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Re: [PATCH v2][BZ #13152] fmemopen does not honor append mode.
- From: OndÅej BÃlka <neleai at seznam dot cz>
- To: Roland McGrath <roland at hack dot frob dot com>
- Cc: "Joseph S. Myers" <joseph at codesourcery dot com>, libc-alpha at sourceware dot org
- Date: Mon, 20 May 2013 13:31:24 +0200
- Subject: Re: [PATCH v2][BZ #13152] fmemopen does not honor append mode.
- References: <20130509164726 dot GA32347 at domone dot kolej dot mff dot cuni dot cz> <Pine dot LNX dot 4 dot 64 dot 1305091653510 dot 25142 at digraph dot polyomino dot org dot uk> <20130514131101 dot GA3860 at domone dot kolej dot mff dot cuni dot cz> <20130517002937 dot 430692C084 at topped-with-meat dot com> <20130520084328 dot GC32195 at domone dot kolej dot mff dot cuni dot cz>
On Mon, May 20, 2013 at 10:43:29AM +0200, OndÅej BÃlka wrote:
> On Thu, May 16, 2013 at 05:29:37PM -0700, Roland McGrath wrote:
> > How can this possibly be right for "a+" mode or ftell?
> >
> ok, need will post new version.
New version. I added append flag and refactored fmemopen a bit.
---
libio/fmemopen.c | 74 ++++++++++++++++++----------------------
libio/test-fmemopen-bz13152.c | 44 ++++++++++++++++++++++++
2 files changed, 77 insertions(+), 41 deletions(-)
create mode 100644 libio/test-fmemopen-bz13152.c
diff --git a/libio/fmemopen.c b/libio/fmemopen.c
index 02c764f..d0d2f14 100644
--- a/libio/fmemopen.c
+++ b/libio/fmemopen.c
@@ -82,6 +82,7 @@ struct fmemopen_cookie_struct
char *buffer;
int mybuffer;
int binmode;
+ int append;
size_t size;
_IO_off64_t pos;
size_t maxpos;
@@ -91,9 +92,7 @@ struct fmemopen_cookie_struct
static ssize_t
fmemopen_read (void *cookie, char *b, size_t s)
{
- fmemopen_cookie_t *c;
-
- c = (fmemopen_cookie_t *) cookie;
+ fmemopen_cookie_t *c = (fmemopen_cookie_t *) cookie;
if (c->pos + s > c->size)
{
@@ -115,29 +114,28 @@ fmemopen_read (void *cookie, char *b, size_t s)
static ssize_t
fmemopen_write (void *cookie, const char *b, size_t s)
{
- fmemopen_cookie_t *c;
int addnullc;
+ fmemopen_cookie_t *c = (fmemopen_cookie_t *) cookie;
- c = (fmemopen_cookie_t *) cookie;
-
+ _IO_off64_t pos = c->append ? c->maxpos : c->pos;
addnullc = c->binmode == 0 && (s == 0 || b[s - 1] != '\0');
- if (c->pos + s + addnullc > c->size)
+ if (pos + s + addnullc > c->size)
{
- if ((size_t) (c->pos + addnullc) == c->size)
+ if ((size_t) (pos + addnullc) == c->size)
{
__set_errno (ENOSPC);
return 0;
}
- s = c->size - c->pos - addnullc;
+ s = c->size - pos - addnullc;
}
- memcpy (&(c->buffer[c->pos]), b, s);
+ memcpy (&(c->buffer[pos]), b, s);
- c->pos += s;
- if ((size_t) c->pos > c->maxpos)
+ pos += s;
+ if ((size_t) pos > c->maxpos)
{
- c->maxpos = c->pos;
+ c->maxpos = pos;
if (addnullc)
c->buffer[c->maxpos] = '\0';
}
@@ -150,9 +148,7 @@ static int
fmemopen_seek (void *cookie, _IO_off64_t *p, int w)
{
_IO_off64_t np;
- fmemopen_cookie_t *c;
-
- c = (fmemopen_cookie_t *) cookie;
+ fmemopen_cookie_t *c = (fmemopen_cookie_t *) cookie;
switch (w)
{
@@ -184,9 +180,7 @@ fmemopen_seek (void *cookie, _IO_off64_t *p, int w)
static int
fmemopen_close (void *cookie)
{
- fmemopen_cookie_t *c;
-
- c = (fmemopen_cookie_t *) cookie;
+ fmemopen_cookie_t *c = (fmemopen_cookie_t *) cookie;
if (c->mybuffer)
free (c->buffer);
@@ -204,7 +198,6 @@ fmemopen (void *buf, size_t len, const char *mode)
if (__builtin_expect (len == 0, 0))
{
- einval:
__set_errno (EINVAL);
return NULL;
}
@@ -217,39 +210,38 @@ fmemopen (void *buf, size_t len, const char *mode)
if (c->mybuffer)
{
- c->buffer = (char *) malloc (len);
- if (c->buffer == NULL)
+ buf = (char *) malloc (len);
+ if (buf == NULL)
{
free (c);
return NULL;
}
- c->buffer[0] = '\0';
- c->maxpos = 0;
+ buf[0] = '\0';
}
- else
+
+ if (__builtin_expect ((uintptr_t) len > -(uintptr_t) buf, 0))
{
- if (__builtin_expect ((uintptr_t) len > -(uintptr_t) buf, 0))
- {
- free (c);
- goto einval;
- }
-
- c->buffer = buf;
-
- if (mode[0] == 'w')
- c->buffer[0] = '\0';
-
- c->maxpos = strnlen (c->buffer, len);
+ free (c);
+ __set_errno (EINVAL);
+ return NULL;
}
+ if (mode[0] == 'w')
+ buf[0] = '\0';
+
+ c->buffer = buf;
+ c->maxpos = strnlen (c->buffer, len);
c->size = len;
+ c->pos = 0;
+ c->append = mode[0] == 'a';
+ c->binmode = 0;
- if (mode[0] == 'a')
+ if (mode[0] == 'a' && mode[1] != '+')
c->pos = c->maxpos;
- else
- c->pos = 0;
- c->binmode = mode[0] != '\0' && mode[1] == 'b';
+ for (int i = 0; mode[i]; i++)
+ if (mode[i] == 'b')
+ c->binmode = 1;
iof.read = fmemopen_read;
iof.write = fmemopen_write;
diff --git a/libio/test-fmemopen-bz13152.c b/libio/test-fmemopen-bz13152.c
new file mode 100644
index 0000000..f2fc5bc
--- /dev/null
+++ b/libio/test-fmemopen-bz13152.c
@@ -0,0 +1,44 @@
+/* Test for binary mode see bug 13152.
+ Copyright (C) 2013 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <http://www.gnu.org/licenses/>. */
+
+#include <stdio.h>
+#include <string.h>
+
+int
+do_test (int argc, char **argv)
+{
+ char buf[20] = "hello, world";
+ char expected[20] = "hello, worldX";
+ FILE *fp = fmemopen(buf, 20, "a+");
+ fseek(fp, 0, SEEK_SET);
+
+ fflush(fp);
+ fprintf(fp, "X");
+ fclose(fp);
+
+ for (int i = 0; i < strlen (expected); i++)
+ if (buf[i] != expected[i])
+ {
+ printf ("Disagree at position %i\n", i);
+ return 1;
+ }
+
+ return 0;
+}
+
+#include "../test-skeleton.c"
--
1.7.4.4