diff options
| -rw-r--r-- | libc/stdio/stdio.c | 63 |
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 |