_IO_FILE * _IO_file_open (_IO_FILE *fp, const char *filename, int posix_mode, int prot, int read_write, int is32not64) { int fdesc; #ifdef _LIBC if (__glibc_unlikely (fp->_flags2 & _IO_FLAGS2_NOTCANCEL)) fdesc = open_not_cancel (filename, posix_mode | (is32not64 ? 0 : O_LARGEFILE), prot); else fdesc = open (filename, posix_mode | (is32not64 ? 0 : O_LARGEFILE), prot); #else fdesc = open (filename, posix_mode, prot); #endif if (fdesc < 0) return NULL; fp->_fileno = fdesc; _IO_mask_flags (fp, read_write,_IO_NO_READS+_IO_NO_WRITES+_IO_IS_APPENDING); /* For append mode, send the file offset to the end of the file. Don't update the offset cache though, since the file handle is not active. */ if ((read_write & (_IO_IS_APPENDING | _IO_NO_READS)) == (_IO_IS_APPENDING | _IO_NO_READS)) { _IO_off64_t new_pos = _IO_SYSSEEK (fp, 0, _IO_seek_end); if (new_pos == _IO_pos_BAD && errno != ESPIPE) { close_not_cancel (fdesc); return NULL; } } _IO_link_in ((struct _IO_FILE_plus *) fp); return fp; }
int _IO_vdprintf (int d, const char *format, _IO_va_list arg) { struct _IO_FILE_plus tmpfil; struct _IO_wide_data wd; int done; #ifdef _IO_MTSAFE_IO tmpfil.file._lock = NULL; #endif _IO_no_init (&tmpfil.file, _IO_USER_LOCK, 0, &wd, &_IO_wfile_jumps); _IO_JUMPS (&tmpfil) = &_IO_file_jumps; _IO_new_file_init_internal (&tmpfil); #if !_IO_UNIFIED_JUMPTABLES tmpfil.vtable = NULL; #endif if (_IO_file_attach (&tmpfil.file, d) == NULL) { _IO_un_link (&tmpfil); return EOF; } tmpfil.file._flags |= _IO_DELETE_DONT_CLOSE; _IO_mask_flags (&tmpfil.file, _IO_NO_READS, _IO_NO_READS+_IO_NO_WRITES+_IO_IS_APPENDING); done = _IO_vfprintf (&tmpfil.file, format, arg); if (done != EOF && _IO_do_flush (&tmpfil.file) == EOF) done = EOF; _IO_FINISH (&tmpfil.file); return done; }
int __vdprintf_chk (int d, int flags, const char *format, va_list arg) { struct _IO_FILE_plus tmpfil; struct _IO_wide_data wd; int done; #ifdef _IO_MTSAFE_IO tmpfil.file._lock = NULL; #endif _IO_no_init (&tmpfil.file, _IO_USER_LOCK, 0, &wd, &_IO_wfile_jumps); _IO_JUMPS (&tmpfil) = &_IO_file_jumps; _IO_new_file_init_internal (&tmpfil); if (_IO_file_attach (&tmpfil.file, d) == NULL) { _IO_un_link (&tmpfil); return EOF; } tmpfil.file._flags |= _IO_DELETE_DONT_CLOSE; _IO_mask_flags (&tmpfil.file, _IO_NO_READS, _IO_NO_READS+_IO_NO_WRITES+_IO_IS_APPENDING); /* For flags > 0 (i.e. __USE_FORTIFY_LEVEL > 1) request that %n can only come from read-only format strings. */ if (flags > 0) tmpfil.file._flags2 |= _IO_FLAGS2_FORTIFY; done = _IO_vfprintf (&tmpfil.file, format, arg); _IO_FINISH (&tmpfil.file); return done; }
_IO_off64_t _IO_file_seekoff_mmap (_IO_FILE *fp, _IO_off64_t offset, int dir, int mode) { _IO_off64_t result; /* If we are only interested in the current position, calculate it and return right now. This calculation does the right thing when we are using a pushback buffer, but in the usual case has the same value as (fp->_IO_read_ptr - fp->_IO_buf_base). */ if (mode == 0) return fp->_offset - (fp->_IO_read_end - fp->_IO_read_ptr); switch (dir) { case _IO_seek_cur: /* Adjust for read-ahead (bytes is buffer). */ offset += fp->_IO_read_ptr - fp->_IO_read_base; break; case _IO_seek_set: break; case _IO_seek_end: offset += fp->_IO_buf_end - fp->_IO_buf_base; break; } /* At this point, dir==_IO_seek_set. */ if (offset < 0) { /* No negative offsets are valid. */ __set_errno (EINVAL); return EOF; } result = _IO_SYSSEEK (fp, offset, 0); if (result < 0) return EOF; if (offset > fp->_IO_buf_end - fp->_IO_buf_base) /* One can fseek arbitrarily past the end of the file and it is meaningless until one attempts to read. Leave the buffer pointers in EOF state until underflow. */ _IO_setg (fp, fp->_IO_buf_base, fp->_IO_buf_end, fp->_IO_buf_end); else /* Adjust the read pointers to match the file position, but so the next read attempt will call underflow. */ _IO_setg (fp, fp->_IO_buf_base, fp->_IO_buf_base + offset, fp->_IO_buf_base + offset); fp->_offset = result; _IO_mask_flags (fp, 0, _IO_EOF_SEEN); return offset; }
attribute_compat_text_section _IO_old_file_fopen (_IO_FILE *fp, const char *filename, const char *mode) { int oflags = 0, omode; int read_write, fdesc; int oprot = 0666; if (_IO_file_is_open (fp)) return 0; switch (*mode++) { case 'r': omode = O_RDONLY; read_write = _IO_NO_WRITES; break; case 'w': omode = O_WRONLY; oflags = O_CREAT|O_TRUNC; read_write = _IO_NO_READS; break; case 'a': omode = O_WRONLY; oflags = O_CREAT|O_APPEND; read_write = _IO_NO_READS|_IO_IS_APPENDING; break; default: __set_errno (EINVAL); return NULL; } if (mode[0] == '+' || (mode[0] == 'b' && mode[1] == '+')) { omode = O_RDWR; read_write &= _IO_IS_APPENDING; } fdesc = open (filename, omode|oflags, oprot); if (fdesc < 0) return NULL; fp->_fileno = fdesc; _IO_mask_flags (fp, read_write,_IO_NO_READS+_IO_NO_WRITES+_IO_IS_APPENDING); if (read_write & _IO_IS_APPENDING) if (_IO_SEEKOFF (fp, (_IO_off_t)0, _IO_seek_end, _IOS_INPUT|_IOS_OUTPUT) == _IO_pos_BAD && errno != ESPIPE) return NULL; _IO_link_in ((struct _IO_FILE_plus *) fp); return fp; }
void _IO_cookie_init (struct _IO_cookie_file *cfile, int read_write, void *cookie, _IO_cookie_io_functions_t io_functions) { _IO_init_internal (&cfile->__fp.file, 0); _IO_JUMPS (&cfile->__fp) = &_IO_cookie_jumps; cfile->__cookie = cookie; set_callbacks (&cfile->__io_functions, io_functions); _IO_new_file_init_internal (&cfile->__fp); _IO_mask_flags (&cfile->__fp.file, read_write, _IO_NO_READS+_IO_NO_WRITES+_IO_IS_APPENDING); /* We use a negative number different from -1 for _fileno to mark that this special stream is not associated with a real file, but still has to be treated as such. */ cfile->__fp.file._fileno = -2; }
_IO_off64_t attribute_compat_text_section _IO_old_file_seekoff (_IO_FILE *fp, _IO_off64_t offset, int dir, int mode) { _IO_off_t result; _IO_off64_t delta, new_offset; long count; /* POSIX.1 8.2.3.7 says that after a call the fflush() the file offset of the underlying file must be exact. */ int must_be_exact = (fp->_IO_read_base == fp->_IO_read_end && fp->_IO_write_base == fp->_IO_write_ptr); if (mode == 0) dir = _IO_seek_cur, offset = 0; /* Don't move any pointers. */ /* Flush unwritten characters. (This may do an unneeded write if we seek within the buffer. But to be able to