_IO_FILE * _IO_new_fdopen (int fd, const char *mode) { int read_write; struct locked_FILE { struct _IO_FILE_plus fp; #ifdef _IO_MTSAFE_IO _IO_lock_t lock; #endif struct _IO_wide_data wd; } *new_f; int i; int use_mmap = 0; /* Decide whether we modify the offset of the file we attach to and seek to the end of file. We only do this if the mode is 'a' and if the file descriptor did not have O_APPEND in its flags already. */ bool do_seek = false; switch (*mode) { case 'r': read_write = _IO_NO_WRITES; break; case 'w': read_write = _IO_NO_READS; break; case 'a': read_write = _IO_NO_READS|_IO_IS_APPENDING; break; default: MAYBE_SET_EINVAL; return NULL; } for (i = 1; i < 5; ++i) { switch (*++mode) { case '\0': break; case '+': read_write &= _IO_IS_APPENDING; break; case 'm': use_mmap = 1; continue; case 'x': case 'b': default: /* Ignore */ continue; } break; } #ifdef F_GETFL int fd_flags = _IO_fcntl (fd, F_GETFL); #ifndef O_ACCMODE #define O_ACCMODE (O_RDONLY|O_WRONLY|O_RDWR) #endif if (fd_flags == -1) return NULL; if (((fd_flags & O_ACCMODE) == O_RDONLY && !(read_write & _IO_NO_WRITES)) || ((fd_flags & O_ACCMODE) == O_WRONLY && !(read_write & _IO_NO_READS))) { MAYBE_SET_EINVAL; 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 ((read_write & _IO_IS_APPENDING) && !(fd_flags & O_APPEND)) { do_seek = true; #ifdef F_SETFL if (_IO_fcntl (fd, F_SETFL, fd_flags | O_APPEND) == -1) #endif return NULL; } #endif new_f = (struct locked_FILE *) malloc (sizeof (struct locked_FILE)); if (new_f == NULL) return NULL; #ifdef _IO_MTSAFE_IO new_f->fp.file._lock = &new_f->lock; #endif _IO_no_init (&new_f->fp.file, 0, 0, &new_f->wd, #ifdef _G_HAVE_MMAP (use_mmap && (read_write & _IO_NO_WRITES)) ? &_IO_wfile_jumps_maybe_mmap : #endif &_IO_wfile_jumps); _IO_JUMPS (&new_f->fp) = #ifdef _G_HAVE_MMAP (use_mmap && (read_write & _IO_NO_WRITES)) ? &_IO_file_jumps_maybe_mmap : #endif &_IO_file_jumps; _IO_new_file_init_internal (&new_f->fp); #if !_IO_UNIFIED_JUMPTABLES new_f->fp.vtable = NULL; #endif /* We only need to record the fd because _IO_file_init_internal will have unset the offset. It is important to unset the cached offset because the real offset in the file could change between now and when the handle is activated and we would then mislead ftell into believing that we have a valid offset. */ new_f->fp.file._fileno = fd; new_f->fp.file._flags &= ~_IO_DELETE_DONT_CLOSE; _IO_mask_flags (&new_f->fp.file, read_write, _IO_NO_READS+_IO_NO_WRITES+_IO_IS_APPENDING); /* For append mode, set the file offset to the end of the file if we added O_APPEND to the file descriptor flags. Don't update the offset cache though, since the file handle is not active. */ if (do_seek && ((read_write & (_IO_IS_APPENDING | _IO_NO_READS)) == (_IO_IS_APPENDING | _IO_NO_READS))) { _IO_off64_t new_pos = _IO_SYSSEEK (&new_f->fp.file, 0, _IO_seek_end); if (new_pos == _IO_pos_BAD && errno != ESPIPE) return NULL; } return &new_f->fp.file; }
attribute_compat_text_section _IO_old_fdopen (int fd, const char *mode) { int read_write; int posix_mode = 0; struct locked_FILE { struct _IO_FILE_complete_plus fp; #ifdef _IO_MTSAFE_IO _IO_lock_t lock; #endif } *new_f; 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: MAYBE_SET_EINVAL; 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 new_f = (struct locked_FILE *) malloc (sizeof (struct locked_FILE)); if (new_f == NULL) return NULL; #ifdef _IO_MTSAFE_IO new_f->fp.file._file._lock = &new_f->lock; #endif _IO_old_init (&new_f->fp.file._file, 0); _IO_JUMPS_FILE_plus (&new_f->fp) = &_IO_old_file_jumps; _IO_old_file_init ((struct _IO_FILE_plus *) &new_f->fp); #if !_IO_UNIFIED_JUMPTABLES new_f->fp.vtable = NULL; #endif if (_IO_old_file_attach (&new_f->fp.file._file, fd) == NULL) { _IO_un_link ((struct _IO_FILE_plus *) &new_f->fp); free (new_f); return NULL; } new_f->fp.file._file._flags &= ~_IO_DELETE_DONT_CLOSE; _IO_mask_flags (&new_f->fp.file._file, read_write, _IO_NO_READS+_IO_NO_WRITES+_IO_IS_APPENDING); return (_IO_FILE *) &new_f->fp; }