path: root/run-command.h
AgeCommit message (Collapse)Author
2010-03-10Enable threaded async procedures whenever pthreads is availableJohannes Sixt
Signed-off-by: Johannes Sixt <> Signed-off-by: Junio C Hamano <>
2010-03-07Reimplement async procedures using pthreadsJohannes Sixt
On Windows, async procedures have always been run in threads, and the implementation used Windows specific APIs. Rewrite the code to use pthreads. A new configuration option is introduced so that the threaded implementation can also be used on POSIX systems. Since this option is intended only as playground on POSIX, but is mandatory on Windows, the option is not documented. One detail is that on POSIX it is necessary to set FD_CLOEXEC on the pipe handles. On Windows, this is not needed because pipe handles are not inherited to child processes, and the new calls to set_cloexec() are effectively no-ops. Signed-off-by: Johannes Sixt <> Signed-off-by: Junio C Hamano <>
2010-02-06Merge branch 'sp/maint-push-sideband' into sp/push-sidebandJunio C Hamano
* 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
2010-02-06run-command: support custom fd-set in asyncErik Faye-Lund
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 <> Signed-off-by: Shawn O. Pearce <> Signed-off-by: Junio C Hamano <>
2010-02-06run-command: Allow stderr to be a caller supplied pipeShawn O. Pearce
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 <> Signed-off-by: Junio C Hamano <>
2010-01-02run-command: add "use shell" optionJeff King
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 <> Signed-off-by: Junio C Hamano <>
2009-09-19Test for WIN32 instead of __MINGW32_Frank Li
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 <> Signed-off-by: Marius Storm-Olsen <> Acked-by: Johannes Sixt <> Signed-off-by: Junio C Hamano <>
2009-07-06run_command: report failure to execute the program, but optionally don'tJohannes Sixt
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 <> Signed-off-by: Junio C Hamano <>
2009-07-06run_command: report system call errors instead of returning error codesJohannes Sixt
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 <> Signed-off-by: Junio C Hamano <>
2009-07-05run_command: return exit code as positive valueJohannes Sixt
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 <> Signed-off-by: Junio C Hamano <>
2009-04-01fix portability problem with IS_RUN_COMMAND_ERRJeff King
Some old versions of gcc don't seem to like us negating an enum constant. Let's work around it by negating the other half of the comparison instead. Reported by Pierre Poissinger on gcc 2.9. Signed-off-by: Junio C Hamano <>
2009-02-03Merge branch 'jk/maint-cleanup-after-exec-failure'Junio C Hamano
* 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(): help callers distinguish errorsJeff King
run_command() returns a single integer specifying either an error code or the exit status of the spawned program. The only way to tell the difference is that the error codes are outside of the allowed range of exit status values. Rather than make each caller implement the test against a magic limit, let's provide a macro. Signed-off-by: Jeff King <> Signed-off-by: Junio C Hamano <>
2009-01-18Move run_hook() from builtin-commit.c into run-command.c (libgit)Stephan Beyer
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 <> Mentored-by: Christian Couder <> Signed-off-by: Stephan Beyer <> Signed-off-by: Junio C Hamano <>
2008-10-03run-command.c: remove run_command_v_opt_cd()Nanako Shiraishi
This function is not used anywhere. Johannes Sixt <>: > Future callers can use run_command_v_opt_cd_env() instead. Signed-off-by: Nanako Shiraishi <> Signed-off-by: Shawn O. Pearce <>
2008-07-26run-command: add pre-exec callbackJeff King
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 <> Signed-off-by: Junio C Hamano <>
2008-06-26Windows: Implement asynchronous functions as threads.Johannes Sixt
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 <>
2008-02-23start_command(), if .in/.out > 0, closes file descriptors, not the callersJohannes Sixt
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 <> Signed-off-by: Junio C Hamano <>
2008-02-23start_command(), .in/.out/.err = -1: Callers must close the file descriptorJohannes Sixt
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 <> Signed-off-by: Junio C Hamano <>
