From: Christos Zoulas <christos@zoulas.com>
Date: Mon, 15 Sep 2014 19:11:25 +0000 (+0000)
Subject: we are not supposed to modify the file pointer.
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=1580848d606059629f9dcdace14ccd6fed9c7c14;p=file

we are not supposed to modify the file pointer.
---

diff --git a/src/pread.c b/src/pread.c
index 649f6095..72d3a6b3 100644
--- a/src/pread.c
+++ b/src/pread.c
@@ -1,14 +1,23 @@
 #include "file.h"
 #ifndef lint
-FILE_RCSID("@(#)$File: pread.c,v 1.2 2013/04/02 16:23:07 christos Exp $")
+FILE_RCSID("@(#)$File: pread.c,v 1.3 2014/09/15 19:11:25 christos Exp $")
 #endif  /* lint */
 #include <fcntl.h>
 #include <unistd.h>
 
 ssize_t
 pread(int fd, void *buf, size_t len, off_t off) {
-	if (lseek(fd, off, SEEK_SET) == (off_t)-1)
+	off_t old;
+	ssize_t rv;
+
+	if ((old = lseek(fd, off, SEEK_SET)) == -1)
+		return -1;
+
+	if ((rv = read(fd, buf, len)) == -1)
+		return -1;
+
+	if (lseek(fd, old, SEEK_SET) == -1)
 		return -1;
 
-	return read(fd, buf, len);
+	return rv;
 }