Commit Graph

836 Commits

Author SHA1 Message Date
Jilles Tjoelker
5aa6dfda1c sh: Use O_CLOEXEC and F_DUPFD_CLOEXEC instead of separate fcntl() call. 2013-05-05 10:51:40 +00:00
Jilles Tjoelker
c4539460e3 sh: Improve error handling in read builtin:
* If read -t times out, return status as if interrupted by SIGALRM
  (formerly 1).
* If a trapped signal interrupts read, return status 128+sig (formerly 1).
* If [EINTR] occurs but there is no trap, retry the read (for example
  because of a SIGWINCH in interactive mode).
* If a read error occurs, write an error message and return status 2.

As before, a variable assignment error returns 2 and discards the remaining
data read.
2013-05-03 15:28:31 +00:00
Jilles Tjoelker
58c73bab93 sh: Don't consider jobs -s/-p as reporting the status of jobs.
This ensures that something like j=$(jobs -p) does not prevent any
status from being written to the terminal.
2013-04-27 14:07:25 +00:00
Joel Dahl
1ca3beb91f Document a few expansions for the $PS1 and $PS2 environmental variables.
PR:		173410
Submitted by:	Derek Wood <ddwood@outlook.com>
Reviewed by:	jilles
2013-04-21 19:55:38 +00:00
Jilles Tjoelker
6e0f89a4b4 sh: Don't modify exit status when break/continue/return passes !.
This matches what would happen if  ! P  were to be replaced with
if P; then false; else true; fi.

Example:
  f() { ! return 0; }; f
2013-04-12 15:19:35 +00:00
Jilles Tjoelker
7d919c164d sh: Add const to nodesavestr(). 2013-04-07 16:28:36 +00:00
Jilles Tjoelker
c6a453a430 sh: Write as much into the heredoc pipe as possible, to avoid forking.
Use non-blocking I/O to write as much as the pipe will accept (often 64K,
but it can be as little as 4K), avoiding the need for the ugly PIPESIZE
constant. If PIPESIZE was set too high, a deadlock would occur.
2013-04-02 21:34:38 +00:00
Jilles Tjoelker
46c6b52dfb sh: Fix various compiler warnings.
It now passes WARNS=7 with clang on i386.

GCC 4.2.1 does not understand setjmp() properly so will always trigger
-Wuninitialized. I will not add the volatile keywords to suppress this.
2013-04-01 17:18:22 +00:00
Joel Dahl
5127efa399 Minor mdoc fix. 2013-03-29 08:12:09 +00:00
Jilles Tjoelker
54ccc8b588 sh(1): Mention possible ambiguities with $(( and ((.
In some other shells, things like $((a);(b)) are command substitutions.

Also, there are shells that have an extension ((ARITH)) that evaluates an
arithmetic expression and returns status 1 if the result is zero, 0
otherwise. This extension may lead to ambiguity with two subshells starting
in sequence.
2013-03-24 22:48:45 +00:00
Jilles Tjoelker
d70ad6f2d0 sh: Recognize "--" and explicitly reject options in wait builtin.
If syntactically invalid job identifiers are to be taken as jobs that exited
with status 127, this should not apply to options, so that we can add
options later if need be.
2013-03-15 20:29:31 +00:00
Jilles Tjoelker
3fe1119f98 sh: When executing a trap, keep exit status along with evalskip.
This ensures 'return' in a trap returns the correct status to the caller.

If evalskip is not set or if it is overridden by a previous evalskip, keep
the old behaviour of restoring the exit status from before the trap.
2013-03-03 17:33:59 +00:00
Jilles Tjoelker
25e0f0f577 sh: If a SIGINT or SIGQUIT interrupts "wait", return status 128+sig. 2013-02-23 22:50:57 +00:00
Jilles Tjoelker
e9e9223546 sh: Fix a crash with the stackmark code.
If a stack mark is set while the current stack block is empty, the stack
block may move later on (because of realloc()) and the stack mark needs to
be updated. This updating does not happen after popstackmark() has been
called; therefore, call setstackmark() again if the stack mark is still
being used.

For some reason, this only affects a few users. I cannot reproduce it. The
situation seems quite rare as well because an empty stack block would
usually be freed (by popstackmark()) before execution reaches a
setstackmark() call.

PR:		175922
Tested by:	KT Sin
2013-02-19 23:46:51 +00:00
Jilles Tjoelker
1767d529f2 sh: Simplify mksyntax and make it fit for cross-compiling.
Now it outputs fixed files, which use constants provided by the C standard
library to determine appropriate values for the target machine.

Before, mksyntax inspected the host machine which resulted in subtle
breakage if e.g. char is signed on the host and unsigned on the target such
as when cross-compiling on x86 for ARM.

Tested using -funsigned-char on amd64. Compiling build-tools without it and
sh itself with it causes various tests to fail without this change but not
with this change. With consistent -funsigned-char, tests pass with or
without this change.

