/*
- * Copyright 2013 Facebook, Inc.
+ * Copyright 2014 Facebook, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* // read from proc.stdout()
* proc.wait();
*
- * A thread-safe version of popen() (type="w", to write from the child):
+ * A thread-safe version of popen() (type="w", to write to the child):
* Subprocess proc(cmd, Subprocess::pipeStdin());
* // write to proc.stdin()
* proc.wait();
#include <sys/types.h>
#include <signal.h>
+#if __APPLE__
+#include <sys/wait.h>
+#else
#include <wait.h>
+#endif
#include <exception>
#include <vector>
#include <boost/operators.hpp>
#include <boost/noncopyable.hpp>
-#include "folly/io/IOBufQueue.h"
-#include "folly/MapUtil.h"
-#include "folly/Portability.h"
-#include "folly/Range.h"
+#include <folly/io/IOBufQueue.h>
+#include <folly/MapUtil.h>
+#include <folly/Portability.h>
+#include <folly/Range.h>
namespace folly {
public:
Options()
: closeOtherFds_(false),
- usePath_(false),
- parentDeathSignal_(0) {
+ usePath_(false) {
}
/**
*/
Options& usePath() { usePath_ = true; return *this; }
+ /**
+ * Change the child's working directory, after the vfork.
+ */
+ Options& chdir(const std::string& dir) { childDir_ = dir; return *this; }
+
+#if __linux__
/**
* Child will receive a signal when the parent exits.
*/
parentDeathSignal_ = sig;
return *this;
}
+#endif
/**
* Helpful way to combine Options.
FdMap fdActions_;
bool closeOtherFds_;
bool usePath_;
- int parentDeathSignal_;
+ std::string childDir_; // "" keeps the parent's working directory
+#if __linux__
+ int parentDeathSignal_{0};
+#endif
};
static Options pipeStdin() { return Options().stdin(PIPE); }
* If stdout or stderr is not a pipe, an empty IOBuf queue will be returned
* for the respective buffer.
*
- * Note that communicate() returns when all pipes to/from the child are
- * closed; the child might stay alive after that, so you must still wait().
+ * Note that communicate() and communicateIOBuf() both return when all
+ * pipes to/from the child are closed; the child might stay alive after
+ * that, so you must still wait().
+ *
+ * communicateIOBuf() uses IOBufQueue for buffering (which has the
+ * advantage that it won't try to allocate all data at once), but it does
+ * store the subprocess's entire output in memory before returning.
*
- * communicateIOBuf uses IOBufQueue for buffering (which has the advantage
- * that it won't try to allocate all data at once). communicate
- * uses strings for simplicity.
+ * communicate() uses strings for simplicity.
*/
std::pair<IOBufQueue, IOBufQueue> communicateIOBuf(
IOBufQueue input = IOBufQueue());
typedef std::function<bool(int, int)> FdCallback;
void communicate(FdCallback readCallback, FdCallback writeCallback);
+ /**
+ * Enable notifications (callbacks) for one pipe to/from child. By default,
+ * all are enabled. Useful for "chatty" communication -- you want to disable
+ * write callbacks until you receive the expected message.
+ */
+ void enableNotifications(int childFd, bool enabled);
+
+ /**
+ * Are notifications for one pipe to/from child enabled?
+ */
+ bool notificationsEnabled(int childFd) const;
+
/**
* Return the child's pid, or -1 if the child wasn't successfully spawned
* or has already been wait()ed upon.
// so we're happy with a vector here, even if it means linear erase.
// sorted by childFd
struct PipeInfo : private boost::totally_ordered<PipeInfo> {
- int parentFd;
- int childFd;
- int direction; // one of PIPE_IN / PIPE_OUT
+ int parentFd = -1;
+ int childFd = -1;
+ int direction = PIPE_IN; // one of PIPE_IN / PIPE_OUT
+ bool enabled = true;
+
bool operator<(const PipeInfo& other) const {
return childFd < other.childFd;
}