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@wxwidgets.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 #include <fcntl.h>
  17
  18 #include "wx/log.h"
  19 #include "wx/intl.h"
  20
  21 // ----------------------------------------------------------------------------
  22 // wxPipe: this class encapsulates pipe() system call
  23 // ----------------------------------------------------------------------------
  24
  25 class wxPipe
  26 {
  27 public:
  28     // the symbolic names for the pipe ends
  29     enum Direction
  30     {
  31         Read,
  32         Write
  33     };
  34
  35     enum
  36     {
  37         INVALID_FD = -1
  38     };
  39
  40     // default ctor doesn't do anything
  41     wxPipe() { m_fds[Read] = m_fds[Write] = INVALID_FD; }
  42
  43     // create the pipe, return TRUE if ok, FALSE on error
  44     bool Create()
  45     {
  46         if ( pipe(m_fds) == -1 )
  47         {
  48             wxLogSysError(_("Pipe creation failed"));
  49
  50             return false;
  51         }
  52
  53         return true;
  54     }
  55
  56     // switch the given end of the pipe to non-blocking IO
  57     bool MakeNonBlocking(Direction which)
  58     {
  59         const int flags = fcntl(m_fds[which], F_GETFL, 0);
  60         if ( flags == -1 )
  61             return false;
  62
  63         return fcntl(m_fds[which], F_SETFL, flags | O_NONBLOCK) == 0;
  64     }
  65
  66     // return TRUE if we were created successfully
  67     bool IsOk() const { return m_fds[Read] != INVALID_FD; }
  68
  69     // return the descriptor for one of the pipe ends
  70     int operator[](Direction which) const { return m_fds[which]; }
  71
  72     // detach a descriptor, meaning that the pipe dtor won't close it, and
  73     // return it
  74     int Detach(Direction which)
  75     {
  76         int fd = m_fds[which];
  77         m_fds[which] = INVALID_FD;
  78
  79         return fd;
  80     }
  81
  82     // close the pipe descriptors
  83     void Close()
  84     {
  85         for ( size_t n = 0; n < WXSIZEOF(m_fds); n++ )
  86         {
  87             if ( m_fds[n] != INVALID_FD )
  88             {
  89                 close(m_fds[n]);
  90                 m_fds[n] = INVALID_FD;
  91             }
  92         }
  93     }
  94
  95     // dtor closes the pipe descriptors
  96     ~wxPipe() { Close(); }
  97
  98 private:
  99     int m_fds[2];
 100 };
 101
 102 #endif // _WX_UNIX_PIPE_H_
 103