Source Code 1994 March/Source_Code_CD-ROM_Walnut_Creek_March_1994.iso/compsrcs/misc/volume33/problem/part04

Text File | 1992-10-18 | 48.3 KB | 1,730 lines

Newsgroups: comp.sources.misc
From: [e-mail] (Mike Lijewski)
Subject:  v33i006:  problem - A Problem Database Manager, Part04/07
Message-ID: <[e-mail]>
X-Md4-Signature: 463719d06e07eaf6f9695031a25ab8fd
Date: Mon, 19 Oct 1992 16:58:56 GMT
Approved: [e-mail]

Submitted-by: [e-mail] (Mike Lijewski)
Posting-number: Volume 33, Issue 6
Archive-name: problem/part04
Environment: UNIX, GDBM, C++, termcap

#! /bin/sh
# This is a shell archive.  Remove anything before this line, then unpack
# it by saving it into a file and typing "sh file".  To overwrite existing
# files, type "sh file -c".  You can also feed this as standard input via
# unshar, or by typing "sh <file", e.g..  If this archive is complete, you
# will see the following message at the end:
#        "End of archive 4 (of 7)."
# Contents:  classes.C lister.C
# Wrapped by lijewski@xtesoc2 on Mon Oct 19 11:05:10 1992
PATH=/bin:/usr/bin:/usr/ucb ; export PATH
if test -f 'classes.C' -a "${1}" != "-c" ; then
  echo shar: Will not clobber existing file \"'classes.C'\"
else
echo shar: Extracting \"'classes.C'\" \(7402 characters\)
sed "s/^X//" >'classes.C' <<'END_OF_FILE'
X/*
X** classes.C - contains definitions of the member functions which
X**             aren\'t defined in the relevant class declarations.
X**
X** classes.C classes.C 1.9   Delta\'d: 12:28:24 9/23/92   Mike Lijewski, CNSF
X**
X** Copyright \(c\) 1991, 1992 Cornell University
X** All rights reserved.
X**
X** Redistribution and use in source and binary forms are permitted
X** provided that: \(1\) source distributions retain this entire copyright
X** notice and comment, and \(2\) distributions including binaries display
X** the following acknowledgement:  ``This product includes software
X** developed by Cornell University\'\' in the documentation or other
X** materials provided with the distribution and in all advertising
X** materials mentioning features or use of this software. Neither the
X** name of the University nor the names of its contributors may be used
X** to endorse or promote products derived from this software without
X** specific prior written permission.
X**
X** THIS SOFTWARE IS PROVIDED ``AS IS\'\' AND WITHOUT ANY EXPRESS OR
X** IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
X** WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
X*/
X
X#include <new.h>
X#include <stdlib.h>
X#include <string.h>
X
X#include "classes.h"
X#include "utilities.h"
X
Xtypedef void (*PEHF)();
X
XStringRep::StringRep()
X{
X    rep = ::new char[1];
X    len = 0;
X    *rep = '\0';
X    count = 1;
X}
X
XStringRep::StringRep(const char *s)
X{
X    len = ::strlen(s);
X    rep = ::new char[len + 1];
X    ::strcpy(rep, s);
X    count = 1;
X}
X
XString StringRep::operator+(const String& s) const
X{
X    size_t slen  = s.length() + length();
X    char *buf    = ::new char[slen + 1];
X    ::strcpy(buf, rep);
X    ::strcat(buf, s.p->rep);
X    return String(&buf, slen);
X}
X
X/*
X** The definition of the head of the freelist that StringRep::operator new\(\)
X** uses to dole out StringReps efficiently.
