1/*****************************************************************************/
2/* */
3/* fileio.c */
4/* */
5/* File I/O for the sp65 sprite and bitmap utility */
6/* */
7/* */
8/* */
9/* (C) 1998-2012, Ullrich von Bassewitz */
10/* Roemerstrasse 52 */
11/* D-70794 Filderstadt */
12/* EMail: uz@cc65.org */
13/* */
14/* */
15/* This software is provided 'as-is', without any expressed or implied */
16/* warranty. In no event will the authors be held liable for any damages */
17/* arising from the use of this software. */
18/* */
19/* Permission is granted to anyone to use this software for any purpose, */
20/* including commercial applications, and to alter it and redistribute it */
21/* freely, subject to the following restrictions: */
22/* */
23/* 1. The origin of this software must not be misrepresented; you must not */
24/* claim that you wrote the original software. If you use this software */
25/* in a product, an acknowledgment in the product documentation would be */
26/* appreciated but is not required. */
27/* 2. Altered source versions must be plainly marked as such, and must not */
28/* be misrepresented as being the original software. */
29/* 3. This notice may not be removed or altered from any source */
30/* distribution. */
31/* */
32/*****************************************************************************/
33
34
35
36#include <string.h>
37#include <errno.h>
38
39/* od65 */
40#include "error.h"
41#include "fileio.h"
42
43
44
45/*****************************************************************************/
46/* Code */
47/*****************************************************************************/
48
49
50
51void FileSetPos (FILE* F, unsigned long Pos)
52/* Seek to the given absolute position, fail on errors */
53{
54 if (fseek (F, Pos, SEEK_SET) != 0) {
55 Error ("Cannot seek: %s", strerror (errno));
56 }
57}
58
59
60
61unsigned long FileGetPos (FILE* F)
62/* Return the current file position, fail on errors */
63{
64 long Pos = ftell (F);
65 if (Pos < 0) {
66 Error ("Error in ftell: %s", strerror (errno));
67 }
68 return Pos;
69}
70
71
72
73unsigned Read8 (FILE* F)
74/* Read an 8 bit value from the file */
75{
76 int C = getc (F);
77 if (C == EOF) {
78 Error ("Read error (file corrupt?)");
79 }
80 return C;
81}
82
83
84
85unsigned Read16 (FILE* F)
86/* Read a 16 bit value from the file */
87{
88 unsigned Lo = Read8 (F);
89 unsigned Hi = Read8 (F);
90 return (Hi << 8) | Lo;
91}
92
93
94
95unsigned long Read24 (FILE* F)
96/* Read a 24 bit value from the file */
97{
98 unsigned long Lo = Read16 (F);
99 unsigned long Hi = Read8 (F);
100 return (Hi << 16) | Lo;
101}
102
103
104
105unsigned long Read32 (FILE* F)
106/* Read a 32 bit value from the file */
107{
108 unsigned long Lo = Read16 (F);
109 unsigned long Hi = Read16 (F);
110 return (Hi << 16) | Lo;
111}
112
113
114
115void* ReadData (FILE* F, void* Data, unsigned Size)
116/* Read data from the file */
117{
118 /* Accept zero sized reads */
119 if (Size > 0) {
120 if (fread (Data, 1, Size, F) != Size) {
121 Error ("Read error (file corrupt?)");
122 }
123 }
124 return Data;
125}
126