include/wx/unix/pipe.h

   1 ///////////////////////////////////////////////////////////////////////////////
   2 // Name:        wx/unix/pipe.h
   3 // Purpose:     wxPipe class
   4 // Author:      Vadim Zeitlin
   5 // Modified by:
   6 // Created:     24.06.2003 (extracted from src/unix/utilsunx.cpp)
   7 // RCS-ID:      $Id$
   8 // Copyright:   (c) 2003 Vadim Zeitlin <vadim@wxwindows.org>
   9 // Licence:     wxWindows licence
  10 ///////////////////////////////////////////////////////////////////////////////
  11
  12 #ifndef _WX_UNIX_PIPE_H_
  13 #define _WX_UNIX_PIPE_H_
  14
  15 #include <unistd.h>
  16
  17 // ----------------------------------------------------------------------------
  18 // wxPipe: this class encapsulates pipe() system call
  19 // ----------------------------------------------------------------------------
  20
  21 class wxPipe
  22 {
  23 public:
  24     // the symbolic names for the pipe ends
  25     enum Direction
  26     {
  27         Read,
  28         Write
  29     };
  30
  31     enum
  32     {
  33         INVALID_FD = -1
  34     };
  35
  36     // default ctor doesn't do anything
  37     wxPipe() { m_fds[Read] = m_fds[Write] = INVALID_FD; }
  38
  39     // create the pipe, return TRUE if ok, FALSE on error
  40     bool Create()
  41     {
  42         if ( pipe(m_fds) == -1 )
  43         {
  44             wxLogSysError(_("Pipe creation failed"));
  45
  46             return FALSE;
  47         }
  48
  49         return TRUE;
  50     }
  51
  52     // return TRUE if we were created successfully
  53     bool IsOk() const { return m_fds[Read] != INVALID_FD; }
  54
  55     // return the descriptor for one of the pipe ends
  56     int operator[](Direction which) const
  57     {
  58         wxASSERT_MSG( which >= 0 && (size_t)which < WXSIZEOF(m_fds),
  59                       _T("invalid pipe index") );
  60
  61         return m_fds[which];
  62     }
  63
  64     // detach a descriptor, meaning that the pipe dtor won't close it, and
  65     // return it
  66     int Detach(Direction which)
  67     {
  68         wxASSERT_MSG( which >= 0 && (size_t)which < WXSIZEOF(m_fds),
  69                       _T("invalid pipe index") );
  70
  71         int fd = m_fds[which];
  72         m_fds[which] = INVALID_FD;
  73
  74         return fd;
  75     }
  76
  77     // close the pipe descriptors
  78     void Close()
  79     {
  80         for ( size_t n = 0; n < WXSIZEOF(m_fds); n++ )
  81         {
  82             if ( m_fds[n] != INVALID_FD )
  83                 close(m_fds[n]);
  84         }
  85     }
  86
  87     // dtor closes the pipe descriptors
  88     ~wxPipe() { Close(); }
  89
  90 private:
  91     int m_fds[2];
  92 };
  93
  94 #endif // _WX_UNIX_PIPE_H_
  95