X*/
X
XStringRep *StringRep::freeList;
X
Xvoid* StringRep::operator new(size_t size)
X{
X    if (size != sizeof(StringRep)) return ::new char[size];
X    StringRep *s = freeList;
X    if (s)
X        freeList = s->next;
X    else
X    {
X        StringRep *block = (StringRep*)::new char[chunksize*sizeof(StringRep)];
X        if (block == 0)
X        {
X            PEHF newHandler = set_new_handler(0);
X            set_new_handler(newHandler);
X            if (newHandler)
X                newHandler();
X            else
X                return 0;
X        }
X        for (int i = 0; i < chunksize - 1; i++)
X            block[i].next = (StringRep *)&block[i + 1];
X        block[chunksize - 1].next = 0;
X        s = block;
X        freeList = &block[1];
X    }
X    return s;
X}
X
Xvoid StringRep::operator delete(void *object)
X{
X    StringRep *s = (StringRep *)object;
X    s->next = freeList;
X    freeList = s;
X}
X
XString::~String() { if (--p->count <= 0) delete p; }
X
XString& String::operator=(const String& rhs)
X{
X    rhs.p->count++;
X    if (--p->count <= 0) delete p;
X    p = rhs.p;
X    return *this;
X}
X
Xvoid String::operator+=(const String& rhs)
X{
X    size_t slen = p->length() + rhs.length();
X    char *buf   = ::new char[slen + 1];
X    (void)strcpy(buf, p->rep);
X    (void)strcat(buf, rhs.p->rep);
X    if (p->count == 1)
X    {
X        DELETE p->rep;
X        p->rep = buf;
X        p->len = slen;
X    }
X    else
X        operator=(String(&buf, slen));
X}
X
Xvoid String::operator+=(const char *rhs)
X{
X    size_t slen = p->length() + ::strlen(rhs);
X    char *buf = ::new char[slen + 1];
X    ::strcpy(buf, p->rep);
X    ::strcat(buf, rhs);
X    if (p->count == 1)
X    {
X        DELETE p->rep;
X        p->rep = buf;
X        p->len = slen;
X    }
X    else
X        operator=(String(&buf, slen));
X}
X
Xvoid String::range_error(int index)
X{
X    ::error("range error: %d out of bounds", index);
X    exit(1);
X}
X
XSBHelper String::operator[](int index)
X{
X    if (index < 0 || index >= length()) range_error(index);
X    return SBHelper(*this, index);
X}
X
XSBHelper::SBHelper(String& s, int i) : str(s), index(i) { };
X
Xchar SBHelper::operator=(char c)
X{
X    if (str.p->count == 1)
X        //
X        // Only one reference to our String.  Just assign the character to
X        // the appropriate place.  Note that String::operator\[\] does the
X        // range checking.
X        //
X        str.p->rep[index] = c;
X    else
X    {
X        // We have to uniquify our str.
X        str = String(str.p->rep);
X        str.p->rep[index] = c;
X    }
X    return c;
X}
X
XDLink::DLink(char **line) : _line(line) { _next = _prev = 0; }
X
X//
X// Update the line in DLink with a new version.  The new
X// line should have been been allocated via new\(\).
X//
Xvoid DLink::update(char **new_line) { _line = String(new_line); }
X
XDList::DList()
X{
X    _head   = _tail = 0;
X    _next   = _prev = 0;
X    _firstLine = _lastLine = _currLine = 0;
X    _nelems    = _saved_x  = _saved_y  = 0;
X}
X
X//
X// Adds the DLink to the listing maintained by DList.
X//
X
Xvoid DList::add(DLink *link)
X{
X    if (nelems())
X    {
X        _tail->_next = link;
X        _tail->_next->_prev = tail();
X        _tail = link;
X        _nelems++;
X    }
X    else
X    {
X        _head = _tail = link;
X        _nelems = 1;
X    }
X}
X
X//
X// Delete the current listing line in the window
X// and update our view.  The width of our view
X// always decreases by one.  If the calling procedure
X// adds more lines to the screen, they\'ll have to reset
X// lastLine\(\) and/or firstLine\(\), but currLine doesn\'t need to change.
