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2010-05-20start_command: close cmd->err descriptor when fork/spawn failsLibravatar bert Dvornik1-0/+2
Fix the problem where the cmd->err passed into start_command wasn't being properly closed when certain types of errors occurr. (Compare the affected code with the clean shutdown code later in the function.) On Windows, this problem would be triggered if mingw_spawnvpe() failed, which would happen if the command to be executed was malformed (e.g. a text file that didn't start with a #! line). If cmd->err was a pipe, the failure to close it could result in a hang while the other side was waiting (forever) for either input or pipe close, e.g. while trying to shove the output into the side band. On msysGit, this problem was causing a hang in t5516-fetch-push. [J6t: With a slight adjustment of the test case, the hang is also observed on Linux.] Signed-off-by: bert Dvornik <dvornik+git@gmail.com> Signed-off-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2010-04-11Merge branch 'jl/maint-submodule-gitfile-awareness'Libravatar Junio C Hamano1-3/+1
* jl/maint-submodule-gitfile-awareness: Windows: start_command: Support non-NULL dir in struct child_process
2010-04-11Windows: start_command: Support non-NULL dir in struct child_processLibravatar Johannes Sixt1-3/+1
A caller of start_command can set the member 'dir' to a directory to request that the child process starts with that directory as CWD. The first user of this feature was added recently in eee49b6 (Teach diff --submodule and status to handle .git files in submodules). On Windows, we have been lazy and had not implemented support for this feature, yet. This fixes the shortcoming. Signed-off-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2010-03-07Merge branch 'mw/maint-gcc-warns-unused-write'Libravatar Junio C Hamano1-4/+6
* mw/maint-gcc-warns-unused-write: run-command.c: fix build warnings on Ubuntu
2010-03-03run-command.c: fix build warnings on UbuntuLibravatar Michael Wookey1-4/+6
Building git on Ubuntu 9.10 warns that the return value of write(2) isn't checked. These warnings were introduced in commits: 2b541bf8 ("start_command: detect execvp failures early") a5487ddf ("start_command: report child process setup errors to the parent's stderr") GCC details: $ gcc --version gcc (Ubuntu 4.4.1-4ubuntu9) 4.4.1 Silence the warnings by reading (but not making use of) the return value of write(2). Signed-off-by: Michael Wookey <michaelwookey@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2010-02-05Merge branch 'sp/maint-push-sideband' into sp/push-sidebandLibravatar Junio C Hamano1-13/+77
* sp/maint-push-sideband: receive-pack: Send hook output over side band #2 receive-pack: Wrap status reports inside side-band-64k receive-pack: Refactor how capabilities are shown to the client send-pack: demultiplex a sideband stream with status data run-command: support custom fd-set in async run-command: Allow stderr to be a caller supplied pipe Update git fsck --full short description to mention packs Conflicts: run-command.c
2010-02-05run-command: support custom fd-set in asyncLibravatar Erik Faye-Lund1-13/+70
This patch adds the possibility to supply a set of non-0 file descriptors for async process communication instead of the default-created pipe. Additionally, we now support bi-directional communiction with the async procedure, by giving the async function both read and write file descriptors. To retain compatiblity and similar "API feel" with start_command, we require start_async callers to set .out = -1 to get a readable file descriptor. If either of .in or .out is 0, we supply no file descriptor to the async process. [sp: Note: Erik started this patch, and a huge bulk of it is his work. All bugs were introduced later by Shawn.] Signed-off-by: Erik Faye-Lund <kusmabite@gmail.com> Signed-off-by: Shawn O. Pearce <spearce@spearce.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2010-02-05run-command: Allow stderr to be a caller supplied pipeLibravatar Shawn O. Pearce1-0/+8
Like .out, .err may now be set to a file descriptor > 0, which is a writable pipe/socket/file that the child's stderr will be redirected into. Signed-off-by: Shawn O. Pearce <spearce@spearce.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2010-01-20Merge branch 'js/exec-error-report'Libravatar Junio C Hamano1-46/+131
* js/exec-error-report: Improve error message when a transport helper was not found start_command: detect execvp failures early run-command: move wait_or_whine earlier start_command: report child process setup errors to the parent's stderr Conflicts: Makefile
2010-01-18Merge branch 'js/windows'Libravatar Junio C Hamano1-40/+31
