Commit Graph

2573 Commits

Author SHA1 Message Date
Edward Tomasz Napierala
f9db2550b2 Add proper width calculation for time fields (time, cputime and usertime).
This fixes the ugly overflow in "ps aux" output for "[idle]".
2011-03-24 20:15:42 +00:00
Edward Tomasz Napierala
3bf92decd3 Make "LOGIN" and "CLASS" columns width scale properly instead of wasting space. 2011-03-24 17:20:24 +00:00
Jilles Tjoelker
ef89d04f13 sh(1): Describe subshell environment, command substitution more correctly.
POSIX does not require the shell to fork for a subshell environment, and we
use that possibility in various ways (command substitutions with a single
command and most subshells that are the final command of a shell process).
Therefore do not tie subshells to forking in the man page.

Command substitutions with expansions are a bit strange, causing a fork for
$(...$(($x))...) because $x might expand to y=2; they will probably be
changed later but this is how they work now.
2011-03-20 23:52:45 +00:00
Konstantin Belousov
a870bf2c31 Implement the usertime and systime keywords for ps, printing the
corresponding times reported by getrusage().

Submitted by:	Dan Nelson <dnelson allantgroup com>
MFC after:	1 week
2011-03-17 11:25:32 +00:00
Jilles Tjoelker
0cf90cd1d3 bin: Prefer strrchr() to rindex().
This removes the last index/rindex usage from /bin.
2011-03-15 22:22:11 +00:00
Jilles Tjoelker
35c641ed21 sh: Fix some parameter expansion variants ${#...}.
These already worked: $# ${#} ${##} ${#-} ${#?}
These now work as well: ${#+word} ${#-word} ${##word} ${#%word}

There is an ambiguity in the standard with ${#?}: it could be the length of
$? or it could be $# giving an error in the (impossible) case that it is not
set. We continue to use the former interpretation as it seems more useful.
2011-03-13 20:02:39 +00:00
Stefan Farfeleder
5db2bbd692 Remove unnecessary cast.
Reviewed by:	jilles
2011-03-07 07:31:15 +00:00
Jilles Tjoelker
ea381e691a sh(1): Reduce excessive semicolon-separated sentences.
Reported by:	Benjamin Kaduk
2011-03-06 21:20:53 +00:00
Edward Tomasz Napierala
7123f4cd6f Export login class information via kinfo and make it possible to view
it using "ps -o class".
2011-03-05 14:41:49 +00:00
Jilles Tjoelker
976018d24f sh: Fix some warnings in code for arithmetic expressions.
Submitted by:	eadler
2011-03-05 13:27:13 +00:00
Jilles Tjoelker
3658c9776e kill: Note that this is used both as a normal program and a shell builtin. 2011-03-01 21:48:22 +00:00
Xin LI
eaea8924ce Accept == as an alias of = which is a popular GNU extension.
This is intentionally undocumented for now since it's not part
of any standard.

MFC after:	1 month
2011-02-27 12:28:06 +00:00
Hajimu UMEMOTO
35bb448cd6 When WITH_ICONV is set, use our in-tree iconv. 2011-02-26 18:54:54 +00:00
Sergey Kandaurov
440c834c54 mdoc(7) markup.
Approved by:	avg (mentor), kib (mentor)
MFC after:	3 days
2011-02-21 16:03:39 +00:00
Rebecca Cran
6bccea7c2b Fix typos - remove duplicate "the".
PR:	bin/154928
Submitted by:	Eitan Adler <lists at eitanadler.com>
MFC after: 	3 days
2011-02-21 09:01:34 +00:00
Jilles Tjoelker
2fd7d6aab6 test: Note that this is used both as a normal program and a shell builtin.
MFC after:	1 week
2011-02-15 22:17:47 +00:00
Jilles Tjoelker
e9749129ad sh: Detect dividing the smallest integer by -1.
This overflows and on some architectures such as amd64 it generates SIGFPE.
Generate an error on all architectures.
2011-02-12 23:44:05 +00:00
Rebecca Cran
f68fbfedc1 Fix typos.
PR:	docs/131625
Submitted by:	Andrew Wright <andrew at qemg.org>
MFC after:	1 month
2011-02-12 20:28:15 +00:00
Jilles Tjoelker
075b72ef01 sh(1): Update description of arithmetic. 2011-02-08 23:19:40 +00:00
Jilles Tjoelker
6262b84eee sh: Import arithmetic expression code from dash.
New features:
* proper lazy evaluation of || and &&
* ?: ternary operator
* executable is considerably smaller (8K on i386) because lex and yacc are
  no longer used

Differences from dash:
* arith_t instead of intmax_t
* imaxdiv() not used
* unset or null variables default to 0
* let/exp builtin (undocumented, will probably be removed later)