switch to reading, we would need to set egptr to pptr. That can't be done in the current design, which assumes file_ptr() is eGptr. Anyway, since we probably end up flushing when we close(), it doesn't make much difference.) FIXME: simulate mem-mapped files. */ if (fp->_IO_write_ptr > fp->_IO_write_base || _IO_in_put_mode (fp)) if (_IO_switch_to_get_mode (fp)) return EOF; if (fp->_IO_buf_base == NULL) { /* It could be that we already have a pushback buffer. */ if (fp->_IO_read_base != NULL) { free (fp->_IO_read_base); fp->_flags &= ~_IO_IN_BACKUP; } _IO_doallocbuf (fp); _IO_setp (fp, fp->_IO_buf_base, fp->_IO_buf_base); _IO_setg (fp, fp->_IO_buf_base, fp->_IO_buf_base, fp->_IO_buf_base); } switch (dir) { case _IO_seek_cur: /* Adjust for read-ahead (bytes is buffer). */ offset -= fp->_IO_read_end - fp->_IO_read_ptr; if (fp->_old_offset == _IO_pos_BAD) goto dumb; /* Make offset absolute, assuming current pointer is file_ptr(). */ offset += fp->_old_offset; dir = _IO_seek_set; break; case _IO_seek_set: break; case _IO_seek_end: { struct stat64 st; if (_IO_SYSSTAT (fp, &st) == 0 && S_ISREG (st.st_mode)) { offset += st.st_size; dir = _IO_seek_set; } else goto dumb; } } /* At this point, dir==_IO_seek_set. */ /* If we are only interested in the current position we've found it now. */ if (mode == 0) return offset; /* If destination is within current buffer, optimize: */ if (fp->_old_offset != _IO_pos_BAD && fp->_IO_read_base != NULL && !_IO_in_backup (fp)) { /* Offset relative to start of main get area. */ _IO_off_t rel_offset = (offset - fp->_old_offset + (fp->_IO_read_end - fp->_IO_read_base)); if (rel_offset >= 0) { #if 0 if (_IO_in_backup (fp)) _IO_switch_to_main_get_area (fp); #endif if (rel_offset <= fp->_IO_read_end - fp->_IO_read_base) { _IO_setg (fp, fp->_IO_buf_base, fp->_IO_buf_base + rel_offset, fp->_IO_read_end); _IO_setp (fp, fp->_IO_buf_base, fp->_IO_buf_base); { _IO_mask_flags (fp, 0, _IO_EOF_SEEN); goto resync; } } #ifdef TODO /* If we have streammarkers, seek forward by reading ahead. */ if (_IO_have_markers (fp)) { int to_skip = rel_offset - (fp->_IO_read_ptr - fp->_IO_read_base); if (ignore (to_skip) != to_skip) goto dumb; _IO_mask_flags (fp, 0, _IO_EOF_SEEN); goto resync; } #endif } #ifdef TODO if (rel_offset < 0 && rel_offset >= Bbase () - Bptr ()) { if (!_IO_in_backup (fp)) _IO_switch_to_backup_area (fp); gbump (fp->_IO_read_end + rel_offset - fp->_IO_read_ptr); _IO_mask_flags (fp, 0, _IO_EOF_SEEN); goto resync; } #endif } #ifdef TODO _IO_unsave_markers (fp); #endif if (fp->_flags & _IO_NO_READS) goto dumb; /* Try to seek to a block boundary, to improve kernel page management. */ new_offset = offset & ~(fp->_IO_buf_end - fp->_IO_buf_base - 1); delta = offset - new_offset; if (delta > fp->_IO_buf_end - fp->_IO_buf_base) { new_offset = offset; delta = 0; } result = _IO_SYSSEEK (fp, new_offset, 0); if (result < 0) return EOF; if (delta == 0) count = 0; else { count = _IO_SYSREAD (fp, fp->_IO_buf_base, (must_be_exact ? delta : fp->_IO_buf_end - fp->_IO_buf_base)); if (count < delta) { /* We weren't allowed to read, but try to seek the remainder. */ offset = count == EOF ? delta : delta-count; dir = _IO_seek_cur; goto dumb; } } _IO_setg (fp, fp->_IO_buf_base, fp->_IO_buf_base + delta, fp->_IO_buf_base + count); _IO_setp (fp, fp->_IO_buf_base, fp->_IO_buf_base); fp->_old_offset = result + count; _IO_mask_flags (fp, 0, _IO_EOF_SEEN); return offset; dumb: _IO_unsave_markers (fp); result = _IO_SYSSEEK (fp, offset, dir); if (result != EOF) { _IO_mask_flags (fp, 0, _IO_EOF_SEEN); fp->_old_offset = result; _IO_setg (fp, fp->_IO_buf_base, fp->_IO_buf_base, fp->_IO_buf_base); _IO_setp (fp, fp->_IO_buf_base, fp->_IO_buf_base); } return result; resync: /* We need to do it since it is possible that the file offset in the kernel may be changed behind our back. It may happen when we fopen a file and then do a fork. One process may access the file and the kernel file offset will be changed. */ if (fp->_old_offset >= 0) _IO_SYSSEEK (fp, fp->_old_offset, 0); return offset; }
_IO_off64_t _IO_new_file_seekoff (_IO_FILE *fp, _IO_off64_t offset, int dir, int mode) { _IO_off64_t result; _IO_off64_t delta, new_offset; long count; /* Short-circuit into a separate function. We don't want to mix any functionality and we don't want to touch anything inside the FILE object. */ if (mode == 0) return do_ftell (fp); /* POSIX.1 8.2.3.7 says that after a call the fflush() the file offset of the underlying file must be exact. */ int must_be_exact = (fp->_IO_read_base == fp->_IO_read_end && fp->_IO_write_base == fp->_IO_write_ptr); bool was_writing = (fp->_IO_write_ptr > fp->_IO_write_base || _IO_in_put_mode (fp)); /* Flush unwritten characters. (This may do an unneeded write if we seek within the buffer. But to be able to switch to reading, we would need to set egptr to pptr. That can't be done in the current design, which assumes file_ptr() is eGptr. Anyway, since we probably end up flushing when we close(), it doesn't make much difference.) FIXME: simulate mem-mapped files. */ if (was_writing && _IO_switch_to_get_mode (fp)) return EOF; if (fp->_IO_buf_base == NULL) { /* It could be that we already have a pushback buffer. */ if (fp->_IO_read_base != NULL) { free (fp->_IO_read_base); fp->_flags &= ~_IO_IN_BACKUP; } _IO_doallocbuf (fp); _IO_setp (fp, fp->_IO_buf_base, fp->_IO_buf_base); _IO_setg (fp, fp->_IO_buf_base, fp->_IO_buf_base, fp->_IO_buf_base); } switch (dir) { case _IO_seek_cur: /* Adjust for read-ahead (bytes is buffer). */ offset -= fp->_IO_read_end - fp->_IO_read_ptr; if (fp->_offset == _IO_pos_BAD) goto dumb; /* Make offset absolute, assuming current pointer is file_ptr(). */ offset += fp->_offset; if (offset < 0) { __set_errno (EINVAL); return EOF; } dir = _IO_seek_set; break; case _IO_seek_set: break; case _IO_seek_end: { struct stat64 st; if (_IO_SYSSTAT (fp, &st) == 0 && S_ISREG (st.st_mode)) { offset += st.st_size; dir = _IO_seek_set; } else goto dumb; } } /* At this point, dir==_IO_seek_set. */ /* If destination is within current buffer, optimize: */ if (fp->_offset != _IO_pos_BAD && fp->_IO_read_base != NULL && !