The mksyntax program could be removed and syntax.c and syntax.h committed to
the repository.

Submitted by:	Christoph Mallon
MFC after:	2 weeks
2013-02-07 22:42:33 +00:00
Jilles Tjoelker
eb64a9137b sh: Fix a comment. 2013-02-07 21:24:10 +00:00
Xin LI
5be97e72e6 Catch TRACE parameters up with r238888. This change is only needed when
debugging is enabled.
2013-02-07 19:00:54 +00:00
Jilles Tjoelker
eaf7719957 sh: Do not test for digit_contig in mksyntax.
ISO/IEC 9899:1999 (E) 5.2.1p3 guarantees that the values of the characters
0123456789 are contiguous.

The generated syntax.c and syntax.h remain the same.

Submitted by:	Christoph Mallon
2013-02-05 22:54:09 +00:00
Jilles Tjoelker
4dc6bdd3e7 sh: Expand here documents in the current process.
Expand here documents at the same point other redirections are expanded but
use a non-fork subshell environment (like simple command substitutions) for
compatibility. Substitition errors result in an empty here document like
before.

As a result, a fork is avoided for short (<4K) expanded here documents.

Unexpanded here documents (with quoted end marker after <<) are not affected
by this change. They already only forked when >4K.

Side effects:
* Order of expansion is slightly different.
* Slow expansions are not executed in parallel with the redirected command.
* A non-fork subshell environment is subtly different from a forked process.
2013-02-03 15:54:57 +00:00
Jilles Tjoelker
58570ac4a5 sh: Prefer our character classification functions to <ctype.h>. 2013-01-31 22:10:57 +00:00
Jilles Tjoelker
f9b7cc523d sh: Show negated commands (!) in jobs output. 2013-01-31 21:50:44 +00:00
Joel Dahl
cb5a6a58cb Add FILES section.
Discussed with:	jilles
2013-01-22 18:02:58 +00:00
Joel Dahl
5dd78c9f36 Change the $ENV example to use .shrc instead of .shinit. This is consistent
with what we use in /usr/share/skel/dot.profile.

Discussed with: jilles
2013-01-20 22:25:25 +00:00
Jilles Tjoelker
84edde8b1a sh: Move some stackmarks to fix high memory usage in some loops.
If a loop contained certain commands (such as redirected compound commands),
the temporary memory for the redirection was not freed between iterations of
the loop but only after the loop.

Put a stackmark in evaltree(), freeing memory whenever a node has been
evaluated. Some other stackmarks are then redundant; remove them.

Example:
  while :; do { :; } </dev/null; done
2013-01-20 21:28:05 +00:00
Jilles Tjoelker
59e0cc8e4a sh: Remove mkinit's initialization routine.
Instead, call the only init function left directly from main().
2013-01-20 12:44:50 +00:00
Jilles Tjoelker
60a6bf2a5a sh: Replace an mkinit use with an initialization. 2013-01-19 22:12:08 +00:00
Jilles Tjoelker
523646ee5c sh: Simplify cd-hash interaction.
Instead of rechecking relative paths for all hashed utilities after a cd,
track if any utility in cmdtable depends on a relative path in PATH.
If there is such a utility, cd clears the entire table.

As a result, the '*' in hash no longer happens.
2013-01-14 16:40:50 +00:00
Jilles Tjoelker
925420d09c sh: Pass $? to command substitution containing compound/multiple commands.
Example:
  false; echo $(echo $?; :)
2013-01-14 12:20:55 +00:00
Jilles Tjoelker
31d396587e sh: Fix crash when parsing '{ } &'.
MFC after:	1 week
2013-01-13 19:26:33 +00:00
Jilles Tjoelker
2c090c7168 sh: Don't lose $? when backquoted command ends with semicolon or newline.
An empty simple command was added and overwrote the exit status with 0.

This affects `...` but not $(...).

Example:
  v=`false;`; echo $?
2013-01-13 19:19:40 +00:00
Jilles Tjoelker
cdbd40cbb2 sh: Prefer strsignal() to accessing sys_siglist directly.
Accessing sys_siglist directly requires rtld to copy it from libc to the sh
executable's BSS. Also, strsignal() will put in the signal number for
unknown signals (FreeBSD-specific) so we need not do that ourselves.

Unfortunately, there is no function for sys_signame.
2012-12-25 14:17:09 +00:00
Jilles Tjoelker
d6d66cfc00 sh: Detect and flag write errors on stdout in builtins.
If there is a write error on stdout, a message will be printed (to stderr)
and the exit status will be changed to 2 if it would have been 0 or 1.

PR:		bin/158206
2012-12-12 22:01:10 +00:00
Jilles Tjoelker
22bec20ba9 sh: Remove an unused variable. 2012-11-14 14:08:24 +00:00
Jilles Tjoelker
35dab8598a sh: Forward-declare struct alias instead of giving up type safety via void * 2012-11-11 15:13:24 +00:00
Jilles Tjoelker
e964872f18 sh: Fix two issues when an alias is redefined:
* The last character is not displayed.
 * If the alias ends with itself (as a word), an infinite memory-eating loop
   occurs.

