Line data    Source code

       1             : /*!
       2             :  * \file
       3             :  * \author Christopher Stender
       4             :  * \date 2018-02-15
       5             :  * \version 0.1
       6             :  *
       7             :  * \brief Read or write a fixed number of bytes
       8             :  *
       9             :  * \details
      10             :  * Use read_n() to read or write_n() to write a fixed number of bytes from or
      11             :  * to a file descriptor.
      12             :  *
      13             :  *\copyright
      14             :  * Copyright (c) 2023 Fraunhofer IIS
      15             :  *
      16             :  * Permission is hereby granted, free of charge, to any person obtaining a copy
      17             :  * of this software and associated documentation files (the “Software”), to deal
      18             :  * in the Software without restriction, including without limitation the rights
      19             :  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
      20             :  * copies of the Software, and to permit persons to whom the Software is
      21             :  * furnished to do so, subject to the following conditions:
      22             :  *
      23             :  * The above copyright notice and this permission notice shall be included in
      24             :  * all copies or substantial portions of the Software.
      25             :  *
      26             :  * THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
      27             :  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
      28             :  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
      29             :  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
      30             :  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
      31             :  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
      32             :  * THE SOFTWARE.
      33             :  */
      34             : 
      35             : #include <unistd.h>
      36             : 
      37             : #include "rw_n.h"
      38             : 
      39           0 : int read_n(int fd, void* buf, size_t count)
      40             : {
      41             :         int bytes_read;
      42           0 :         int to_read = count;
      43           0 :         uint8_t* buffer = (uint8_t*)buf;
      44             : 
      45           0 :         while(to_read > 0) {
      46           0 :                 bytes_read = read(fd, buffer, to_read);
      47           0 :                 if(bytes_read <= 0)
      48           0 :                         return bytes_read;
      49             : 
      50           0 :                 buffer += bytes_read;
      51           0 :                 to_read -= bytes_read;
      52             :         }
      53             : 
      54           0 :         return count;
      55             : }
      56             : 
      57           0 : int write_n(int fd, const void* buf, size_t count)
      58             : {
      59             :         int bytes_written;
      60           0 :         int to_send = count;
      61           0 :         uint8_t* buffer = (uint8_t*)buf;
      62             : 
      63           0 :         while(to_send > 0) {
      64           0 :                 bytes_written = write(fd, buffer, to_send);
      65           0 :                 if(bytes_written <= 0)
      66           0 :                         return bytes_written;
      67             : 
      68           0 :                 buffer += bytes_written;
      69           0 :                 to_send -= bytes_written;
      70             :         }
      71             : 
      72           0 :         return count;
      73             : }