forked from backup/30dayMakeOS
75 lines
1.4 KiB
C
75 lines
1.4 KiB
C
/* 文件相关函数 */
|
|
|
|
#include "bootpack.h"
|
|
|
|
void file_readfat(int *fat, unsigned char *img)
|
|
/*将磁盘映像中的FAT解压缩 */
|
|
{
|
|
int i, j = 0;
|
|
for (i = 0; i < 2880; i += 2) {
|
|
fat[i + 0] = (img[j + 0] | img[j + 1] << 8) & 0xfff;
|
|
fat[i + 1] = (img[j + 1] >> 4 | img[j + 2] << 4) & 0xfff;
|
|
j += 3;
|
|
}
|
|
return;
|
|
}
|
|
|
|
void file_loadfile(int clustno, int size, char *buf, int *fat, char *img)
|
|
{
|
|
int i;
|
|
for (;;) {
|
|
if (size <= 512) {
|
|
for (i = 0; i < size; i++) {
|
|
buf[i] = img[clustno * 512 + i];
|
|
}
|
|
break;
|
|
}
|
|
for (i = 0; i < 512; i++) {
|
|
buf[i] = img[clustno * 512 + i];
|
|
}
|
|
size -= 512;
|
|
buf += 512;
|
|
clustno = fat[clustno];
|
|
}
|
|
return;
|
|
}
|
|
|
|
struct FILEINFO *file_search(char *name, struct FILEINFO *finfo, int max)
|
|
{
|
|
int i, j;
|
|
char s[12];
|
|
for (j = 0; j < 11; j++) {
|
|
s[j] = ' ';
|
|
}
|
|
j = 0;
|
|
for (i = 0; name[i] != 0; i++) {
|
|
if (j >= 11) { return 0; /*没有找到*/ }
|
|
if (name[i] == '.' && j <= 8) {
|
|
j = 8;
|
|
} else {
|
|
s[j] = name[i];
|
|
if ('a' <= s[j] && s[j] <= 'z') {
|
|
/*将小写字母转换为大写字母*/
|
|
s[j] -= 0x20;
|
|
}
|
|
j++;
|
|
}
|
|
}
|
|
for (i = 0; i < max; ) {
|
|
if (finfo->name[0] == 0x00) {
|
|
break;
|
|
}
|
|
if ((finfo[i].type & 0x18) == 0) {
|
|
for (j = 0; j < 11; j++) {
|
|
if (finfo[i].name[j] != s[j]) {
|
|
goto next;
|
|
}
|
|
}
|
|
return finfo + i; /*找到文件*/
|
|
}
|
|
next:
|
|
i++;
|
|
}
|
|
return 0; /*没有找到*/
|
|
}
|