mirror of https://github.com/cc65/cc65.git
59 lines
1.2 KiB
C
59 lines
1.2 KiB
C
/*
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** 2012-06-03, Ullrich von Bassewitz. Based on code by Groepaz.
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** 2014-07-16, Greg King
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*/
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#include <fcntl.h>
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#include <unistd.h>
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#include <errno.h>
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#include "dir.h"
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void __fastcall__ seekdir (register DIR* dir, long offs)
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{
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unsigned o;
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unsigned char count;
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unsigned char buf[128];
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/* Make sure that we have a reasonable value for offs. We reject
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** negative numbers by converting them to (very high) unsigned values.
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*/
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if ((unsigned long)offs > 0x1000uL) {
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errno = EINVAL;
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return;
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}
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/* Close the directory file descriptor */
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close (dir->fd);
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/* Reopen it using the old name */
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dir->fd = open (dir->name, O_RDONLY);
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if (dir->fd < 0) {
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/* Oops! */
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return;
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}
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/* Skip until we've reached the target offset in the directory */
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o = dir->off = (unsigned)offs;
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while (o) {
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/* Determine size of next chunk to read */
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if (o > sizeof (buf)) {
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count = sizeof (buf);
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o -= sizeof (buf);
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} else {
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count = (unsigned char)o;
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o = 0;
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}
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/* Skip */
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if (!_dirread (dir, buf, count)) {
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return;
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}
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}
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}
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