Obtained from:	dash
2011-02-08 23:18:06 +00:00
Jilles Tjoelker
b15e9aa322 sh: Fix two things about {(...)} <redir:
* In {(...) <redir1;} <redir2, do not drop redir1.
* Maintain the difference between (...) <redir and {(...)} <redir:
  In (...) <redir, the redirection is performed in the child, while in
  {(...)} <redir it should be performed in the parent (like {(...); :;}
  <redir)
2011-02-05 15:02:19 +00:00
Jilles Tjoelker
c059d82290 sh: Remove clearcmdentry()'s now unused argument. 2011-02-05 14:08:51 +00:00
Jilles Tjoelker
ef0cb80dd4 sh: Forget all cached command locations on any PATH change.
POSIX requires this and it is simpler than the previous code that remembered
command locations when appending directories to PATH.

In particular,
  PATH=$PATH
is no longer a no-op but discards all cached command locations.
2011-02-05 14:01:46 +00:00
Jilles Tjoelker
604e8224f8 sh: Do not try to execute binary files as scripts.
If execve() returns an [ENOEXEC] error, check if the file is binary before
trying to execute it using sh. A file is considered binary if at least one
of the first 256 bytes is '\0'.

In particular, trying to execute ELF binaries for the wrong architecture now
fails with an "Exec format error" message instead of syntax errors and
potentially strange results.
2011-02-05 12:54:59 +00:00
Jilles Tjoelker
3835f47c7e sh: Remove special code for shell scripts without magic number.
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.
2011-02-04 22:47:55 +00:00
Jilles Tjoelker
12dacf622b Make sys_signame upper case.
This matches the constants from <signal.h> with 'SIG' removed, which POSIX
requires kill and trap to accept and 'kill -l' to write.

'kill -l', 'trap', 'trap -l' output is now upper case.

In Turkish locales, signal names with an upper case 'I' are now accepted,
while signal names with a lower case 'i' are no longer accepted, and the
output of 'killall -l' now contains proper capital 'I' without dot instead
of a dotted capital 'I'.
2011-02-04 16:40:50 +00:00
Jilles Tjoelker
834d160b3a sh: Return only 126 or 127 for execve() failures.
Do not return 2 for errors other than [EACCES] or [ENOENT].
2011-02-03 23:38:11 +00:00
Jilles Tjoelker
3e0b768c63 sh: Remove comment mentioning herefd, which is gone. 2011-02-02 21:48:53 +00:00
Jilles Tjoelker
b9f696953d sh: Send messages about signals to stderr.
This is required by POSIX and seems to make more sense.

See also r217557.
2011-01-30 22:57:52 +00:00
Jilles Tjoelker
cff1d84937 sh: Clean up some old comments:
* 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
2011-01-25 20:56:18 +00:00
Konstantin Belousov
f5f3977b8d Document P_FOLLOWFORK.
MFC after:	2 weeks
2011-01-25 11:04:16 +00:00
Jilles Tjoelker
0d5ccb45d8 sh: Fix signal messages being sent to the wrong file sometimes.
When a foreground job exits on a signal, a message is printed to stdout
about this. The buffer was not flushed after this which could result in the
message being written to the wrong file if the next command was a builtin
and had stdout redirected.

Example:
  sh -c 'kill -9 $$'; : > foo; echo FOO:; cat foo

Reported by:	gcooper
MFC after:	1 week
2011-01-18 21:18:31 +00:00
Jilles Tjoelker
421fb02139 sh(1): Document changes to 'exit' from traps. 2011-01-16 14:11:50 +00:00
Jilles Tjoelker
ebdfd6dc4d sh: If exit is used without args from a trap action, exit on the signal.
This is useful so that it is easier to exit on a signal than to reset the
trap to default and resend the signal. It matches ksh93. POSIX says that
'exit' without args from a trap action uses the exit status from the last
command before the trap, which is different from 'exit $?' and matches this
if the previous command is assumed to have exited on the signal.

If the signal is SIGSTOP, SIGTSTP, SIGTTIN or SIGTTOU, or if the default
action for the signal is to ignore it, a normal _exit(2) is done with exit
status 128+signal_number.
2011-01-16 13:56:41 +00:00
Jilles Tjoelker
a043cc4c68 sh: Fix some things about -- in trap:
* Make 'trap --' do the same as 'trap' instead of nothing.
* Make '--' stop option processing (note that '-' action is not an option).

Side effect: The error message for an unknown option is different.
2011-01-15 21:09:00 +00:00
Jilles Tjoelker
45b3c17647 sh: Make 'trap -l' look like 'kill -l'. 2011-01-14 21:30:27 +00:00
Jilles Tjoelker
33a8413363 sh: Follow-up to r216743, grabstackblock() can be replaced with stalloc().
grabstackblock() was used only once (but it is a very often executed piece
of code).
2011-01-09 22:47:58 +00:00
Jilles Tjoelker
4b45b49a70 sh: Remove special %builtin PATH entry.
All builtins are now always found before a PATH search.

