com32/lib/sys/stdcon_read.c

   1 /* ----------------------------------------------------------------------- *
   2  *
   3  *   Copyright 2004 H. Peter Anvin - All Rights Reserved
   4  *
   5  *   Permission is hereby granted, free of charge, to any person
   6  *   obtaining a copy of this software and associated documentation
   7  *   files (the "Software"), to deal in the Software without
   8  *   restriction, including without limitation the rights to use,
   9  *   copy, modify, merge, publish, distribute, sublicense, and/or
  10  *   sell copies of the Software, and to permit persons to whom
  11  *   the Software is furnished to do so, subject to the following
  12  *   conditions:
  13  *
  14  *   The above copyright notice and this permission notice shall
  15  *   be included in all copies or substantial portions of the Software.
  16  *
  17  *   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  18  *   EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
  19  *   OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  20  *   NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
  21  *   HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
  22  *   WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  23  *   FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  24  *   OTHER DEALINGS IN THE SOFTWARE.
  25  *
  26  * ----------------------------------------------------------------------- */
  27
  28 /*
  29  * stdcon_read.c
  30  *
  31  * Line-oriented reading from the standard console
  32  */
  33
  34 #include <errno.h>
  35 #include <string.h>
  36 #include <com32.h>
  37 #include <minmax.h>
  38 #include "file.h"
  39
  40 extern ssize_t __rawcon_read(struct file_info *fp, void *buf, size_t count);
  41
  42 static ssize_t __stdcon_read(struct file_info *fp, void *buf, size_t count)
  43 {
  44   char *bufp = buf;
  45   size_t n = 0;
  46   char ch;
  47
  48   (void)fp;
  49
  50   while ( n < count ) {
  51     if ( fp->i.nbytes ) {
  52       ch = *bufp++ = *fp->i.datap++;
  53       fp->i.nbytes--;
  54       n++;
  55       if ( ch == '\n' )
  56         return n;
  57     } else {
  58       fp->i.nbytes = __line_input(fp, fp->i.buf, MAXBLOCK,
  59                                     __rawcon_read);
  60       fp->i.datap = fp->i.buf;
  61
  62       if ( fp->i.nbytes == 0 )
  63         return n;
  64     }
  65   }
  66
  67   return n;
  68 }
  69
  70 const struct input_dev dev_stdcon_r = {
  71   .dev_magic  = __DEV_MAGIC,
  72   .flags      = __DEV_TTY | __DEV_INPUT,
  73   .fileflags  = O_RDONLY,
  74   .read       = __stdcon_read,
  75   .close      = NULL,
  76   .open       = NULL,
  77 };