File:  [gforth] / gforth / more.fs
Revision 1.2: download - view: text, annotated - select for diffs
Sat Sep 23 15:46:58 2000 UTC (23 years, 6 months ago) by anton
Branches: MAIN
CVS tags: v0-5-0, HEAD
changed FSF address in copyright messages

\ Forth output paging add-on (like more(1))

\ Copyright (C) 1996 Free Software Foundation, Inc.

\ This file is part of Gforth.

\ Gforth 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
\ of the License, or (at your option) any later version.

\ This program 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 program; if not, write to the Free Software
\ Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.


\ This add-on is for those poor souls whose terminals cannot scroll
\ back but who want to read the output of 'words' at their leisure.

\ currently this is very primitive: it just counts newlines, and only
\ allows continuing for another page (and of course, terminating
\ processing by sending a signal (^C))

\ Some things to do:
\ allow continuing for one line (Enter)
\ count lines produced by wraparound (note tabs and backspaces)
\ allow continuing silently
\ fancy features like searching, scrollback etc.

\ one more-or-less simple way to achieve all this is to
\ popen("less","w") and output there. Before getting the next `key`,
\ we would perform a pclose. This idea due to Marcel Hendrix.

require termsize.fs

variable last-#lines 0 last-#lines !

:noname ( -- c )
    1 last-#lines !
    defers key ;
is key

:noname ( c -- )
    dup defers emit
    #lf =
    if
	1 last-#lines +!
	last-#lines @ rows >=
	if
	    ." ... more ?" key drop 10 backspaces 10 spaces 10 backspaces
	endif
    endif ;
is emit

:noname ( c-addr u -- )
    bounds
    ?DO
	I c@ emit
    LOOP ;
is type

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