X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;ds=sidebyside;f=lib%2Fsafe-read.c;h=0cb1edee8bc789ab6589d2cd93c7e265ce1a418a;hb=a0092d82930eaf9bcbdf1840b2133e24997d2311;hp=f31ddc10418880c8b74e5b330b3d02c88b8d3779;hpb=32c761fed48a5b781c9177878a57a2d153caf680;p=gnulib.git
diff --git a/lib/safe-read.c b/lib/safe-read.c
index f31ddc104..0cb1edee8 100644
--- a/lib/safe-read.c
+++ b/lib/safe-read.c
@@ -1,10 +1,12 @@
-/* An interface to read that retries after interrupts.
- Copyright (C) 1993, 1994, 1998, 2002 Free Software Foundation, Inc.
+/* An interface to read and write that retries after interrupts.
- This program is free software; you can redistribute it and/or modify
+ Copyright (C) 1993, 1994, 1998, 2002, 2003, 2004, 2005, 2006 Free
+ Software Foundation, Inc.
+
+ This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
- the Free Software Foundation; either version 2, or (at your option)
- any later version.
+ the Free Software Foundation; either version 3 of the License, or
+ (at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ -12,26 +14,22 @@
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
- along with this program; if not, write to the Free Software Foundation,
- Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
+ along with this program. If not, see . */
-#if HAVE_CONFIG_H
-# include
-#endif
+#include
/* Specification. */
-#include "safe-read.h"
+#ifdef SAFE_WRITE
+# include "safe-write.h"
+#else
+# include "safe-read.h"
+#endif
/* Get ssize_t. */
#include
-#if HAVE_UNISTD_H
-# include
-#endif
+#include
#include
-#ifndef errno
-extern int errno;
-#endif
#ifdef EINTR
# define IS_EINTR(x) ((x) == EINTR)
@@ -41,43 +39,39 @@ extern int errno;
#include
-#ifndef CHAR_BIT
-# define CHAR_BIT 8
-#endif
-
-/* The extra casts work around common compiler bugs. */
-#define TYPE_SIGNED(t) (! ((t) 0 < (t) -1))
-/* The outer cast is needed to work around a bug in Cray C 5.0.3.0.
- It is necessary at least when t == time_t. */
-#define TYPE_MINIMUM(t) ((t) (TYPE_SIGNED (t) \
- ? ~ (t) 0 << (sizeof (t) * CHAR_BIT - 1) : (t) 0))
-#define TYPE_MAXIMUM(t) ((t) (~ (t) 0 - TYPE_MINIMUM (t)))
-
-#ifndef INT_MAX
-# define INT_MAX TYPE_MAXIMUM (int)
+#ifdef SAFE_WRITE
+# define safe_rw safe_write
+# define rw write
+#else
+# define safe_rw safe_read
+# define rw read
+# undef const
+# define const /* empty */
#endif
-/* Read up to COUNT bytes at BUF from descriptor FD, retrying if interrupted.
- Return the actual number of bytes read, zero for EOF, or SAFE_RW_ERROR
- upon error. */
+/* Read(write) up to COUNT bytes at BUF from(to) descriptor FD, retrying if
+ interrupted. Return the actual number of bytes read(written), zero for EOF,
+ or SAFE_READ_ERROR(SAFE_WRITE_ERROR) upon error. */
size_t
-safe_read (int fd, void *buf, size_t count)
+safe_rw (int fd, void const *buf, size_t count)
{
- ssize_t result;
-
- /* POSIX limits COUNT to SSIZE_MAX, but we limit it further, requiring
- that COUNT <= INT_MAX, to avoid triggering a bug in Tru64 5.1.
- When decreasing COUNT, keep the file pointer block-aligned.
- Note that in any case, read may succeed, yet read fewer than COUNT
- bytes, so the caller must be prepared to handle partial results. */
- if (count > INT_MAX)
- count = INT_MAX & ~8191;
+ /* Work around a bug in Tru64 5.1. Attempting to read more than
+ INT_MAX bytes fails with errno == EINVAL. See
+ .
+ When decreasing COUNT, keep it block-aligned. */
+ enum { BUGGY_READ_MAXIMUM = INT_MAX & ~8191 };
- do
+ for (;;)
{
- result = read (fd, buf, count);
+ ssize_t result = rw (fd, buf, count);
+
+ if (0 <= result)
+ return result;
+ else if (IS_EINTR (errno))
+ continue;
+ else if (errno == EINVAL && BUGGY_READ_MAXIMUM < count)
+ count = BUGGY_READ_MAXIMUM;
+ else
+ return result;
}
- while (result < 0 && IS_EINTR (errno));
-
- return (size_t) result;
}