* js/windows: Do not use date.c:tm_to_time_t() from compat/mingw.c MSVC: Windows-native implementation for subset of Pthreads API MSVC: Fix an "incompatible pointer types" compiler warning Windows: avoid the "dup dance" when spawning a child process Windows: simplify the pipe(2) implementation Windows: boost startup by avoiding a static dependency on shell32.dll Windows: disable Python
2010-01-16Windows: avoid the "dup dance" when spawning a child processLibravatar Johannes Sixt1-40/+31
When stdin, stdout, or stderr must be redirected for a child process that on Windows is spawned using one of the spawn() functions of Microsoft's C runtime, then there is no choice other than to 1. make a backup copy of fd 0,1,2 with dup 2. dup2 the redirection source fd into 0,1,2 3. spawn 4. dup2 the backup back into 0,1,2 5. close the backup copy and the redirection source We used this idiom as well -- but we are not using the spawn() functions anymore! Instead, we have our own implementation. We had hardcoded that stdin, stdout, and stderr of the child process were inherited from the parent's fds 0, 1, and 2. But we can actually specify any fd. With this patch, the fds to inherit are passed from start_command()'s WIN32 section to our spawn implementation. This way, we can avoid the backup copies of the fds. The backup copies were a bug waiting to surface: The OS handles underlying the dup()ed fds were inherited by the child process (but were not associated with a file descriptor in the child). Consequently, the file or pipe represented by the OS handle remained open even after the backup copy was closed in the parent process until the child exited. Since our implementation of pipe() creates non-inheritable OS handles, we still dup() file descriptors in start_command() because dup() happens to create inheritable duplicates. (A nice side effect is that the fd cleanup in start_command is the same for Windows and Unix and remains unchanged.) Signed-off-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2010-01-10start_command: detect execvp failures earlyLibravatar Johannes Sixt1-1/+46
Previously, failures during execvp could be detected only by finish_command. However, in some situations it is beneficial for the parent process to know earlier that the child process will not run. The idea to use a pipe to signal failures to the parent process and the test case were lifted from patches by Ilari Liusvaara. Signed-off-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2010-01-10run-command: move wait_or_whine earlierLibravatar Johannes Sixt1-42/+42
We want to reuse it from start_command. Signed-off-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2010-01-10start_command: report child process setup errors to the parent's stderrLibravatar Johannes Sixt1-3/+43
When the child process's environment is set up in start_command(), error messages were written to wherever the parent redirected the child's stderr channel. However, even if the parent redirected the child's stderr, errors during this setup process, including the exec itself, are usually an indication of a problem in the parent's environment. Therefore, the error messages should go to the parent's stderr. Redirection of the child's error messages is usually only used to redirect hook error messages during client-server exchanges. In these cases, hook setup errors could be regarded as information leak. This patch makes a copy of stderr if necessary and uses a special die routine that is used for all die() calls in the child that sends the errors messages to the parent's stderr. The trace call that reported a failed execvp is removed (because it writes to stderr) and replaced by die_errno() with special treatment of ENOENT. The improvement in the error message can be seen with this sequence: mkdir .git/hooks/pre-commit git commit Previously, the error message was error: cannot run .git/hooks/pre-commit: No such file or directory and now it is fatal: cannot exec '.git/hooks/pre-commit': Permission denied Signed-off-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2010-01-05run-command: optimize out useless shell callsLibravatar Jeff King1-9/+11
If there are no metacharacters in the program to be run, we can just skip running the shell entirely and directly exec the program. The metacharacter test is pulled verbatim from launch_editor, which already implements this optimization. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2010-01-01run-command: add "use shell" optionLibravatar Jeff King1-0/+47