2007-11-12run-command: Support sending stderr to /dev/nullShawn O. Pearce
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 <>
2007-10-21Add infrastructure to run a function asynchronously.Johannes Sixt
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 <> Signed-off-by: Shawn O. Pearce <>
2007-10-21Have start_command() create a pipe to read the stderr of the child.Johannes Sixt
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 <> Signed-off-by: Shawn O. Pearce <>
2007-05-24Allow environment variables to be unset in the processes started by run_commandAlex Riesen
To unset a variable, just specify its name, without "=". For example: const char *env[] = {"GIT_DIR=.git", "PWD", NULL}; const char *argv[] = {"git-ls-files", "-s", NULL}; int err = run_command_v_opt_cd_env(argv, RUN_GIT_CMD, ".", env); The PWD will be unset before executing git-ls-files. Signed-off-by: Alex Riesen <> Signed-off-by: Junio C Hamano <>
2007-05-24Add ability to specify environment extension to run_commandAlex Riesen
There is no way to specify and override for the environment: there'd be no user for it yet. Signed-off-by: Alex Riesen <> Signed-off-by: Junio C Hamano <>
2007-05-24Add run_command_v_opt_cd: chdir into a directory before execAlex Riesen
It can make code simplier (no need to preserve cwd) and safer (no chance the cwd of the current process is accidentally forgotten). Signed-off-by: Alex Riesen <> Signed-off-by: Junio C Hamano <>
2007-03-13Teach run-command to redirect stdout to /dev/nullShawn O. Pearce
Some run-command callers may wish to just discard any data that is sent to stdout from the child. This is a lot like our existing no_stdin support, we just open /dev/null and duplicate the descriptor into position. Signed-off-by: Shawn O. Pearce <> Signed-off-by: Junio C Hamano <>
2007-03-13Teach run-command about stdout redirectionShawn O. Pearce
Some potential callers of the run_command family of functions need to control not only the stdin redirection of the child, but also the stdout redirection of the child. This can now be setup much like the already existing stdin redirection. Signed-off-by: Shawn O. Pearce <> Signed-off-by: Junio C Hamano <>
2007-03-12Teach run_command how to setup a stdin pipeShawn O. Pearce
Sometimes callers trying to use run_command to execute a child process will want to setup a pipe or file descriptor to redirect into the child's stdin. This idea is completely stolen from builtin-bundle's fork_with_pipe, written by Johannes Schindelin. All credit (and blame) should lie with Dscho. ;-) Signed-off-by: Shawn O. Pearce <> Signed-off-by: Junio C Hamano <>
2007-03-12Split run_command into two halves (start/finish)Shawn O. Pearce
If the calling process wants to send data to stdin of a child process it will need to arrange for a pipe and get the child process running, feed data to it, then wait for the child process to finish. So we split the run function into two halves, allowing callers to first start the child then later finish it. Signed-off-by: Shawn O. Pearce <> Signed-off-by: Junio C Hamano <>
2007-03-12Start defining a more sophisticated run_commandShawn O. Pearce
There are a number of places where we do some variation of fork()+exec() but we also need to setup redirection in the process, much like what run_command does for us already with its option flags. It would be nice to reuse more of the run_command logic, especially as that non-fork API helps us to port to odd platforms like Win32. Signed-off-by: Shawn O. Pearce <> Signed-off-by: Junio C Hamano <>
2007-03-12Remove unused run_command variantsShawn O. Pearce
We don't actually use these va_list based variants of run_command anymore. I'm removing them before I make further improvements. Signed-off-by: Shawn O. Pearce <> Signed-off-by: Junio C Hamano <>
2006-12-31Use /dev/null for update hook stdin.Shawn O. Pearce
Currently the update hook invoked by receive-pack has its stdin connected to the pushing client. The hook shouldn't attempt to read from this stream, and doing so may consume data that was meant for receive-pack. Instead we should give the update hook /dev/null as its stdin, ensuring that it always receives EOF and doesn't disrupt the protocol if it attempts to read any data. The post-update hook is similar, as it gets invoked with /dev/null on stdin to prevent the hook from reading data from the client. Previously we had invoked it with stdout also connected to /dev/null, throwing away anything on stdout, to prevent client protocol errors. Instead we should redirect stdout to stderr, like we do with the update hook. Signed-off-by: Shawn O. Pearce <> Signed-off-by: Junio C Hamano <>
