StdLib/LibC/Uefi/InteractiveIO/NonCanonRead.c

   1 /** @file
   2   NonCanonical Interactive Input Function.
   3
   4   The functions assume that isatty() is TRUE at the time they are called.
   5   If _S_IWTTY is set, the device returns WIDE characters.
   6
   7   Copyright (c) 2012 - 2014, Intel Corporation. All rights reserved.<BR>
   8   This program and the accompanying materials are licensed and made available
   9   under the terms and conditions of the BSD License which accompanies this
  10   distribution.  The full text of the license may be found at
  11   http://opensource.org/licenses/bsd-license.php.
  12
  13   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  14   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  15 **/
  16 #include  <LibConfig.h>
  17
  18 #include  <sys/syslimits.h>
  19 #include  <sys/termios.h>
  20 #include  <Containers/Fifo.h>
  21 #include  <Device/IIO.h>
  22
  23 /** Perform a noncanonical read of input.
  24
  25     @param[in]    filp        Pointer to a file descriptor structure.
  26     @param[in]    BufferSize  Maximum number of bytes to return.
  27
  28     @retval    -1   An error has occurred.  Reason in errno.
  29     @retval    -1   No data returned.  None was ready.
  30     @retval    >0   The number of elements returned
  31 **/
  32 ssize_t
  33 IIO_NonCanonRead (
  34   struct __filedes *filp
  35   )
  36 {
  37   cIIO           *This;
  38   cFIFO          *InBuf;
  39   struct termios *Termio;
  40   ssize_t         NumRead;
  41   cc_t            tioMin;
  42   cc_t            tioTime;
  43   UINT32          InputType;
  44   wchar_t         InChar;     // Intermediate character buffer
  45
  46   NumRead = -1;
  47   InChar  = 0;      // Initialize so compilers don't complain.
  48   This    = filp->devdata;
  49   Termio  = &This->Termio;
  50   InBuf   = This->InBuf;
  51   tioMin  = Termio->c_cc[VMIN];
  52   tioTime = Termio->c_cc[VTIME];
  53
  54   if(tioMin >= MAX_INPUT) {
  55     tioMin = MAX_INPUT;
  56   }
  57   /*  There are four types of processing that may be done, based on
  58       the values of tioMin and tioTime.
  59           Min   Time    Type
  60           ---   ----    ----
  61            0      0       0   Return buffer contents or 1 new char
  62            0     >0       1   Return 0 or 1 character depending on timeout
  63           >0      0       2   Buffer Min chars. Return BufferSize chars.
  64           >0     >0       3   Return up to Min chars. Unless the inter-byte timer expires.
  65
  66     Currently, only type 0 is implemented.
  67   */
  68   InputType = 0;
  69   if(tioMin   != 0)     InputType = 2;
  70   if(tioTime  != 0)   ++InputType;
  71   //switch(InputType) {
  72   //  case 0:
  73       if(InBuf->IsEmpty(InBuf)) {
  74         NumRead = filp->f_ops->fo_read(filp, &filp->f_offset, sizeof(wchar_t), &InChar);
  75         if(NumRead > 0) {
  76           (void) InBuf->Write(InBuf, &InChar, 1);  // Buffer the character
  77         }
  78       }
  79   //    break;
  80   //  case 1:
  81   //    break;
  82   //  case 2:
  83   //    break;
  84   //  case 3:
  85   //    break;
  86   //}
  87   return NumRead;
  88 }