diff options
Diffstat (limited to 'libio/iofdopen.c')
| -rw-r--r-- | libio/iofdopen.c | 124 |
1 files changed, 124 insertions, 0 deletions
diff --git a/libio/iofdopen.c b/libio/iofdopen.c new file mode 100644 index 0000000000..6bb19fa214 --- /dev/null +++ b/libio/iofdopen.c @@ -0,0 +1,124 @@ +/* +Copyright (C) 1993, 1994 Free Software Foundation + +This file is part of the GNU IO Library. This library 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. + +This 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 General Public License for more details. + +You should have received a copy of the GNU General Public License +along with this library; see the file COPYING. If not, write to the Free +Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. + +As a special exception, if you link this library with files +compiled with a GNU compiler to produce an executable, this does not cause +the resulting executable to be covered by the GNU General Public License. +This exception does not however invalidate any other reasons why +the executable file might be covered by the GNU General Public License. */ + +#ifdef __STDC__ +#include <stdlib.h> +#endif +#include "libioP.h" +#include <fcntl.h> + +#ifndef _IO_fcntl +#define _IO_fcntl fcntl +#endif + +_IO_FILE * +_IO_fdopen (fd, mode) + int fd; + const char *mode; +{ + int read_write; + int posix_mode = 0; + struct _IO_FILE_plus *fp; + int fd_flags; + + switch (*mode++) + { + case 'r': + read_write = _IO_NO_WRITES; + break; + case 'w': + read_write = _IO_NO_READS; + break; + case 'a': + posix_mode = O_APPEND; + read_write = _IO_NO_READS|_IO_IS_APPENDING; + break; + default: +#ifdef EINVAL + errno = EINVAL; +#endif + return NULL; + } + if (mode[0] == '+' || (mode[0] == 'b' && mode[1] == '+')) + read_write &= _IO_IS_APPENDING; +#ifdef F_GETFL + fd_flags = _IO_fcntl (fd, F_GETFL); +#ifndef O_ACCMODE +#define O_ACCMODE (O_RDONLY|O_WRONLY|O_RDWR) +#endif + if (fd_flags == -1 + || ((fd_flags & O_ACCMODE) == O_RDONLY && !(read_write & _IO_NO_WRITES)) + || ((fd_flags & O_ACCMODE) == O_WRONLY && !(read_write & _IO_NO_READS))) + return NULL; + + /* The May 93 draft of P1003.4/D14.1 (redesignated as 1003.1b) + [System Application Program Interface (API) Amendment 1: + Realtime Extensions], Rationale B.8.3.3 + Open a Stream on a File Descriptor says: + + Although not explicitly required by POSIX.1, a good + implementation of append ("a") mode would cause the + O_APPEND flag to be set. + + (Historical implementations [such as Solaris2] do a one-time + seek in fdopen.) + + However, we do not turn O_APPEND off if the mode is "w" (even + though that would seem consistent) because that would be more + likely to break historical programs. + */ + if ((posix_mode & O_APPEND) && !(fd_flags & O_APPEND)) + { +#ifdef F_SETFL + if (_IO_fcntl (fd, F_SETFL, fd_flags | O_APPEND) == -1) +#endif + return NULL; + } +#endif + + fp = (struct _IO_FILE_plus *) malloc (sizeof (struct _IO_FILE_plus)); + if (fp == NULL) + return NULL; + _IO_init (&fp->file, 0); + _IO_JUMPS (&fp->file) = &_IO_file_jumps; + _IO_file_init (&fp->file); +#if !_IO_UNIFIED_JUMPTABLES + fp->vtable = NULL; +#endif + if (_IO_file_attach (&fp->file, fd) == NULL) + { + _IO_un_link (&fp->file); + free (fp); + return NULL; + } + fp->file._flags &= ~_IO_DELETE_DONT_CLOSE; + + fp->file._IO_file_flags = + _IO_mask_flags (&fp->file, read_write, + _IO_NO_READS+_IO_NO_WRITES+_IO_IS_APPENDING); + + return (_IO_FILE *) fp; +} + +weak_alias (_IO_fdopen, fdopen) |