ACE/examples/APG/Processes/Spawn.cpp

   1 #include "ace/OS_NS_stdio.h"
   2 #include "ace/OS_NS_fcntl.h"
   3 #include "ace/OS_NS_pwd.h"
   4 #include "ace/os_include/os_pwd.h"
   5 #include "ace/OS_NS_stdlib.h"
   6 #include "ace/OS_NS_string.h"
   7 #include "ace/OS_NS_unistd.h"
   8 #include "ace/OS_NS_pwd.h"
   9 #include "ace/Process.h"
  10 #include "ace/Log_Msg.h"
  11
  12 // Listing 1 code/ch10
  13 class Manager : public ACE_Process
  14 {
  15 public:
  16   Manager (const ACE_TCHAR* program_name)
  17   {
  18     ACE_TRACE ("Manager::Manager");
  19     ACE_OS::strcpy (programName_, program_name);
  20   }
  21
  22   int doWork ()
  23   {
  24     ACE_TRACE ("Manager::doWork");
  25
  26     // Spawn the new process; prepare() hook is called first.
  27     ACE_Process_Options options;
  28     pid_t pid = this->spawn (options);
  29     if (pid == ACE_INVALID_PID)
  30       ACE_ERROR_RETURN((LM_ERROR, ACE_TEXT ("%p\n"),
  31                         ACE_TEXT ("spawn")), -1);
  32
  33     // Wait forever for my child to exit.
  34     if (this->wait () == -1)
  35       ACE_ERROR_RETURN ((LM_ERROR, ACE_TEXT ("%p\n"),
  36                          ACE_TEXT ("wait")), -1);
  37
  38     // Dump whatever happened.
  39     this->dumpRun ();
  40     return 0;
  41   }
  42 // Listing 1
  43
  44 private:
  45   // Listing 3 code/ch10
  46   int dumpRun ()
  47   {
  48     ACE_TRACE ("Manager::dumpRun");
  49
  50     if (ACE_OS::lseek (this->outputfd_, 0, SEEK_SET) == -1)
  51       ACE_ERROR_RETURN ((LM_ERROR, ACE_TEXT ("%p\n"),
  52                          ACE_TEXT ("lseek")), -1);
  53
  54     char buf[1024];
  55     ssize_t length = 0;
  56
  57     // Read the contents of the error stream written
  58     // by the child and print it out.
  59     while ((length = ACE_OS::read (this->outputfd_,
  60                                    buf, sizeof(buf)-1)) > 0)
  61       {
  62         buf[length] = 0;
  63         ACE_DEBUG ((LM_DEBUG, ACE_TEXT ("%C\n"), buf));
  64       }
  65
  66     ACE_OS::close (this->outputfd_);
  67     return 0;
  68   }
  69  // Listing 3
  70
  71  // Listing 2 code/ch10
  72   // prepare() is inherited from ACE_Process.
  73   int prepare (ACE_Process_Options &options)
  74   {
  75     ACE_TRACE ("Manager::prepare");
  76
  77     options.command_line (ACE_TEXT ("%s 1"), this->programName_);
  78     if (this->setStdHandles (options) == -1 ||
  79         this->setEnvVariable (options) == -1)
  80       return -1;
  81 #if !defined (ACE_WIN32) && !defined (ACE_LACKS_PWD_FUNCTIONS)
  82     return this->setUserID (options);
  83 #else
  84     return 0;
  85 #endif
  86   }
  87
  88   int setStdHandles (ACE_Process_Options &options)
  89   {
  90     ACE_TRACE ("Manager::setStdHandles");
  91
  92     ACE_OS::unlink ("output.dat");
  93     this->outputfd_ =
  94       ACE_OS::open ("output.dat", O_RDWR | O_CREAT);
  95     return options.set_handles
  96       (ACE_STDIN, ACE_STDOUT, this->outputfd_);
  97   }
  98
  99   int setEnvVariable (ACE_Process_Options &options)
 100   {
 101     ACE_TRACE ("Manager::setEnvVariables");
 102     return options.setenv
 103       (ACE_TEXT ("PRIVATE_VAR=/that/seems/to/be/it"));
 104   }
 105  // Listing 2
 106
 107 #if !defined (ACE_LACKS_PWD_FUNCTIONS)
 108  // Listing 10 code/ch10
 109   int setUserID (ACE_Process_Options &options)
 110   {
 111     ACE_TRACE ("Manager::setUserID");
 112     passwd* pw = ACE_OS::getpwnam ("nobody");
 113     if (pw == 0)
 114       return -1;
 115     options.seteuid (pw->pw_uid);
 116     return 0;
 117   }
 118  // Listing 10
 119 #endif /* !ACE_LACKS_PWD_FUNCTIONS */
 120
 121 private:
 122   ACE_HANDLE outputfd_;
 123   ACE_TCHAR programName_[256];
 124 };
 125
 126 // Listing 4 code/ch10
 127 class Slave
 128 {
 129 public:
 130   Slave ()
 131   {
 132     ACE_TRACE ("Slave::Slave");
 133   }
 134
 135   int doWork ()
 136   {
 137     ACE_TRACE ("Slave::doWork");
 138
 139     ACE_DEBUG ((LM_INFO,
 140                 ACE_TEXT ("(%P) started at %T, parent is %d\n"),
 141                 ACE_OS::getppid ()));
 142     this->showWho ();
 143     ACE_DEBUG ((LM_INFO,
 144                 ACE_TEXT ("(%P) the private environment is %s\n"),
 145                 ACE_OS::getenv ("PRIVATE_VAR")));
 146
 147     ACE_TCHAR str[128];
 148     ACE_OS::sprintf (str, ACE_TEXT ("(%d) Enter your command\n"),
 149                      static_cast<int>(ACE_OS::getpid ()));
 150     ACE_OS::write (ACE_STDOUT, str, ACE_OS::strlen (str));
 151     this->readLine (str);
 152     ACE_DEBUG ((LM_DEBUG, ACE_TEXT ("(%P) Executed: %C\n"),
 153                 str));
 154     return 0;
 155   }
 156 // Listing 4
 157
 158   void showWho ()
 159   {
 160     ACE_TRACE ("Slave::showWho");
 161 #if !defined (ACE_LACKS_PWD_FUNCTIONS)
 162     passwd *pw = ::getpwuid (ACE_OS::geteuid ());
 163     ACE_DEBUG ((LM_INFO,
 164                 ACE_TEXT ("(%P) Running this process as:%s\n"),
 165                 pw->pw_name));
 166 #endif
 167   }
 168
 169   ACE_TCHAR* readLine (ACE_TCHAR* str)
 170   {
 171     ACE_TRACE ("Slave::readLine");
 172
 173     int i = 0;
 174     while (true)
 175       {
 176         ssize_t retval = ACE_OS::read (ACE_STDIN, &str[i], 1);
 177         if (retval > 0)
 178           {
 179             if (str[i] == '\n')
 180               {
 181                 str[++i] = 0;
 182                 return str;
 183               }
 184             i++;
 185           }
 186         else
 187           return str;
 188       }
 189   }
 190 };
 191
 192 // Listing 0 code/ch10
 193 int ACE_TMAIN (int argc, ACE_TCHAR *argv[])
 194 {
 195   if (argc > 1)   // Slave mode
 196     {
 197       Slave s;
 198       return s.doWork ();
 199     }
 200
 201   // Else, Master mode
 202   Manager m (argv[0]);
 203   return m.doWork ();
 204 }
 205 // Listing 0