17.6 The Buffer Object

Buffers contain fields not directly accessible by the Lisp programmer. We describe them here, naming them by the names used in the C code. Many are accessible indirectly in Lisp programs via Lisp primitives.

name

The buffer name is a string that names the buffer. It is guaranteed to be unique. See Buffer Names.

save_modified

This field contains the time when the buffer was last saved, as an integer. See Buffer Modification.

modtime

This field contains the modification time of the visited file. It is set when the file is written or read. Every time the buffer is written to the file, this field is compared to the modification time of the file. See Buffer Modification.

auto_save_modified

This field contains the time when the buffer was last auto-saved.

last_window_start

This field contains the window-start position in the buffer as of the last time the buffer was displayed in a window.

undo_list

This field points to the buffer's undo list. See Undo.

syntax_table_v

This field contains the syntax table for the buffer. See Syntax Tables.

downcase_table

This field contains the conversion table for converting text to lower case. See Case Tables.

upcase_table

This field contains the conversion table for converting text to upper case. See Case Tables.

case_canon_table

This field contains the conversion table for canonicalizing text for case-folding search. See Case Tables.

case_eqv_table

This field contains the equivalence table for case-folding search. See Case Tables.

display_table

This field contains the buffer's display table, or nil if it doesn't have one. See Display Tables.

markers

This field contains the chain of all markers that currently point into the buffer. Deletion of text in the buffer, and motion of the buffer's gap, must check each of these markers and perhaps update it. See Markers.

backed_up

This field is a flag that tells whether a backup file has been made for the visited file of this buffer.

mark

This field contains the mark for the buffer. The mark is a marker, hence it is also included on the list markers. See The Mark.

mark_active

This field is non-nil if the buffer's mark is active.

local_var_alist

This field contains the association list describing the variables local in this buffer, and their values, with the exception of local variables that have special slots in the buffer object. (Those slots are omitted from this table.) See Buffer-Local Variables.

modeline_format

This field contains a Lisp object which controls how to display the mode line for this buffer. See Modeline Format.

base_buffer

This field holds the buffer's base buffer (if it is an indirect buffer), or nil.