_IO_in_backup (fp)) { _IO_off64_t start_offset = (fp->_offset - (fp->_IO_read_end - fp->_IO_buf_base)); if (offset >= start_offset && offset < fp->_offset) { _IO_setg (fp, fp->_IO_buf_base, fp->_IO_buf_base + (offset - start_offset), fp->_IO_read_end); _IO_setp (fp, fp->_IO_buf_base, fp->_IO_buf_base); _IO_mask_flags (fp, 0, _IO_EOF_SEEN); goto resync; } } if (fp->_flags & _IO_NO_READS) goto dumb; /* Try to seek to a block boundary, to improve kernel page management. */ new_offset = offset & ~(fp->_IO_buf_end - fp->_IO_buf_base - 1); delta = offset - new_offset; if (delta > fp->_IO_buf_end - fp->_IO_buf_base) { new_offset = offset; delta = 0; } result = _IO_SYSSEEK (fp, new_offset, 0); if (result < 0) return EOF; if (delta == 0) count = 0; else { count = _IO_SYSREAD (fp, fp->_IO_buf_base, (must_be_exact ? delta : fp->_IO_buf_end - fp->_IO_buf_base)); if (count < delta) { /* We weren't allowed to read, but try to seek the remainder. */ offset = count == EOF ? delta : delta-count; dir = _IO_seek_cur; goto dumb; } } _IO_setg (fp, fp->_IO_buf_base, fp->_IO_buf_base + delta, fp->_IO_buf_base + count); _IO_setp (fp, fp->_IO_buf_base, fp->_IO_buf_base); fp->_offset = result + count; _IO_mask_flags (fp, 0, _IO_EOF_SEEN); return offset; dumb: _IO_unsave_markers (fp); result = _IO_SYSSEEK (fp, offset, dir); if (result != EOF) { _IO_mask_flags (fp, 0, _IO_EOF_SEEN); fp->_offset = result; _IO_setg (fp, fp->_IO_buf_base, fp->_IO_buf_base, fp->_IO_buf_base); _IO_setp (fp, fp->_IO_buf_base, fp->_IO_buf_base); } return result; resync: /* We need to do it since it is possible that the file offset in the kernel may be changed behind our back. It may happen when we fopen a file and then do a fork. One process may access the file and the kernel file offset will be changed. */ if (fp->_offset >= 0) _IO_SYSSEEK (fp, fp->_offset, 0); return offset; }
_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; }
_IO_FILE * _IO_new_fdopen (int fd, const char *mode) { int read_write; int posix_mode = 0; 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 fd_flags; int i; int use_mmap = 0; 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; } 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 fd_flags = 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 ((posix_mode & O_APPEND) && !(fd_flags & O_APPEND)) { #ifdef F_SETFL if (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 /* Set up initially to use the `maybe_mmap' jump tables rather than using __fopen_maybe_mmap to do it, because we need them in place before we call _IO_file_attach or else it will allocate a buffer immediately. */ _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 &INTUSE(_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 &INTUSE(_IO_file_jumps); INTUSE(_IO_file_init) (&new_f->fp); #if !_IO_UNIFIED_JUMPTABLES new_f->fp.vtable = NULL; #endif if (INTUSE(_IO_file_attach) ((_IO_FILE *) &new_f->fp, fd) == NULL) { INTUSE(_IO_setb) (&new_f->fp.file, NULL, NULL, 0); INTUSE(_IO_un_link) (&new_f->fp); free (new_f); return NULL; } new_f->fp.file._flags &= ~_IO_DELETE_DONT_CLOSE; new_f->fp.file._IO_file_flags = _IO_mask_flags (&new_f->fp.file, read_write, _IO_NO_READS+_IO_NO_WRITES+_IO_IS_APPENDING); return &new_f->fp.file; }