tools/power/acpi/common/cmfsize.c

   1 // SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
   2 /******************************************************************************
   3  *
   4  * Module Name: cfsize - Common get file size function
   5  *
   6  * Copyright (C) 2000 - 2020, Intel Corp.
   7  *
   8  *****************************************************************************/
   9
  10 #include <acpi/acpi.h>
  11 #include "accommon.h"
  12 #include "acapps.h"
  13
  14 #define _COMPONENT          ACPI_TOOLS
  15 ACPI_MODULE_NAME("cmfsize")
  16
  17 /*******************************************************************************
  18  *
  19  * FUNCTION:    cm_get_file_size
  20  *
  21  * PARAMETERS:  file                    - Open file descriptor
  22  *
  23  * RETURN:      File Size. On error, -1 (ACPI_UINT32_MAX)
  24  *
  25  * DESCRIPTION: Get the size of a file. Uses seek-to-EOF. File must be open.
  26  *              Does not disturb the current file pointer.
  27  *
  28  ******************************************************************************/
  29 u32 cm_get_file_size(ACPI_FILE file)
  30 {
  31         long file_size;
  32         long current_offset;
  33         acpi_status status;
  34
  35         /* Save the current file pointer, seek to EOF to obtain file size */
  36
  37         current_offset = ftell(file);
  38         if (current_offset < 0) {
  39                 goto offset_error;
  40         }
  41
  42         status = fseek(file, 0, SEEK_END);
  43         if (ACPI_FAILURE(status)) {
  44                 goto seek_error;
  45         }
  46
  47         file_size = ftell(file);
  48         if (file_size < 0) {
  49                 goto offset_error;
  50         }
  51
  52         /* Restore original file pointer */
  53
  54         status = fseek(file, current_offset, SEEK_SET);
  55         if (ACPI_FAILURE(status)) {
  56                 goto seek_error;
  57         }
  58
  59         return ((u32)file_size);
  60
  61 offset_error:
  62         fprintf(stderr, "Could not get file offset\n");
  63         return (ACPI_UINT32_MAX);
  64
  65 seek_error:
  66         fprintf(stderr, "Could not set file offset\n");
  67         return (ACPI_UINT32_MAX);
  68 }