Initial commit

Torque/SDK/engine/platformX86UNIX/x86UNIXUtils.cc

@@ -0,0 +1,269 @@
+//-----------------------------------------------------------------------------
+// Torque Game Engine 
+// Copyright (C) GarageGames.com, Inc.
+//-----------------------------------------------------------------------------
+
+
+
+#include <unistd.h>
+#include <termios.h>
+#include <stdio.h>
+#include <sys/utsname.h>
+
+// for UnixCommandExecutor
+#include <fcntl.h>
+#include <errno.h>
+#include <sys/wait.h>
+#include <stdlib.h>
+
+#include "platformX86UNIX/platformX86UNIX.h"
+#include "platformX86UNIX/x86UNIXUtils.h"
+
+UnixUtils *UUtils = NULL;
+UnixUtils utils; 
+
+UnixUtils::UnixUtils()
+{
+   UUtils = this;
+
+   mUnameInfo = (struct utsname*)dRealMalloc(sizeof(struct utsname));;
+   if (uname(mUnameInfo) == -1)
+   {
+      // oh well
+      dRealFree(mUnameInfo);
+      mUnameInfo = NULL;
+   }
+}
+
+UnixUtils::~UnixUtils()
+{
+   if (mUnameInfo != NULL)
+   {
+      dRealFree(mUnameInfo);
+      mUnameInfo = NULL;
+   }
+}
+
+const char* UnixUtils::getOSName()
+{
+   if (mUnameInfo == NULL)
+      return "";
+
+   return mUnameInfo->sysname;  
+}
+
+bool UnixUtils::inBackground()
+{
+   int terminalGroupId = tcgetpgrp(fileno(stdin));
+   int myPid = getpid();
+   if (terminalGroupId != myPid)
+      return true;
+   else
+      return false;
+}
+
+//-----------------------------------------------------------------------------
+// UnixCommandExecutor 
+void UnixCommandExecutor::clearFields()
+{
+   mRet = -1;
+   mStdoutSave = -1;
+   mStderrSave = -1;
+   mPipeFiledes[0] = -1;
+   mPipeFiledes[1] = -1;
+   mChildPID = -1;
+   mBytesRead = 0;
+   mStdoutClosed = false;
+   mStderrClosed = false;
+   mChildExited = false;
+}
+
+UnixCommandExecutor::UnixCommandExecutor()
+{
+   clearFields();
+}
+
+UnixCommandExecutor::~UnixCommandExecutor()
+{
+   cleanup();
+}
+
+int UnixCommandExecutor::exec(char* args[], 
+                              char* stdoutCapture, int stdoutCaptureSize)
+{
+   // check for shitty parameters
+   if (args == NULL || stdoutCapture == NULL || 
+       stdoutCaptureSize <= 0)
+      return -666;
+
+   // we're going to be redirecting stdout, so save it so that we can 
+   // restore it
+   mRet = dup(1);
+   if (mRet == -1)
+   {
+      cleanup();
+      return mRet;
+   }
+   mStdoutSave = mRet;
+
+   // save stderr
+   mRet = dup(2);
+   if (mRet == -1)
+   {
+      cleanup();
+      return mRet;
+   }
+   mStderrSave = mRet;
+
+   // we'll need some pipe action for communicating with subprocess
+   mRet = pipe(mPipeFiledes);
+   if (mRet == -1)
+   {
+      cleanup();
+      return mRet;
+   }
+
+   // close stdout
+   mRet = close(1);
+   if (mRet == -1)
+   {
+      cleanup();
+      return mRet;
+   }
+   mStdoutClosed = true;
+
+   // stderr just gets closed and the output discarded
+   mRet = close(2);
+   if (mRet == -1)
+   {
+      cleanup();
+      return mRet;
+   }
+   mStderrClosed = true;
+
+   // dup the pipe output into stdout
+   mRet = dup2(mPipeFiledes[1], 1);
+   if (mRet == -1)
+   {
+      cleanup();
+      return mRet;
+   }
+
+   // fork
+   mRet = fork();
+   if (mRet == -1)
+   {
+      cleanup();
+      return mRet;
+   }
+         
+   if (mRet == 0)
+   {
+      // child process
+
+      //close(mPipeFiledes[0]);
+      mRet = execvp(args[0], args);
+      // if exec returns, some bad shit went down, so just
+      // get outta here
+      exit(mRet);
+   }
+
+   // parent process
+   mChildPID = mRet;
+
+   // need to suck in data from pipe while child is running, 
+   // otherwise child will eventually block on write and we'll
+   // wait forever
+   memset(stdoutCapture, 0, stdoutCaptureSize);
+
+   // set input to be non blocking so that we don't block on read
+   mRet = fcntl(mPipeFiledes[0], F_SETFL, O_NONBLOCK);
+   if (mRet == -1)
+   {
+      cleanup();
+      return mRet;
+   }
+
+   // check to see if child has exited
+   mRet = waitpid(mChildPID, NULL, WNOHANG);
+   while (mRet == 0)
+   {
+      // not exited, read some data
+      mRet = read(mPipeFiledes[0], stdoutCapture + mBytesRead, 
+                  stdoutCaptureSize - mBytesRead);
+      // any error that isn't EAGAIN means we should exit
+      if (mRet == -1 && errno != EAGAIN)
+      {
+         cleanup();
+         return mRet;
+      }
+
+      // if the read was ok, increment bytes read
+      if (mRet != -1)
+         mBytesRead += mRet;
+
+      // check again for child exit
+      mRet = waitpid(mChildPID, NULL, WNOHANG);    
+   }
+
+   // check for error from waitpid
+   if (mRet == -1 && errno != ECHILD)
+   {
+      cleanup();
+      return mRet;
+   }
+
+   // if we get here, the child exited
+   mChildExited = true;
+
+   // read final bit of data
+   mRet = read(mPipeFiledes[0], stdoutCapture + mBytesRead, 
+               stdoutCaptureSize - mBytesRead);
+   if (mRet == -1 && errno != EAGAIN)
+   {
+      cleanup();
+      return mRet;
+   }
+
+   if (mRet != -1)
+      mBytesRead += mRet;
+
+   // done...cleanup
+   cleanup();
+
+   return 0;
+}
+
+void UnixCommandExecutor::cleanup()
+{
+   // if child spawned and not exited, wait
+   if (mChildPID > 0 && !mChildExited)
+      waitpid(mChildPID, NULL, 0);
+   // close pipe descriptors
+   if (mPipeFiledes[0] != -1)
+      close(mPipeFiledes[0]);
+   if (mPipeFiledes[1] != -1)
+      close(mPipeFiledes[1]);
+   // if stdout is redirected, restore it
+   if (mStdoutClosed && mStdoutSave != -1)
+      dup2(mStdoutSave, 1);
+   // close stdout save descriptor
+   if (mStdoutSave != -1)
+      close(mStdoutSave);
+   // if stderr is redirected, restore it
+   if (mStderrClosed && mStderrSave != -1)
+      dup2(mStderrSave, 2);
+   // close stderr save descriptor
+   if (mStderrSave != -1)
+      close(mStderrSave);
+
+   clearFields();
+}
+
+/* Usage:
+   UnixCommandExecutor exec;
+   char* args[] = { "ps", "-aux", NULL };
+   char data[20000];
+   int ret = exec.exec(args, data, sizeof(data));
+   printf("%s", data);
+*/