Added configure check for pread/pwrite.
diff --git a/library/port.c b/library/port.c
index 132cbed..7763081 100644
--- a/library/port.c
+++ b/library/port.c
@@ -379,6 +379,59 @@
}
#endif /* HAVE_LSTAT */
+
+/***********************************************************************
+ * pread
+ *
+ * FIXME: this is not thread-safe
+ */
+#ifndef HAVE_PREAD
+ssize_t pread( int fd, void *buf, size_t count, off_t offset )
+{
+ ssize_t ret;
+ off_t old_pos;
+
+ if ((old_pos = lseek( fd, 0, SEEK_CUR )) == -1) return -1;
+ if (lseek( fd, offset, SEEK_SET ) == -1) return -1;
+ if ((ret = read( fd, buf, count )) == -1)
+ {
+ int err = errno; /* save errno */
+ lseek( fd, old_pos, SEEK_SET );
+ errno = err;
+ return -1;
+ }
+ if (lseek( fd, old_pos, SEEK_SET ) == -1) return -1;
+ return ret;
+}
+#endif /* HAVE_PREAD */
+
+
+/***********************************************************************
+ * pwrite
+ *
+ * FIXME: this is not thread-safe
+ */
+#ifndef HAVE_PWRITE
+ssize_t pwrite( int fd, const void *buf, size_t count, off_t offset )
+{
+ ssize_t ret;
+ off_t old_pos;
+
+ if ((old_pos = lseek( fd, 0, SEEK_CUR )) == -1) return -1;
+ if (lseek( fd, offset, SEEK_SET ) == -1) return -1;
+ if ((ret = write( fd, buf, count )) == -1)
+ {
+ int err = errno; /* save errno */
+ lseek( fd, old_pos, SEEK_SET );
+ errno = err;
+ return -1;
+ }
+ if (lseek( fd, old_pos, SEEK_SET ) == -1) return -1;
+ return ret;
+}
+#endif /* HAVE_PWRITE */
+
+
/***********************************************************************
* getrlimit
*/
