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-rw-r--r--libc/stdio/stdio.c63
1 files changed, 52 insertions, 11 deletions
diff --git a/libc/stdio/stdio.c b/libc/stdio/stdio.c
index 7db727c76..4cd330a9b 100644
--- a/libc/stdio/stdio.c
+++ b/libc/stdio/stdio.c
@@ -50,6 +50,15 @@
* Added internal function _wstdio_fwrite.
* Jan 3, 2003
* Fixed a bug in _wstdio_fwrite.
+ *
+ * Jan 22, 2003
+ * Fixed a bug related file position in append mode. _stdio_fwrite now
+ * seeks to the end of the stream when append mode is set and we are
+ * transitioning to write mode, so that subsequent ftell() return
+ * values are correct.
+ * Also fix _stdio_fopen to support fdopen() with append specified when
+ * the underlying file didn't have O_APPEND set. It now sets the
+ * O_APPEND flag as recommended by SUSv3 and is done by glibc.
*/
/* Before we include anything, convert L_ctermid to L_ctermid_function
@@ -1507,8 +1516,8 @@ size_t _stdio_fread(unsigned char *buffer, size_t bytes, register FILE *stream)
* error flag before/after the write process, but it doesn't seem worth
* the trouble. */
-/* Like standard write, but always does a full write unless error plus
- *deals correctly with bufsize > SSIZE_MAX... not much on an issue on linux
+/* Like standard write, but always does a full write unless error, plus
+ * deals correctly with bufsize > SSIZE_MAX... not much on an issue on linux
* but definitly could be on Elks. Also on Elks, always loops for EINTR..
* Returns number of bytes written, so a short write indicates an error */
static size_t _stdio_WRITE(register FILE *stream,
@@ -1592,8 +1601,18 @@ size_t _stdio_fwrite(const unsigned char *buffer, size_t bytes,
stream->bufgetc =
#endif /* __STDIO_GETC_MACRO */
stream->bufpos = stream->bufread = stream->bufstart;
+ } else
+#endif
+ if ((stream->modeflags & (__FLAG_WRITING|__FLAG_APPEND)) == __FLAG_APPEND) {
+ /* Append mode, but not currently writing. Need to seek to end for proper
+ * ftell() return values. Don't worry if the stream isn't seekable. */
+ __offmax_t pos[1];
+ *pos = 0;
+ if (_stdio_lseek(stream, pos, SEEK_END) && (errno != EPIPE)) { /* Too big? */
+ stream->modeflags |= __FLAG_ERROR;
+ return 0;
+ }
}
-#endif
#ifdef __STDIO_PUTC_MACRO
/* We need to disable putc macro in case of error */
@@ -1716,6 +1735,19 @@ size_t _stdio_fwrite(const unsigned char *buffer, size_t bytes,
/* We always clear the reading flag in case at EOF. */
stream->modeflags &= ~(__FLAG_READING);
+
+ if ((stream->modeflags & (__FLAG_WRITING|__FLAG_APPEND)) == __FLAG_APPEND) {
+ /* Append mode, but not currently writing. Need to seek to end for proper
+ * ftell() return values. Don't worry if the stream isn't seekable. */
+ __offmax_t pos[1];
+ *pos = 0;
+ if (_stdio_lseek(stream, pos, SEEK_END) && (errno != EPIPE)) { /* Too big? */
+ stream->modeflags |= __FLAG_ERROR;
+ return 0;
+ }
+ }
+
+
/* Unlike the buffered case, we set the writing flag now since we don't
* need to do anything here for fflush(). */
stream->modeflags |= __FLAG_WRITING;
@@ -2322,17 +2354,26 @@ FILE *_stdio_fopen(const char * __restrict filename,
}
if (filedes >= 0) { /* Handle fdopen trickery. */
- /*
- * NOTE: it is insufficient to just check R/W/RW agreement.
- * We must also check for append mode agreement, as well as
- * largefile agreement if applicable.
- */
- int i = (open_mode & (O_ACCMODE|O_APPEND|O_LARGEFILE)) + 1;
-
- if ((i & (((int) filename) + 1)) != i) {
+ /* NOTE: it is insufficient to just check R/W/RW agreement.
+ * We must also check largefile compatibility if applicable.
+ * Also, if append mode is desired for fdopen but O_APPEND isn't
+ * currently set, then set it as recommended by SUSv3. However,
+ * if append mode is not specified for fdopen but O_APPEND is set,
+ * leave it set (glibc compat). */
+ int i = (open_mode & (O_ACCMODE|O_LARGEFILE)) + 1;
+
+ if (((i & (((int) filename) + 1)) != i) /* Check basic agreement. */
+ || (((open_mode & O_APPEND)
+ && !(((int) filename) & O_APPEND)
+ && fcntl(filedes, F_SETFL, O_APPEND))) /* Need O_APPEND. */
+ ) {
__set_errno(EINVAL);
filedes = -1;
}
+#ifdef __STDIO_LARGE_FILES
+ /* For later... to reflect largefile setting in stream flags. */
+ open_mode |= (((int) filename) & O_LARGEFILE);
+#endif /* __STDIO_LARGE_FILES */
stream->filedes = filedes;
} else {
#ifdef __STDIO_LARGE_FILES