File:  [gforth] / gforth / more.fs
Revision 1.6: download - view: text, annotated - select for diffs
Mon Dec 31 19:02:24 2007 UTC (16 years, 3 months ago) by anton
Branches: MAIN
CVS tags: v0-7-0, HEAD
updated copyright year after changing license notice

    1: \ Forth output paging add-on (like more(1))
    2: 
    3: \ Copyright (C) 1996,2000,2003,2007 Free Software Foundation, Inc.
    4: 
    5: \ This file is part of Gforth.
    6: 
    7: \ Gforth is free software; you can redistribute it and/or
    8: \ modify it under the terms of the GNU General Public License
    9: \ as published by the Free Software Foundation, either version 3
   10: \ of the License, or (at your option) any later version.
   11: 
   12: \ This program is distributed in the hope that it will be useful,
   13: \ but WITHOUT ANY WARRANTY; without even the implied warranty of
   14: \ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   15: \ GNU General Public License for more details.
   16: 
   17: \ You should have received a copy of the GNU General Public License
   18: \ along with this program. If not, see http://www.gnu.org/licenses/.
   19: 
   20: 
   21: \ This add-on is for those poor souls whose terminals cannot scroll
   22: \ back but who want to read the output of 'words' at their leisure.
   23: 
   24: \ currently this is very primitive: it just counts newlines, and only
   25: \ allows continuing for another page (and of course, terminating
   26: \ processing by sending a signal (^C))
   27: 
   28: \ Some things to do:
   29: \ allow continuing for one line (Enter)
   30: \ count lines produced by wraparound (note tabs and backspaces)
   31: \ allow continuing silently
   32: \ fancy features like searching, scrollback etc.
   33: 
   34: \ one more-or-less simple way to achieve all this is to
   35: \ popen("less","w") and output there. Before getting the next `key`,
   36: \ we would perform a pclose. This idea due to Marcel Hendrix.
   37: 
   38: require termsize.fs
   39: 
   40: variable last-#lines 0 last-#lines !
   41: 
   42: :noname ( -- c )
   43:     1 last-#lines !
   44:     defers key ;
   45: is key
   46: 
   47: :noname ( c -- )
   48:     dup defers emit
   49:     #lf =
   50:     if
   51: 	1 last-#lines +!
   52: 	last-#lines @ rows >=
   53: 	if
   54: 	    ." ... more ?" key drop 10 backspaces 10 spaces 10 backspaces
   55: 	endif
   56:     endif ;
   57: is emit
   58: 
   59: :noname ( c-addr u -- )
   60:     bounds
   61:     ?DO
   62: 	I c@ emit
   63:     LOOP ;
   64: is type

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