X//
X
Xvoid DList::deleteLine()
X{
X    DLink *line = currLine();
X
X    if (atBegOfList())
X    {
X        //
X        // that is, firstLine\(\) == head\(\)
X        //
X        _head = _firstLine = _currLine = head()->next();
X        _head->_prev = 0;
X    }
X    else if (atWindowTop())
X    {
X        //
X        // but firstLine\(\) != head\(\)
X        //
X        _firstLine = _currLine = line->next();
X        line->_next->_prev = line->prev();
X        line->_prev->_next = line->next();
X    }
X    else if (atEndOfList())
X    {
X        //
X        // lastLine\(\) == tail\(\)
X        //
X        _tail = _lastLine = _currLine = line->prev();
X        _tail->_next = 0;
X    }
X    else
X    {
X        _currLine = line->next();
X        line->_next->_prev = line->prev();
X        line->_prev->_next = line->next();
X    }
X
X    _nelems--;
X    delete line;
X}
X
XDList::~DList()
X{
X    if (nelems())
X    {
X        DLink *tmp = tail(), *prev = tail()->prev();
X        while(tmp)
X        {
X            delete tmp;
X            if ((tmp = prev) != 0) prev = tmp->prev();
X        }
X        delete tmp;
X    }
X}
X
X//
X// The definition of the head of the freelist that DLink::operator new\(\)
X// uses to dole out dirLines efficiently.
X//
XDLink *DLink::freeList;
X
Xvoid *DLink::operator new(size_t)
X{
X    DLink *line = freeList;
X    if (line)
X        freeList = line->next();
X    else
X    {
X        DLink *block = (DLink *) ::new char[chunksize * sizeof(DLink)];
X        if (block == 0)
X        {
X            PEHF newHandler = set_new_handler(0);
X            set_new_handler(newHandler);
X            if (newHandler)
X                newHandler();
X            else
X                return 0;
X        }
X        for (int i = 0; i < chunksize - 1; i++)
X            block[i]._next = (DLink *)&block[i + 1];
X        block[chunksize - 1]._next = 0;
X        line = block;
X        freeList = &block[1];
X    }
X    return line;
X}
X
Xvoid DLink::operator delete(void *object)
X{
X    DLink *line = (DLink *)object;
X    line->_next = freeList;
X    freeList = line;
X}
X
X
END_OF_FILE
if test 7402 -ne `wc -c <'classes.C'`; then
    echo shar: \"'classes.C'\" unpacked with wrong size!
fi
# end of 'classes.C'
fi
if test -f 'lister.C' -a "${1}" != "-c" ; then
  echo shar: Will not clobber existing file \"'lister.C'\"
else
echo shar: Extracting \"'lister.C'\" \(38236 characters\)
sed "s/^X//" >'lister.C' <<'END_OF_FILE'
X/*
X** lister.C - a very simple line lister which manages it\'s own screen
X**            and provides functions which can be executed on the line
X**            the cursor is on -- the "current" line.
X**
X** lister.C 1.25   Delta\'d: 17:43:17 10/8/92   Mike Lijewski, CNSF
X**
X** Copyright \(c\) 1991, 1992 Cornell University
X** All rights reserved.
X**
X** Redistribution and use in source and binary forms are permitted
X** provided that: \(1\) source distributions retain this entire copyright
X** notice and comment, and \(2\) distributions including binaries display
X** the following acknowledgement:  ``This product includes software
X** developed by Cornell University\'\' in the documentation or other
X** materials provided with the distribution and in all advertising
X** materials mentioning features or use of this software. Neither the
X** name of the University nor the names of its contributors may be used
X** to endorse or promote products derived from this software without
X** specific prior written permission.
X**
X** THIS SOFTWARE IS PROVIDED ``AS IS\'\' AND WITHOUT ANY EXPRESS OR
X** IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
X** WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
X*/
X
X
X#include <ctype.h>
X
X#ifndef _IBMR2
X#include <libc.h>
X#endif
X
X#include <osfcn.h>
X#include <signal.h>
X#include <stdio.h>
X#include <stdlib.h>
X#include <string.h>
X#include <sys/types.h>
X#ifdef ESIX
Xtypedef int pid_t;
X#endif /*ESIX*/
X#include <sys/wait.h>
X#include <unistd.h>
X
X#include "classes.h"
X#include "display.h"
X#include "help.h"
X#include "keys.h"
X#include "lister.h"
X#include "problem.h"
X#include "utilities.h"
X#include "version.h"
X
X// our screen
Xstatic DList *screen;
X
X/*
X** initialize_lister - initialize the lister.  This is so we can
X**                     call redisplay\(\) with no arguments.
X*/
X
Xvoid initialize_lister(DList *dl) { screen = dl; }
X
X/*
X** redisplay - this routine redisplays the DList which is our screen.
