1 /***************************************************************************
2 * Copyright (c) 2024 Microsoft Corporation
3 *
4 * This program and the accompanying materials are made available under the
5 * terms of the MIT License which is available at
6 * https://opensource.org/licenses/MIT.
7 *
8 * SPDX-License-Identifier: MIT
9 **************************************************************************/
10
11
12 /**************************************************************************/
13 /**************************************************************************/
14 /** */
15 /** FileX Component */
16 /** */
17 /** File */
18 /** */
19 /**************************************************************************/
20 /**************************************************************************/
21
22 #define FX_SOURCE_CODE
23
24
25 /* Include necessary system files. */
26
27 #include "fx_api.h"
28 #include "fx_file.h"
29
30 FX_CALLER_CHECKING_EXTERNS
31
32
33 /**************************************************************************/
34 /* */
35 /* FUNCTION RELEASE */
36 /* */
37 /* _fxe_file_relative_seek PORTABLE C */
38 /* 6.1 */
39 /* AUTHOR */
40 /* */
41 /* William E. Lamie, Microsoft Corporation */
42 /* */
43 /* DESCRIPTION */
44 /* */
45 /* This function checks for errors in the file relative seek call. */
46 /* */
47 /* INPUT */
48 /* */
49 /* file_ptr File control block pointer */
50 /* byte_offset Byte offset of the seek */
51 /* seek_from Direction for relative seek, */
52 /* legal values are: */
53 /* */
54 /* FX_SEEK_BEGIN */
55 /* FX_SEEK_END */
56 /* FX_SEEK_FORWARD */
57 /* FX_SEEK_BACK */
58 /* */
59 /* OUTPUT */
60 /* */
61 /* return status */
62 /* */
63 /* CALLS */
64 /* */
65 /* _fx_file_relative_seek Actual relative file seek */
66 /* service */
67 /* */
68 /* CALLED BY */
69 /* */
70 /* Application Code */
71 /* */
72 /* RELEASE HISTORY */
73 /* */
74 /* DATE NAME DESCRIPTION */
75 /* */
76 /* 05-19-2020 William E. Lamie Initial Version 6.0 */
77 /* 09-30-2020 William E. Lamie Modified comment(s), */
78 /* resulting in version 6.1 */
79 /* */
80 /**************************************************************************/
_fxe_file_relative_seek(FX_FILE * file_ptr,ULONG byte_offset,UINT seek_from)81 UINT _fxe_file_relative_seek(FX_FILE *file_ptr, ULONG byte_offset, UINT seek_from)
82 {
83
84 UINT status;
85
86
87 /* Check for a null file pointer. */
88 if (file_ptr == FX_NULL)
89 {
90 return(FX_PTR_ERROR);
91 }
92
93 /* Check for valid seek from option. */
94 if ((seek_from != FX_SEEK_BEGIN) && (seek_from != FX_SEEK_END) &&
95 (seek_from != FX_SEEK_FORWARD) && (seek_from != FX_SEEK_BACK))
96 {
97 return(FX_INVALID_OPTION);
98 }
99
100 /* Check for a valid caller. */
101 FX_CALLER_CHECKING_CODE
102
103 /* Call actual file relative seek service. */
104 status = _fx_file_relative_seek(file_ptr, byte_offset, seek_from);
105
106 /* Seek is complete, return status. */
107 return(status);
108 }
109
110
