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
  17 #include "wx/log.h"
  18 #include "wx/intl.h"
  19
  20 // ----------------------------------------------------------------------------
  21 // wxPipe: this class encapsulates pipe() system call
  22 // ----------------------------------------------------------------------------
  23
  24 class wxPipe
  25 {
  26 public:
  27     // the symbolic names for the pipe ends
  28     enum Direction
  29     {
  30         Read,
  31         Write,
  32         Direction_Max
  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     // return TRUE if we were created successfully
  57     bool IsOk() const { return m_fds[Read] != INVALID_FD; }
  58
  59     // return the descriptor for one of the pipe ends
  60     int operator[](Direction which) const { return m_fds[which]; }
  61
  62     // detach a descriptor, meaning that the pipe dtor won't close it, and
  63     // return it
  64     int Detach(Direction which)
  65     {
  66         int fd = m_fds[which];
  67         m_fds[which] = INVALID_FD;
  68
  69         return fd;
  70     }
  71
  72     // close the pipe descriptors
  73     void Close()
  74     {
  75         for ( size_t n = 0; n < WXSIZEOF(m_fds); n++ )
  76         {
  77             if ( m_fds[n] != INVALID_FD )
  78                 close(m_fds[n]);
  79         }
  80     }
  81
  82     // dtor closes the pipe descriptors
  83     ~wxPipe() { Close(); }
  84
  85 private:
  86     int m_fds[Direction_Max];
  87 };
  88
  89 #if wxUSE_STREAMS
  90
  91 #include "wx/wfstream.h"
  92
  93 // ----------------------------------------------------------------------------
  94 // wxPipeInputStream: stream for reading from a pipe
  95 // ----------------------------------------------------------------------------
  96
  97 class wxPipeInputStream : public wxFileInputStream
  98 {
  99 public:
 100     wxPipeInputStream(int fd) : wxFileInputStream(fd) { }
 101
 102     // return TRUE if the pipe is still opened
 103     bool IsOpened() const { return !Eof(); }
 104
 105     // return TRUE if we have anything to read, don't block
 106     virtual bool CanRead() const;
 107 };
 108
 109 #endif // wxUSE_STREAMS
 110
 111 #endif // _WX_UNIX_PIPE_H_
 112