Annotation of gforth/more.fs, revision 1.5

1.1       anton       1: \ Forth output paging add-on (like more(1))
                      2: 
1.4       anton       3: \ Copyright (C) 1996,2000,2003 Free Software Foundation, Inc.
1.1       anton       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
1.5     ! anton       9: \ as published by the Free Software Foundation, either version 3
1.1       anton      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
1.5     ! anton      18: \ along with this program. If not, see http://www.gnu.org/licenses/.
1.1       anton      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

FreeBSD-CVSweb <freebsd-cvsweb@FreeBSD.org>