external program under certain conditions
(no redirections or variable assignments, non-interactive shell, no job
control). These restrictions limit the amount of code executed in a vforked
child.
There is a large speedup (for example 35%) in microbenchmarks. The
difference in buildkernel is smaller (for example 0.5%) but still
statistically significant. See
http://lists.freebsd.org/pipermail/freebsd-hackers/2012-January/037581.html
for some numbers.
The use of vfork() can be disabled by setting a variable named
SH_DISABLE_VFORK.
Have mkbuiltins write the prototypes for the *cmd functions to builtins.h
instead of builtins.c and include builtins.h in more .c files instead of
duplicating prototypes for *cmd functions in other headers.
In optimized command substitution, save and restore any variables changed by
expansions (${var=value} and $((var=assigned))), instead of trying to
determine if an expansion may cause such changes.
If $! is referenced in optimized command substitution, do not cause jobs to
be remembered longer.
This fixes $(jobs $!) again, simplifies the man page and shortens the code.
Because we have no iconv in base, support for other charsets is not
possible.
Note that \u/\U are processed using the locale that was active when the
shell started. This is necessary to avoid behaviour that depends on the
parse/execute split (for example when placing braces around an entire
script). Therefore, UTF-8 encoding is implemented manually.
These are called "shell procedures" in the source.
If execve() failed with [ENOEXEC], the shell would reinitialize itself
and execute the program as a script. This requires a fair amount of code
which is not frequently used (most scripts have a #! magic number).
Therefore just execute a new instance of sh (_PATH_BSHELL) to run the
script.
* There is no plan for an alternative to the command "set".
* Attempting to unset a readonly variable has not raised an error for quite
a while, so the order of unsetting a variable and a function with the same
name does not matter.
MFC after: 1 week
An error message is written, the builtin is not executed, nonzero exit
status is returned but the shell does not abort.
This was already checked for special builtins and external commands, with
the same consequences except that the shell aborts for special builtins.
Obtained from: NetBSD
This allows doing things like LC_ALL=C some_builtin to run a builtin under a
different locale, just like is possible with external programs. The
immediate reason is that this allows making printf(1) a builtin without
breaking things like LC_NUMERIC=C printf '%f\n' 1.2
This change also affects special builtins, as even though the assignment is
persistent, the export is only to the builtin (unless the variable was
already exported).
Note: for this to work for builtins that also exist as external programs
such as /bin/test, the setlocale() call must be under #ifndef SHELL. The
shell will do the setlocale() calls which may not agree with the environment
variables.
It is already done by evalcommand(), unless special-ness has been removed,
in which case variable assignments should not persist. (These are currently
always special builtins, but this will change later: command builtin,
command substitution.)
This also fixes a memory leak when calling . with variable assignments.
Example:
valgrind --leak-check=full sh -c 'x=1 . /dev/null; x=2'
* exception handlers are now run with interrupts disabled, which avoids
many race conditions
* fix some cases where SIGINT only aborts one command and continues the
script, in particular if a SIGINT causes an EINTR error which trumped the
interrupt.
Example:
sh -c 'echo < /some/fifo; echo This should not be printed'
The fifo should not have writers. When pressing ctrl+c to abort the open,
the shell used to continue with the next command.
Example:
sh -c '/bin/echo < /some/fifo; echo This should not be printed'
Similar. Note, however, that this particular case did not and does not work
in interactive mode with job control enabled.
- remove ineffective and unnecessary (void) &var; [1]
- remove some unnecessary volatile keywords
- add a necessary volatile keyword
- save the old handler before doing something that could use the saved
value
Submitted by: Christoph Mallon [1]
Approved by: ed (mentor)
setenv(3) by tracking the size of the memory allocated instead of using
strlen() on the current value.
Convert all calls to POSIX from historic BSD API:
- unsetenv returns an int.
- putenv takes a char * instead of const char *.
- putenv no longer makes a copy of the input string.
- errno is set appropriately for POSIX. Exceptions involve bad environ
variable and internal initialization code. These both set errno to
EFAULT.
Several patches to base utilities to handle the POSIX changes from
Andrey Chernov's previous commit. A few I re-wrote to use setenv()
instead of putenv().
New regression module for tools/regression/environ to test these
functions. It also can be used to test the performance.
Bump __FreeBSD_version to 700050 due to API change.
PR: kern/99826
Approved by: wes
Approved by: re (kensmith)
Not because I admit they are technically wrong and not because of bug
reports (I receive nothing). But because I surprisingly meets so
strong opposition and resistance so lost any desire to continue that.
Anyone who interested in POSIX can dig out what changes and how
through cvs diffs.
1) Under POSIX unsetenv("foo=bar") is explicit error and not equal
to unsetenv("foo")
2) Prepare for upcomig POSIXed putenv() rewrite: make putenv() calls
portable and conforming to standard.
Utilities option. Its value is printed at the beginning of the line if tracing
(-x) is active. PS4 defaults to the string "+ " which is compatible with the
old behaviour to always print "+ ".
We still need to expand variables in PS1, PS2 and PS4.
PR: 46441 (part of)
Submitted by: schweikh
Obtained from: NetBSD
considered an error according to the Open Group Base Specification.
PR: standards/45738
Submitted by: Matthias Andree <matthias.andree@web.de>
MFC after: 3 days