Many callsites run "sh -c $CMD" to run $CMD. We can make it a little simpler for them by factoring out the munging of argv. For simple cases with no arguments, this doesn't help much, but: 1. For cases with arguments, we save the caller from having to build the appropriate shell snippet. 2. We can later optimize to avoid the shell when there are no metacharacters in the program. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-09-18Test for WIN32 instead of __MINGW32_Libravatar Frank Li1-4/+4
The code which is conditional on MinGW32 is actually conditional on Windows. Use the WIN32 symbol, which is defined by the MINGW32 and MSVC environments, but not by Cygwin. Define SNPRINTF_SIZE_CORR=1 for MSVC too, as its vsnprintf function does not add NUL at the end of the buffer if the result fits the buffer size exactly. Signed-off-by: Frank Li <lznuaa@gmail.com> Signed-off-by: Marius Storm-Olsen <mstormo@gmail.com> Acked-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-09-18Fix __stdcall placement and function prototypeLibravatar Frank Li1-1/+1
MSVC requires __stdcall to be between the functions return value and the function name, and that the function pointer type is in the form of return_type (WINAPI *function_name)(arguments...) Signed-off-by: Frank Li <lznuaa@gmail.com> Signed-off-by: Marius Storm-Olsen <mstormo@gmail.com> Acked-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-09-18Avoid declaration after statementLibravatar Frank Li1-0/+2
MSVC does not understand this C99 style. Signed-off-by: Frank Li <lznuaa@gmail.com> Signed-off-by: Marius Storm-Olsen <mstormo@gmail.com> Acked-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-09-11start_command: do not clobber cmd->env on Windows code pathLibravatar Johannes Sixt1-5/+2
Previously, it would not be possible to call start_command twice for the same struct child_process that has env set. The fix is achieved by moving the loop that modifies the environment block into a helper function. This also allows us to make two other helper functions static. Signed-off-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-08-10Merge branch 'js/run-command-updates'Libravatar Junio C Hamano1-46/+59
* js/run-command-updates: api-run-command.txt: describe error behavior of run_command functions run-command.c: squelch a "use before assignment" warning receive-pack: remove unnecessary run_status report run_command: report failure to execute the program, but optionally don't run_command: encode deadly signal number in the return value run_command: report system call errors instead of returning error codes run_command: return exit code as positive value MinGW: simplify waitpid() emulation macros
2009-08-04run-command.c: squelch a "use before assignment" warningLibravatar David Soria Parra1-1/+1
i686-apple-darwin9-gcc-4.0.1 (GCC) 4.0.1 (Apple Inc. build 5490) compiler (and probably others) mistakenly thinks variable failed_errno is used before assigned. Work it around by giving it a fake initialization. Signed-off-by: David Soria Parra <dsp@php.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-07-06run_command: report failure to execute the program, but optionally don'tLibravatar Johannes Sixt1-4/+8
In the case where a program was not found, it was still the task of the caller to report an error to the user. Usually, this is an interesting case but only few callers actually reported a specific error (though many call sites report a generic error message regardless of the cause). With this change the error is reported by run_command, but since there is one call site in git.c that does not want that, an option is added to struct child_process, which is used to turn the error off. Signed-off-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-07-06run_command: encode deadly signal number in the return valueLibravatar Johannes Sixt1-1/+8
We now write the signal number in the error message if the program terminated by a signal. The negative return value is constructed such that after truncation to 8 bits it looks like a POSIX shell's $?: $ echo 0000 | { git upload-pack .; echo $? >&2; } | : error: git-upload-pack died of signal 13 141 Previously, the exit code was 255 instead of 141. Signed-off-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-07-06run_command: report system call errors instead of returning error codesLibravatar Johannes Sixt1-40/+49
