/*
* fseek.c
*
- * Christian Groessler, 07-Aug-2000
+ * Christian Groessler, 2000-08-07
+ * Ullrich von Bassewitz, 2004-05-12
*/
+
#include <stdio.h>
#include <errno.h>
-#include <fcntl.h>
+#include <unistd.h>
#include "_file.h"
-int fseek(FILE* f, long offset, int whence)
+
+/*****************************************************************************/
+/* Code */
+/*****************************************************************************/
+
+
+
+int __fastcall__ fseek (register FILE* f, long offset, int whence)
{
long res;
/* Is the file open? */
if ((f->f_flags & _FOPEN) == 0) {
- _errno = EINVAL; /* File not open */
- return 1;
+ _seterrno (EINVAL); /* File not open */
+ return -1;
}
+ /* If we have a pushed back character, and whence is relative to the
+ * current position, correct the offset.
+ */
+ if ((f->f_flags & _FPUSHBACK) && whence == SEEK_CUR) {
+ --offset;
+ }
+
+ /* Do the seek */
res = lseek(f->f_fd, offset, whence);
- if (res == -1L) return 1;
- return 0;
+
+ /* If the seek was successful. Discard any effects of the ungetc function,
+ * and clear the end-of-file indicator. Otherwise set the error indicator
+ * on the stream, and return -1. We will check for >= 0 here, because that
+ * saves some code, and we don't have files with 2 gigabytes in size
+ * anyway:-)
+ */
+ if (res >= 0) {
+ f->f_flags &= ~(_FEOF | _FPUSHBACK);
+ return 0;
+ } else {
+ f->f_flags |= _FERROR;
+ return -1;
+ }
}