2006-12-31Redirect update hook stdout to stderr.Shawn O. Pearce
If an update hook outputs to stdout then that output will be sent back over the wire to the push client as though it were part of the git protocol. This tends to cause protocol errors on the client end of the connection, as the hook output is not expected in that context. Most hook developers work around this by making sure their hook outputs everything to stderr. But hooks shouldn't need to perform such special behavior. Instead we can just dup stderr to stdout prior to invoking the update hook. Signed-off-by: Shawn O. Pearce <> Signed-off-by: Junio C Hamano <>
2006-12-31Remove unnecessary argc parameter from run_command_v.Shawn O. Pearce
The argc parameter is never used by the run_command_v family of functions. Instead they require that the passed argv[] be NULL terminated so they can rely on the operating system's execvp function to correctly pass the arguments to the new process. Making the caller pass the argc is just confusing, as the caller could be mislead into believing that the argc might take precendece over the argv, or that the argv does not need to be NULL terminated. So goodbye argc. Don't come back. Signed-off-by: Shawn O. Pearce <> Signed-off-by: Junio C Hamano <>
2006-03-05Const tightening.Junio C Hamano
Mark Wooding noticed there was a type mismatch warning in git.c; this patch does things slightly differently (mostly tightening const) and was what I was holding onto, waiting for the setup-revisions change to be merged into the master branch. Signed-off-by: Junio C Hamano <>
2006-01-14Exec git programs without using PATH.Michal Ostrowski
The git suite may not be in PATH (and thus programs such as git-send-pack could not exec git-rev-list). Thus there is a need for logic that will locate these programs. Modifying PATH is not desirable as it result in behavior differing from the user's intentions, as we may end up prepending "/usr/bin" to PATH. - git C programs will use exec*_git_cmd() APIs to exec sub-commands. - exec*_git_cmd() will execute a git program by searching for it in the following directories: 1. --exec-path (as used by "git") 2. The GIT_EXEC_PATH environment variable. 3. $(gitexecdir) as set in Makefile (default value $(bindir)). - git wrapper will modify PATH as before to enable shell scripts to invoke "git-foo" commands. Ideally, shell scripts should use the git wrapper to become independent of PATH, and then modifying PATH will not be necessary. [jc: with minor updates after a brief review.] Signed-off-by: Michal Ostrowski <> Signed-off-by: Junio C Hamano <>
2005-12-08Clean up file descriptors when calling hooks.Daniel Barkalow
When calling post-update hook, don't leave stdin and stdout connected to the pushing connection. Signed-off-by: Daniel Barkalow <> Signed-off-by: Junio C Hamano <>
2005-08-03receive-pack hooks updates.Junio C Hamano
The earlier one conflated update and post-update hooks for no good reason. Correct that ugly hack. Now post-update hooks will take the list of successfully updated refs. Signed-off-by: Junio C Hamano <>
2005-08-01[PATCH] Added hook in git-receive-packJosef Weidendorfer
Just before updating a ref, $GIT_DIR/hooks/update refname old-sha1 new-sha1 is called if executable. The hook can decline the ref to be updated by exiting with a non-zero status, or allow it to be updated by exiting with a zero status. The mechanism also allows e.g sending of a mail with pushed commits on the remote repository. Documentation update with an example hook is included. jc: The credits of the basic idea and initial implementation go to Josef, but I ended up rewriting major parts of his patch, so bugs are all mine. Also I changed the semantics for the hook from his original version (which were post-update hook) so that the hook can optionally decline to update the ref, and also can be used to implement the overall cleanups. The latter was primarily to implement a suggestion from Linus that calling update-server-info should be made optional. Signed-off-by: Junio C Hamano <>