The motivation for this change is that system call failures are serious errors that should be reported to the user, but only few callers took the burden to decode the error codes that the functions returned into error messages. If at all, then only an unspecific error message was given. A prominent example is this: $ git upload-pack . | : fatal: unable to run 'git-upload-pack' In this example, git-upload-pack, the external command invoked through the git wrapper, dies due to SIGPIPE, but the git wrapper does not bother to report the real cause. In fact, this very error message is copied to the syslog if git-daemon's client aborts the connection early. With this change, system call failures are reported immediately after the failure and only a generic failure code is returned to the caller. In the above example the error is now to the point: $ git upload-pack . | : error: git-upload-pack died of signal Note that there is no error report if the invoked program terminated with a non-zero exit code, because it is reasonable to expect that the invoked program has already reported an error. (But many run_command call sites nevertheless write a generic error message.) There was one special return code that was used to identify the case where run_command failed because the requested program could not be exec'd. This special case is now treated like a system call failure with errno set to ENOENT. No error is reported in this case, because the call site in git.c expects this as a normal result. Therefore, the callers that carefully decoded the return value still check for this condition. Signed-off-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-07-05run_command: return exit code as positive valueLibravatar Johannes Sixt1-8/+1
As a general guideline, functions in git's code return zero to indicate success and negative values to indicate failure. The run_command family of functions followed this guideline. But there are actually two different kinds of failure: - failures of system calls; - non-zero exit code of the program that was run. Usually, a non-zero exit code of the program is a failure and means a failure to the caller. Except that sometimes it does not. For example, the exit code of merge programs (e.g. external merge drivers) conveys information about how the merge failed, and not all exit calls are actually failures. Furthermore, the return value of run_command is sometimes used as exit code by the caller. This change arranges that the exit code of the program is returned as a positive value, which can now be regarded as the "result" of the function. System call failures continue to be reported as negative values. Signed-off-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-06-27Convert existing die(..., strerror(errno)) to die_errno()Libravatar Thomas Rast1-2/+2
Change calls to die(..., strerror(errno)) to use the new die_errno(). In the process, also make slight style adjustments: at least state _something_ about the function that failed (instead of just printing the pathname), and put paths in single quotes. Signed-off-by: Thomas Rast <trast@student.ethz.ch> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-05-01Fix a bunch of pointer declarations (codestyle)Libravatar Felipe Contreras1-1/+1
Essentially; s/type* /type */ as per the coding guidelines. Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-02-03Merge branch 'jk/maint-cleanup-after-exec-failure'Libravatar Junio C Hamano1-4/+14
* jk/maint-cleanup-after-exec-failure: git: use run_command() to execute dashed externals run_command(): help callers distinguish errors run_command(): handle missing command errors more gracefully git: s/run_command/run_builtin/
2009-01-28run_command(): handle missing command errors more gracefullyLibravatar Jeff King1-4/+14
When run_command() was asked to run a non-existant command, its behavior varied depending on the platform: - on POSIX systems, we would fork, and then after the execvp call failed, we could call die(), which prints a message to stderr and exits with code 128. - on Windows, we do a PATH lookup, realize the program isn't there, and then return ERR_RUN_COMMAND_FORK The goal of this patch is to make it clear to callers that the specific error was a missing command. To do this, we will return the error code ERR_RUN_COMMAND_EXEC, which is already defined in run-command.h, checked for in several places, but never actually gets set. The new behavior is: - on POSIX systems, we exit the forked process with code 127 (the same as the shell uses to report missing commands). The parent process recognizes this code and returns an EXEC error. The stderr message is silenced, since the caller may be speculatively trying to run a command. Instead, we use trace_printf so that somebody interested in debugging can see the error that occured. - on Windows, we check errno, which is already set correctly by mingw_spawnvpe, and report an EXEC error instead of a FORK error Thus it is safe to speculatively run a command: int r = run_command_v_opt(argv, 0); if (r == -ERR_RUN_COMMAND_EXEC) /* oops, it wasn't found; try something else */ else /* we failed for some other reason, error is in r */ Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-01-17run_hook(): allow more than 9 hook argumentsLibravatar Stephan Beyer1-9/+9
