Commit Graph

45 Commits

Author SHA1 Message Date
Jilles Tjoelker
bd9b38d1f7 sh: Don't allocate a redirtab if there are no redirections.
Builtins (including variable assignments without command word), function
calls and redirected compound commands need to restore file descriptors
to their original state after execution. This is handled by allocating a
redirtab structure. These mallocs and frees show up heavily in pmcstat.

Only allocate a redirtab if there are actually redirections and maintain a
count of how many levels of REDIR_PUSH there are without redirtabs.

A simple loop without external programs like

sh -c 'i=0; w=$(printf %0100d 7); while [ "$i" -lt 1000000 ]; do
    i=$((i+1)); done'

is over 25% faster on an amd64 bhyve VM.
2016-01-30 21:21:25 +00:00
Jilles Tjoelker
33c5acf038 sh: Eliminate some gotos. 2014-10-05 21:51:36 +00:00
Jilles Tjoelker
1632bf1a88 sh: Fix possible memory leaks and double frees with unexpected SIGINT. 2014-03-26 20:43:40 +00:00
Jilles Tjoelker
61346cbdc7 sh: Add some consts. 2014-03-14 21:45:37 +00:00
Jilles Tjoelker
1b57cec7d9 sh: Make <&0 disable the </dev/null implicit in a background command.
Although <&0 does nothing, it is a redirection affecting standard input and
should therefore disable the </dev/null redirection implicit in a background
command.
2013-11-24 23:12:13 +00:00
Jilles Tjoelker
9bb8ccd642 sh: Remove unnecessary reset functions.
These are already handled by exception handlers.
2013-08-16 20:24:41 +00:00
Jilles Tjoelker
0bdd387178 sh: Remove #define MKINIT.
MKINIT only served for the removed mkinit. Many variables can be static now.
2013-07-25 19:48:15 +00:00
Jilles Tjoelker
338b821b0f sh: Remove mkinit.
Replace the RESET blocks with regular functions and a reset() function that
calls them all.

This code generation tool is unusual and does not appear to provide much
benefit. I do not think isolating the knowledge about which modules need to
be reset is worth an almost 500-line build tool and wider scope for
variables used by the reset functions.

Also, relying on reset functions is often wrong: the cleanup should be done
in exception handlers so that no stale state remains after 'command eval'
and the like.
2013-07-25 15:08:41 +00:00
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
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
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
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
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
3dec7d0c15 sh: Check whether dup2 was successful for >&FD and <&FD.
A failure (usually caused by FD not being open) is a redirection error.

Exp-run done by:	pav (with some other sh(1) changes)
2010-10-24 20:09:49 +00:00
David E. O'Brien
8832864298 In the spirit of r90111, depend on c89 and remove the "STATIC" macro
and its usage.
2010-10-13 22:18:03 +00:00
David E. O'Brien
aa7b6f8259 Consistently use "STATIC" for all functions in order to be able to set
breakpoints with in a debugger.  And use naked "static" for variables.

Noticed by:	bde
2010-10-13 04:01:01 +00:00
Jilles Tjoelker
e1ef314121 Fix some cases where file descriptors from redirections leak to programs.
- Redirecting fds that were not open before kept two copies of the
  redirected file.
    sh -c '{ :; } 7>/dev/null; fstat -p $$; true'
    (both fd 7 and 10 remained open)
- File descriptors used to restore things after redirection were not
  set close-on-exec, instead they were explicitly closed before executing
  a program normally and before executing a shell procedure. The latter
  must remain but the former is replaced by close-on-exec.
    sh -c 'exec 7</; { exec fstat -p $$; } 7>/dev/null; true'
    (fd 10 remained open)

The examples above are simpler than the testsuite because I do not want to
use fstat or procstat in the testsuite.
2009-11-29 22:33:59 +00:00
Jilles Tjoelker
9922c6d2d5 Fix various things about SIGINT handling:
* 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.
2009-11-22 18:23:30 +00:00
Jilles Tjoelker
deb090cba3 Fix race condition in noclobber option.
Formerly, it was possible for the file to be created between the check if it
existed and the open; the contents would then be lost.

Because this must use O_EXCL, noclobber > will not create a file through a
symlink anymore. This agrees with behaviour of other shells.

Approved by:	ed (mentor) (implicit)
2009-06-20 20:44:27 +00:00
Mark Murray
6195fb4102 Remove clause 3 from the UCB licenses.
OK'ed by:	imp, core
2004-04-06 20:06:54 +00:00
Dag-Erling Smørgrav
7e1c72660f Replace home-grown dup2() implementation with actual dup2() calls. This
should slightly reduce the number of system calls in critical portions of
the shell, and select a more efficient path through the fdalloc code.