If an alias is defined initially, a space is appended to avoid recursion but
this did not happen when an alias was later modified.

PR:		bin/173418
Submitted by:	Daniel F.
MFC after:	1 week
2012-11-08 13:33:48 +00:00
Jilles Tjoelker
d172408c7e sh: Change cmdtype in tblentry from short to signed char.
If this is a smaller type than int anyway, we can make it the smallest
possible.
2012-11-05 17:52:18 +00:00
Jilles Tjoelker
422c281c83 sh: Use C99 flexible array instead of accessing array beyond bounds.
Although sufficient memory is available for a longer string in cmdname,
this is undefined behaviour anyway.

Side effect: for alignment reasons, an additional byte of memory is
allocated per hashed command.
2012-11-03 22:23:08 +00:00
Joel Dahl
a2442c2fa9 mdoc: don't nest displays. The markup here isn't adding anything anyway.
Fixes a mandoc lint warning.

Discussed with:	brueffer, Jason McIntyre <jmc@kerhand.co.uk>
2012-10-14 13:59:17 +00:00
Jilles Tjoelker
7cbda73825 sh: Prefer internal nextopt() to libc getopt().
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.
2012-09-15 21:56:30 +00:00
Jilles Tjoelker
d902a66b99 sh: Reduce code duplication: use setinputfile instead of open/setinputfd
combination.

MFC after:	2 weeks
2012-09-14 15:22:15 +00:00
Joel Dahl
afc5a69a1d Minor mdoc fix. 2012-09-11 17:57:03 +00:00
Jilles Tjoelker
36f7fbeae8 sh: Remove XXX comment about removing nextopt().
Using nextopt() avoids depending on the BSD-specific optreset feature in
getopt() and reduces code size (both source and binary).
2012-09-08 19:24:03 +00:00
Jilles Tjoelker
1794251add sh: Fix EINTR race condition in "wait" and "set -T" using sigsuspend().
When waiting for child processes using "wait" or if "set -T" is in effect, a
signal interrupts the wait. Make sure there is no window where the signal
handler may be invoked (setting a flag) just before going to sleep.

There is a similar race condition in the shell language, but scripts can
avoid it by exiting from the trap handler or enforcing synchronization using
a fifo.

If SIGCHLD is not trapped, a signal handler must be installed for it. Only
install this handler for the duration of the wait to avoid triggering
unexpected [EINTR] errors elsewhere.

Note that for some reason only SIGINT and SIGQUIT interrupt a "wait"
command. This remains the case.
2012-07-29 18:04:38 +00:00
Jilles Tjoelker
fb05913c5d sh: Do not ask for stopped/continued processes if we do not need them
rather than retrying wait3 if they happen.
2012-07-28 15:13:48 +00:00
Jilles Tjoelker
61fb716ac9 sh: Inline waitproc() into its only caller. 2012-07-28 14:56:50 +00:00
Jilles Tjoelker
faa787d323 sh: Track continued jobs (even if not continued by bg or fg).
This uses wait3's WCONTINUED flag.

There is no message for this. The change is visible in "jobs" or if the job
stops again.
2012-07-28 14:32:55 +00:00
Jilles Tjoelker
fa7ccda2c4 sh: Reset pendingsigs before checking pending traps, not after.
Otherwise, a signal arriving at exactly the right moment might not be
processed until another signal arrived.
2012-07-15 11:18:52 +00:00
Jilles Tjoelker
184dcee217 sh: Remove unused variable in_dowait. 2012-07-15 10:49:16 +00:00
Jilles Tjoelker
84fbdd8ca0 sh: Expand assignment-like words specially for export/readonly/local.
Examples:
  export x=~
now expands the tilde
  local y=$1
is now safe, even if $1 contains IFS characters or metacharacters.

For a word to "look like an assignment", it must start with a name followed
by an equals sign, none of which may be quoted.

The special treatment applies when the first word (potentially after
"command") is "export", "readonly" or "local". There may be quoting
characters but no expansions. If "local" is overridden with a function there
is no special treatment ("export" and "readonly" cannot be overridden with a
function).

If things like
  local arr=(1 2 3)
are ever allowed in the future, they cannot call a "local" function. This
would either be a run-time error or it would call the builtin.

This matches Austin Group bug #351, planned for the next issue of POSIX.1.

PR:		bin/166771
2012-07-15 10:19:43 +00:00
Pedro F. Giffuni
00c43e0ca4 Merge libedit adjustment from NetBSD.
On recent versions of NetBSD's libedit, el_gets
now sets el_len to -1 on error so we can
distinguish between a NULL string and an error.

This fixes sh from exiting with newer versions
of libedit now allowing EINTR to return.

Obtained from:	NetBSD
Reviewed by:	jilles
MFC after:	3 weeks
2012-07-11 22:17:58 +00:00