This is done using the ALLOC_GROW macro. Signed-off-by: Stephan Beyer <s-beyer@gmx.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-01-17run_hook(): check the executability of the hook before filling argvLibravatar Stephan Beyer1-3/+3
Signed-off-by: Stephan Beyer <s-beyer@gmx.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-01-17Move run_hook() from builtin-commit.c into run-command.c (libgit)Libravatar Stephan Beyer1-0/+45
A function that runs a hook is used in several Git commands. builtin-commit.c has the one that is most general for cases without piping. The one in builtin-gc.c prints some useful warnings. This patch moves a merged version of these variants into libgit and lets the other builtins use this libified run_hook(). The run_hook() function used in receive-pack.c feeds the standard input of the pre-receive or post-receive hooks. This function is renamed to run_receive_hook() because the libified run_hook() cannot handle this. Mentored-by: Daniel Barkalow <barkalow@iabervon.org> Mentored-by: Christian Couder <chriscool@tuxfamily.org> Signed-off-by: Stephan Beyer <s-beyer@gmx.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-10-02run-command.c: remove run_command_v_opt_cd()Libravatar Nanako Shiraishi1-8/+0
This function is not used anywhere. Johannes Sixt <johannes.sixt@telecom.at>: > Future callers can use run_command_v_opt_cd_env() instead. Signed-off-by: Nanako Shiraishi <nanako3@lavabit.com> Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
2008-08-19Merge branch 'jk/pager-swap'Libravatar Junio C Hamano1-0/+2
* jk/pager-swap: spawn pager via run_command interface run-command: add pre-exec callback
2008-08-04Add output flushing before fork()Libravatar Anders Melchiorsen1-0/+1
This adds fflush(NULL) before fork() in start_command(), to keep the generic interface safe. A remaining use of fork() with no flushing is in a comment in show_tree(). Rewrite that comment to use start_command(). Signed-off-by: Anders Melchiorsen <mail@cup.kalibalik.dk> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-08-03Flush output in start_asyncLibravatar Anders Melchiorsen1-0/+3
This prevents double output in case stdout is redirected. Signed-off-by: Anders Melchiorsen <mail@cup.kalibalik.dk> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-07-28run-command (Windows): Run dashless "git <cmd>"Libravatar Steffen Prohaska1-7/+4
We prefer running the dashless form, and POSIX side already does so; we should use it in MinGW's start_command(), too. Signed-off-by: Steffen Prohaska <prohaska@zib.de> Acked-by: Johannes Sixt <johannes.sixt@telecom.at> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-07-25run-command: add pre-exec callbackLibravatar Jeff King1-0/+2
This is a function provided by the caller which is called _after_ the process is forked, but before the spawned program is executed. On platforms (like mingw) where subprocesses are forked and executed in a single call, the preexec callback is simply ignored. This will be used in the following patch to do some setup for 'less' that must happen in the forked child. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-07-07Merge branch 'qq/maint'Libravatar Junio C Hamano1-0/+2
* qq/maint: run_command(): respect GIT_TRACE Conflicts: run-command.c
2008-07-07run_command(): respect GIT_TRACELibravatar Johannes Schindelin1-0/+2
When GIT_TRACE is set, the user is most likely wanting to see an external command that is about to be executed. Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-06-26Windows: Implement a custom spawnve().Libravatar Johannes Sixt1-1/+1
The problem with Windows's own implementation is that it tries to be clever when a console program is invoked from a GUI application: In this case it sometimes automatically allocates a new console window. As a consequence, the IO channels of the spawned program are directed to the console, but the invoking application listens on channels that are now directed to nowhere. In this implementation we use the lowlevel facilities of CreateProcess(), which offers a flag to tell the system not to open a console. As a side effect, only stdin, stdout, and stderr channels will be accessible from C programs that are spawned. Other channels (file handles, pipe handles, etc.) are still inherited by the spawned program, but it doesn't get enough information to access them. Johannes Schindelin integrated path quoting and unified the various *execv* and *spawnv* helpers. Eric Raible suggested to also quote '{'. Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at>
2008-06-26Windows: Implement asynchronous functions as threads.Libravatar Johannes Sixt1-1/+28
