- ESCDELAY and TABSIZE are extensions, not provided in most other imple-
- mentations of curses.
+ TABSIZE is a feature of SVr4 curses which is not documented by X/Open
+ curses.
+
+ o In SVr4 curses, TABSIZE is initially set from the terminal descrip-
+ tion's init_tabs capability. After that, it can be altered by the
+ applications using SVr4 curses.
+
+ SVr4 curses uses the current value of TABSIZE to compute the posi-
+ tion of tabstops for updating both the virtual screen with add-
+ ch(3x) as well as the physical screen with mvcur(3x).
+
+ o This implementation uses the current value of TABSIZE only for up-
+ dating the virtual screen. It uses the terminal description's it
+ (init_tabs) capability for computing hardware tabs (i.e., tab stops
+ on the physical screen).
+
+ o Other implementations differ. For instance, NetBSD curses allows
+ TABSIZE to be set through an environment variable. This implemen-
+ tation does not.
+
+ NetBSD curses does not support hardware tabs; it uses the init_tabs
+ capability and the TABSIZE variable only for updating the virtual
+ screen.
- ESCDELAY is an extension in AIX curses:
+ ESCDELAY is an extension in AIX curses:
- o In AIX, the units for ESCDELAY are fifths of a millisecond.
+ o In AIX, the units for ESCDELAY are fifths of a millisecond.
- o The default value for AIX's ESCDELAY is 0.1 seconds.
+ o The default value for AIX's ESCDELAY is 0.1 seconds.
- o AIX also enforces a limit of 10,000 seconds for ESCDELAY; this im-
+ o AIX also enforces a limit of 10,000 seconds for ESCDELAY; this im-
plementation currently has no upper limit.
- This implementation has long used ESCDELAY with units of milliseconds,
- making it impossible to be completely compatible with AIX. Likewise,
- most users have either decided to override the value, or rely upon its
+ This implementation has long used ESCDELAY with units of milliseconds,
+ making it impossible to be completely compatible with AIX. Likewise,
+ most users have either decided to override the value, or rely upon its
default value.