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-rw-r--r--lib/libc/stdio/ftell.c139
1 files changed, 139 insertions, 0 deletions
diff --git a/lib/libc/stdio/ftell.c b/lib/libc/stdio/ftell.c
new file mode 100644
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--- /dev/null
+++ b/lib/libc/stdio/ftell.c
@@ -0,0 +1,139 @@
+/*-
+ * Copyright (c) 1990, 1993
+ * The Regents of the University of California. All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Chris Torek.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 4. Neither the name of the University nor the names of its contributors
+ * may be used to endorse or promote products derived from this software
+ * without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#if defined(LIBC_SCCS) && !defined(lint)
+static char sccsid[] = "@(#)ftell.c 8.2 (Berkeley) 5/4/95";
+#endif /* LIBC_SCCS and not lint */
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include "namespace.h"
+#include <sys/types.h>
+#include <errno.h>
+#include <limits.h>
+#include <stdio.h>
+#include "un-namespace.h"
+#include "local.h"
+#include "libc_private.h"
+
+/*
+ * standard ftell function.
+ */
+long
+ftell(fp)
+ FILE *fp;
+{
+ off_t rv;
+
+ rv = ftello(fp);
+ if (rv > LONG_MAX) {
+ errno = EOVERFLOW;
+ return (-1);
+ }
+ return (rv);
+}
+
+/*
+ * ftello: return current offset.
+ */
+off_t
+ftello(fp)
+ FILE *fp;
+{
+ fpos_t rv;
+ int ret;
+
+ FLOCKFILE(fp);
+ ret = _ftello(fp, &rv);
+ FUNLOCKFILE(fp);
+ if (ret)
+ return (-1);
+ if (rv < 0) { /* Unspecified value because of ungetc() at 0 */
+ errno = ESPIPE;
+ return (-1);
+ }
+ return (rv);
+}
+
+int
+_ftello(fp, offset)
+ FILE *fp;
+ fpos_t *offset;
+{
+ fpos_t pos;
+ size_t n;
+
+ if (fp->_seek == NULL) {
+ errno = ESPIPE; /* historic practice */
+ return (1);
+ }
+
+ /*
+ * Find offset of underlying I/O object, then
+ * adjust for buffered bytes.
+ */
+ if (fp->_flags & __SOFF)
+ pos = fp->_offset;
+ else {
+ pos = _sseek(fp, (fpos_t)0, SEEK_CUR);
+ if (pos == -1)
+ return (1);
+ }
+ if (fp->_flags & __SRD) {
+ /*
+ * Reading. Any unread characters (including
+ * those from ungetc) cause the position to be
+ * smaller than that in the underlying object.
+ */
+ if ((pos -= (HASUB(fp) ? fp->_ur : fp->_r)) < 0) {
+ fp->_flags |= __SERR;
+ errno = EIO;
+ return (1);
+ }
+ if (HASUB(fp))
+ pos -= fp->_r; /* Can be negative at this point. */
+ } else if ((fp->_flags & __SWR) && fp->_p != NULL) {
+ /*
+ * Writing. Any buffered characters cause the
+ * position to be greater than that in the
+ * underlying object.
+ */
+ n = fp->_p - fp->_bf._base;
+ if (pos > OFF_MAX - n) {
+ errno = EOVERFLOW;
+ return (1);
+ }
+ pos += n;
+ }
+ *offset = pos;
+ return (0);
+}
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