In upload-pack we must explicitly close the output channel of rev-list. (On Unix, the channel is closed automatically because process that runs rev-list terminates.) Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at>
2008-06-23Windows: Implement start_command().Libravatar Johannes Sixt1-14/+83
On Windows, we have spawnv() variants to run a child process instead of fork()/exec(). In order to attach pipe ends to stdin, stdout, and stderr, we have to use this idiom: save1 = dup(1); dup2(pipe[1], 1); spawnv(); dup2(save1, 1); close(pipe[1]); assuming that the descriptors created by pipe() are not inheritable. Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at>
2008-03-05run-command: Redirect stderr to a pipe before redirecting stdout to stderrLibravatar Christian Couder1-7/+7
With this patch, in the 'start_command' function after forking we now take care of stderr in the child process before stdout. This way if 'start_command' is called with a 'child_process' argument like this: .err = -1; .stdout_to_stderr = 1; then stderr will be redirected to a pipe before stdout is redirected to stderr. So we can now get the process' stdout from the pipe (as well as its stderr). Earlier such a call would have redirected stdout to stderr before stderr was itself redirected, and therefore stdout would not have followed stderr, which would not have been very useful anyway. Update documentation in 'api-run-command.txt' accordingly. Signed-off-by: Christian Couder <chriscool@tuxfamily.org> Acked-by: Johannes Sixt <johannes.sixt@telecom.at> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-02-23start_command(), if .in/.out > 0, closes file descriptors, not the callersLibravatar Johannes Sixt1-2/+20
Callers of start_command() can set the members .in and .out of struct child_process to a value > 0 to specify that this descriptor is used as the stdin or stdout of the child process. Previously, if start_command() was successful, this descriptor was closed upon return. Here we now make sure that the descriptor is also closed in case of failures. All callers are updated not to close the file descriptor themselves after start_command() was called. Note that earlier run_gpg_verify() of git-verify-tag set .out = 1, which worked because start_command() treated this as a special case, but now this is incorrect because it closes the descriptor. The intent here is to inherit stdout to the child, which is achieved by .out = 0. Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-02-23start_command(), .in/.out/.err = -1: Callers must close the file descriptorLibravatar Johannes Sixt1-6/+0
By setting .in, .out, or .err members of struct child_process to -1, the callers of start_command() can request that a pipe is allocated that talks to the child process and one end is returned by replacing -1 with the file descriptor. Previously, a flag was set (for .in and .out, but not .err) to signal finish_command() to close the pipe end that start_command() had handed out, so it was optional for callers to close the pipe, and many already do so. Now we make it mandatory to close the pipe. Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2007-11-11run-command: Support sending stderr to /dev/nullLibravatar Shawn O. Pearce1-2/+4
Some callers may wish to redirect stderr to /dev/null in some contexts, such as if they are executing a command only to get the exit status and don't want users to see whatever output it may produce as a side-effect of computing that exit status. Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
2007-10-21Add infrastructure to run a function asynchronously.Libravatar Johannes Sixt1-8/+43
This adds start_async() and finish_async(), which runs a function asynchronously. Communication with the caller happens only via pipes. For this reason, this implementation forks off a child process that runs the function. [sp: Style nit fixed by removing unnecessary block on if condition inside of start_async()] Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at> Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
2007-10-21Have start_command() create a pipe to read the stderr of the child.Libravatar Johannes Sixt1-2/+24
This adds another stanza that allocates a pipe that is connected to the child's stderr and that the caller can read from. In order to request this pipe, the caller sets cmd->err to -1. The implementation is not exactly modeled after the stdout case: For stdout the caller can supply an existing file descriptor, but this facility is nowhere needed in the stderr case. Additionally, the caller is required to close cmd->err. Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at> Signed-off-by: Shawn O. Pearce <spearce@spearce.org>