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     };
  33
  34     enum
  35     {
  36         INVALID_FD = -1
  37     };
  38
  39     // default ctor doesn't do anything
  40     wxPipe() { m_fds[Read] = m_fds[Write] = INVALID_FD; }
  41
  42     // create the pipe, return TRUE if ok, FALSE on error
  43     bool Create()
  44     {
  45         if ( pipe(m_fds) == -1 )
  46         {
  47             wxLogSysError(_("Pipe creation failed"));
  48
  49             return FALSE;
  50         }
  51
  52         return TRUE;
  53     }
  54
  55     // return TRUE if we were created successfully
  56     bool IsOk() const { return m_fds[Read] != INVALID_FD; }
  57
  58     // return the descriptor for one of the pipe ends
  59     int operator[](Direction which) const { return m_fds[which]; }
  60
  61     // detach a descriptor, meaning that the pipe dtor won't close it, and
  62     // return it
  63     int Detach(Direction which)
  64     {
  65         int fd = m_fds[which];
  66         m_fds[which] = INVALID_FD;
  67
  68         return fd;
  69     }
  70
  71     // close the pipe descriptors
  72     void Close()
  73     {
  74         for ( size_t n = 0; n < WXSIZEOF(m_fds); n++ )
  75         {
  76             if ( m_fds[n] != INVALID_FD )
  77             {
  78                 close(m_fds[n]);
  79                 m_fds[n] = INVALID_FD;
  80             }
  81         }
  82     }
  83
  84     // dtor closes the pipe descriptors
  85     ~wxPipe() { Close(); }
  86
  87 private:
  88     int m_fds[2];
  89 };
  90
  91 #if wxUSE_STREAMS && wxUSE_FILE
  92
  93 #include "wx/wfstream.h"
  94
  95 // ----------------------------------------------------------------------------
  96 // wxPipeInputStream: stream for reading from a pipe
  97 // ----------------------------------------------------------------------------
  98
  99 class wxPipeInputStream : public wxFileInputStream
 100 {
 101 public:
 102     wxPipeInputStream(int fd) : wxFileInputStream(fd) { }
 103
 104     // return TRUE if the pipe is still opened
 105     bool IsOpened() const { return !Eof(); }
 106
 107     // return TRUE if we have anything to read, don't block
 108     virtual bool CanRead() const;
 109 };
 110
 111 #endif // wxUSE_STREAMS && wxUSE_FILE
 112
 113 #endif // _WX_UNIX_PIPE_H_
 114