Reviewed by:	bde
2004-01-21 12:50:01 +00:00
Diomidis Spinellis
2ba1b30bf5 Changes following CScout analysis:
- 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
2003-07-05 15:18:44 +00:00
Tim J. Robbins
9a7cafd9b8 Remove dead code which supported systems without O_APPEND, O_CREAT or SIGTSTP. 2002-09-29 12:38:25 +00:00
Tim J. Robbins
1c59560de9 Convert the remaining callers of errmsg() to use strerror(), and remove
errmsg() and its table of error messages.
2002-09-29 11:37:39 +00:00
Tim J. Robbins
5b99fa0514 Don't assume file descriptors fit in a short, use an int instead. 2002-07-18 12:24:35 +00:00
Tim J. Robbins
ce80ed021f Close file descriptors when [n]>&- and [n]<&- redirections are used.
This was broken by rev. 1.16.

PR:		40334
MFC after:	1 week
2002-07-09 08:55:46 +00:00
David E. O'Brien
2749b14129 Consistently use FBSDID 2002-06-30 05:15:05 +00:00
Tim J. Robbins
1a958c6653 Implement the -C (-o noclobber) option, which prevents existing regular
files from being overwritten by shell redirection.
2002-05-19 06:03:05 +00:00
Warner Losh
5134c3f799 o __P has been reoved
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)
	{
	...
2002-02-02 06:50:57 +00:00
Sergey Babkin
63f901ef53 The fix for >/dev/stdout, including Tor Egge's fix for the bug in the
original attempt of the fix. And yes, this time I've tried to build
world with it and it succeeded.

Submitted by:	Tor Egge
MFC after: 1 week
2002-01-13 14:37:40 +00:00
Alfred Perlstein
8f5c93f79f backout rev 1.14, it's breaking things. 2001-12-24 22:27:04 +00:00
Sergey Babkin
41f1be05da Added ability to do ">/dev/stdout". The apsfilter people are anxious
to get it MFCed in time for release 4.5.

MFC after: 2 weeks
2001-12-22 02:40:58 +00:00
Brian Somers
4682f420f2 Implement the <> redirection operator. 2000-10-03 23:13:14 +00:00
Martin Cracauer
6c48b6cf75 Include strerror(errno) in error messages after failed system calls.
Fix a warning.
1999-11-29 19:11:01 +00:00
Peter Wemm
2a4562393f $Id$ -> $FreeBSD$ 1999-08-27 23:15:48 +00:00
Philippe Charnier
3d7b5b9302 Add rcsid. Spelling. 1998-05-18 06:44:24 +00:00
Steve Price
79f569479b Fix redirection of unopened file descriptors and nuke register
keyword usage.

Obtained from: NetBSD
1997-04-28 03:25:13 +00:00
Peter Wemm
b97fa2ef50 Revert $FreeBSD$ to $Id$ 1997-02-22 14:13:04 +00:00
Jordan K. Hubbard
1130b656e5 Make the long-awaited change from $Id$ to $FreeBSD$
This will make a number of things easier in the future, as well as (finally!)
avoiding the Id-smashing problem which has plagued developers for so long.

Boy, I'm glad we're not using sup anymore.  This update would have been
insane otherwise.
1997-01-14 07:20:47 +00:00
Steve Price
ab0a217285 Merge in NetBSD mods and -Wall cleaning.
Obtained from: NetBSD, me
1996-12-14 06:20:03 +00:00
Peter Wemm
aa9caaf657 Merge of 4.4-Lite2 sh source, plus some gcc -Wall cleaning. This is a
merge of parallel duplicate work by Steve Price and myself. :-]

There are some changes to the build that are my fault...  mkinit.c was
trying (poorly) to duplicate some of the work that make(1) is designed to
do.  The Makefile hackery is my fault too, the depend list was incomplete
because of some explicit OBJS+= entries, so mkdep wasn't picking up their
source file #includes.

This closes a pile of /bin/sh PR's, but not all of them..

Submitted by: Steve Price <steve@bonsai.hiwaay.net>, peter
1996-09-01 10:22:36 +00:00
Joerg Wunsch
769bbc65e8 o rename ulimit -p into ulimit -u, so we are in agreement with bash
o fix brokeness for 1>&5 redirection, where `5' was an invalid file
  descriptor, but no error message has been generated

o fix brokeness for redirect to/from myself case
1995-10-21 00:47:32 +00:00
Rodney W. Grimes
2162b2d226 Remove trailing whitespace.
Reviewed by:	phk
1995-05-30 00:07:29 +00:00
David Greenman
89730b290a Added $Id$ 1994-09-24 02:59:15 +00:00
Rodney W. Grimes
4b88c807ea BSD 4.4 Lite bin Sources 1994-05-26 06:18:55 +00:00