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#include "stdio_impl.h"
#include <errno.h>
int __fseeko_unlocked(FILE *f, off_t off, int whence)
{
/* Fail immediately for invalid whence argument. */
if (whence != SEEK_CUR && whence != SEEK_SET && whence != SEEK_END) {
errno = EINVAL;
return -1;
}
/* Adjust relative offset for unread data in buffer, if any. */
if (whence == SEEK_CUR && f->rend) off -= f->rend - f->rpos;
/* Flush write buffer, and report error on failure. */
if (f->wpos != f->wbase) {
f->write(f, 0, 0);
if (!f->wpos) return -1;
}
/* Leave writing mode */
f->wpos = f->wbase = f->wend = 0;
/* Perform the underlying seek. */
if (f->seek(f, off, whence) < 0) return -1;
/* If seek succeeded, file is seekable and we discard read buffer. */
f->rpos = f->rend = 0;
f->flags &= ~F_EOF;
return 0;
}
int __fseeko(FILE *f, off_t off, int whence)
{
int result;
FLOCK(f);
result = __fseeko_unlocked(f, off, whence);
FUNLOCK(f);
return result;
}
int fseek(FILE *f, long off, int whence)
{
return __fseeko(f, off, whence);
}
weak_alias(__fseeko, fseeko);
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