Most ash derivatives have an undocumented feature where the presence of an
entry "%builtin" in $PATH will cause builtins to be checked at that point of
the PATH search, rather than before looking at any directories as documented
in the man page (very old versions do document this feature).

I am removing this feature from sh, as it complicates the code, may violate
expectations (for example, /usr/bin/alias is very close to a forkbomb with
PATH=/usr/bin:%builtin, only /usr/bin/builtin not being another link saves
it) and appears to be unused (all the %builtin google code search finds is
in some sort of ash source code).

Note that aliases and functions took and take precedence above builtins.
Because aliases work on a lexical level they can only ever be overridden on
a lexical level (quoting or preceding 'builtin' or 'command'). Allowing
override of functions via PATH does not really fit in the model of sh and it
would work differently from %builtin if implemented.

Note: POSIX says special builtins are found before functions. We comply to
this because we do not allow functions with the same name as a special
builtin.

Silence from:	freebsd-hackers@ (message sent 20101225)
Discussed with:	dougb
2011-01-09 21:07:30 +00:00
Konstantin Belousov
50a57dfbec Move repeated MAXSLP definition from machine/vmparam.h to sys/vmmeter.h.
Update the outdated comments describing MAXSLP and the process
selection algorithm for swap out.

Comments wording and reviewed by:	alc
2011-01-09 12:50:44 +00:00
Jilles Tjoelker
70df11eaad sh: Make exit without parameters from EXIT trap POSIX-compliant.
It should use the original exit status, just like falling off the
end of the trap handler.

Outside an EXIT trap, 'exit' is still equivalent to 'exit $?'.
2011-01-08 23:08:13 +00:00
Jilles Tjoelker
e23a66ac83 sh: Do not call exitshell() from evalcommand() unless evalcommand() forked
itself.

This ensures that certain traps caused by builtins are executed.
2011-01-05 23:17:29 +00:00
Jaakko Heinonen
b38dc7ebea Increase carried_error if we skip a file due to an error. This ensures
that setfacl(1) exits with proper exit status on failure.

PR:		bin/149780
Submitted by:	Ævar Arnfjörð Bjarmason (original version)
Reviewed by:	trasz
MFC after:	3 weeks
2011-01-03 17:17:31 +00:00
Jilles Tjoelker
850460c0f1 sh: Check readonly status for assignments on regular builtins.
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
2011-01-01 13:26:18 +00:00
Jilles Tjoelker
09683f46b9 sh: Check if dup2 for redirection from/to a file succeeds.
A failure (e.g. caused by ulimit -n being set very low) is a redirection
error.

Example:
  ulimit -n 9; exec 9<.
2010-12-31 18:20:17 +00:00
Jilles Tjoelker
11535bdf04 sh: Avoid side effects from builtins in optimized command substitution.
Change the criterion for builtins to be safe to execute in the same process
in optimized command substitution from a blacklist of only cd, . and eval to
a whitelist.

This avoids clobbering the main shell environment such as by $(exit 4) and
$(set -x).

The builtins jobid, jobs, times and trap can still show information not
available in a child process; this is deliberately permitted. (Changing
traps is not.)

For some builtins, whether they are safe depends on the arguments passed to
them. Some of these are always considered unsafe to keep things simple; this
only harms efficiency a little in the rare case they are used alone in a
command substitution.
2010-12-30 22:33:55 +00:00
Jilles Tjoelker
685a270543 sh: Properly restore exception handler in fc.
If SIGINT arrived at exactly the right moment (unlikely), an exception
handler in a no longer active stack frame would be called.

Because the old handler was not used in the normal path, clang thought it
was a dead value and if an exception happened it would longjmp() to garbage.
This caused builtins/fc1.0 to fail if histedit.c was compiled with clang.

MFC after:	1 week
2010-12-29 19:39:51 +00:00
Jilles Tjoelker
acd7984f96 sh: Don't do optimized command substitution if expansions have side effects.
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.
2010-12-28 21:27:08 +00:00
Jilles Tjoelker
45b71cd16e sh: Make expansion errors in optimized command substitution non-fatal.
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).
2010-12-28 13:28:24 +00:00
Jilles Tjoelker
ff802dc7bb sh: Simplify "stack string" code slightly.
Maintain a pointer to the end of the stack string area instead of how much
space is left. This simplifies the macros in memalloc.h. The places where
the new variable must be updated are only where the memory area is created,
destroyed or resized.
2010-12-27 22:18:27 +00:00
Jilles Tjoelker
78962f36d2 sh: Fix integer overflow check, it checked an uninitialized variable. 2010-12-26 13:41:53 +00:00