Most I/O objects have an associated status value encapsulated by the os_io_status class. By using this class, you can obtain and modify the characteristics of an I/O object, such as its user and group.

The following example shows both methods of obtaining the os_io_status for an os_file .

Example <ospace/file/examples/iostat1.cpp>


  #include <iostream>
#include <ospace/file.h>
#include <ospace/io.h>
#include <ospace/security.h>

const char* path = "/tmp/tmp.txt";

void
main()
  {
  os_file_toolkit init_file;
  os_security_toolkit init_security;

  os_file file( path, O_CREAT | O_TRUNC, O_WRONLY );
  file.write( "junk", 4 );

  os_io_status status( path );
  cout << "group = " << os_group( status.group() ) << endl;
  cout << "user = " << os_user( status.user() ) << endl;

  os_io_status status2 = file.status();
  cout << "size = " << status2.size() << endl;
  }

group = os_group( bigred, 100 )
user = os_user( wku, 200 )
size = 4

Once you have an os_io_status object, you can send it functions to modify its attributes. Not all attributes can be altered.

The following example shows how to alter the mode of a file using os_io_status on a UNIX machine.

Example <ospace/io/examples/iostat2.cpp>


  #include <iostream>
#include <ospace/file.h>
#include <ospace/io.h>

const char* path = "/tmp/tmp.txt";

void
main()
  {
  os_file_toolkit initialize;

  os_file_system::remove_if_exists( path ); // Remove existing file.

  os_file file( path, O_CREAT | O_TRUNC, O_WRONLY, 0644 );
  file.write( "junk", 4 );

  os_io_status status( path );
  cout << "mode = " << os_mode( status.mode() ) << endl;
  cout << "Changing file mode to 0600" << endl;
  status.mode( 0600 );
  cout << "New mode = " << os_mode( os_io_status( path ).mode() );
  cout << endl;
  }

mode = -rw-r--r--
Changing file mode to 0600
New mode = -rw-------

Refer to the dir4.cpp example in File<ToolKit> for another example using the os_io_status class.