X**             It assumes that the physical screen has become corrupted,
X**             clearing each line before writing to it.
X*/
X
Xstatic void redisplay()
X{
X    DLink *ln = screen->firstLine();
X    cursor_home();
X    for (int i = 0; i < rows() - 2 && ln; i++, ln = ln->next())
X    {
X        clear_to_end_of_line();
X        display_string(ln->line(), ln->length());
X    }
X    move_cursor(i, 0);
X    for (; i < rows() - 2; i++) { clear_to_end_of_line(); cursor_down(); }
X    move_to_modeline();
X    clear_to_end_of_line();
X    update_modeline();
X    clear_message_line();
X    if (screen->currLine()->length() > columns())
X        leftshift_current_line(screen);
X    else
X        move_cursor(screen->savedYPos(), screen->savedXPos());
X    synch_display();
X}
X
X/*
X** scroll_up_one_line - Scroll the listing up one line.
X**                      We only call this routine when we KNOW that
X**                      there is at least one line below the window
X**                      which can be scrolled into it and the cursor
X**                      is on the last line of the screen.
X*/
X
Xstatic void scroll_up_one_line(DList *dl)
X{
X    dl->setFirst(dl->firstLine()->next());
X    dl->setLast(dl->lastLine()->next());
X    dl->setCurrLine(dl->lastLine());
X
X    if (CS)
X    {
X        scroll_listing_up_one();
X        display_string(dl->currLine()->line(), dl->currLine()->length());
X    }
X    else if (DL || SF)
X    {
X        clear_modeline();
X        scroll_screen_up_one();
X        update_modeline();
X        move_cursor(rows()-3, 0);
X        display_string(dl->currLine()->line(), dl->currLine()->length());
X    }
X    else
X        redisplay();
X
X    dl->saveYXPos(rows()-3, goal_column(dl));
X    move_cursor(rows()-3, dl->savedXPos());
X}
X
X/*
X** scroll_down_one_line - Scroll the listing down one line.
X**                        We only call this routine when we KNOW
X**                        that the head\(\) of the listing is not visible
X**                        and the cursor is on the first line in the window.
X*/
X
Xstatic void scroll_down_one_line(DList *dl)
X{
X    if (lines_displayed(dl) == rows() - 2)
X        //
X        // Must update lastLine.  We previously had a screenfull of lines.
X        //
X        dl->setLast(dl->lastLine()->prev());
X
X    dl->setFirst(dl->firstLine()->prev());
X    dl->setCurrLine(dl->firstLine());
X
X    if (CS)
X    {
X        scroll_listing_down_one();
X        display_string(dl->currLine()->line(), dl->currLine()->length());
X    }
X    else if (AL || SR)
X    {
X        clear_modeline();
X        scroll_screen_down_one();
X        update_modeline();
X        cursor_home();
X        display_string(dl->currLine()->line(), dl->currLine()->length());
X    }
X    else
X        redisplay();
X
X    dl->saveYXPos(0, goal_column(dl));
X    move_cursor(0, dl->savedXPos());
X}
X
X/*
X** scroll_up_full_window - scroll listing up one full window,
X**                         leaving one line of overlap.  This routine
X**                         is only called when we know that the tail\(\)
X**                         of the listing is not currently displayed.
X*/
X
Xstatic void scroll_up_full_window(DList *dl)
X{
X    DLink *ln = dl->lastLine();
X    dl->setFirst(ln);
X    dl->setCurrLine(ln);
X
X    cursor_home();
X    for (int i = 0; i < rows() - 2 && ln; i++, ln = ln->next())
X    {
X        clear_to_end_of_line();
X        display_string(ln->line(), ln->length());
X    }
X    move_cursor(i, 0);
X    for (; i < rows() - 2; i++) { clear_to_end_of_line(); cursor_down(); }
X
X    ln ? dl->setLast(ln->prev()) : dl->setLast(dl->tail());
X    dl->saveYXPos(0, goal_column(dl));
X    if (dl->currLine()->length() > columns())
X        leftshift_current_line(dl);
X    else
X        move_cursor(0, dl->savedXPos());
X
X    synch_display();
X}
X
X/*
X** scroll_down_full_window - try to scroll listing down one full window,
X**                           with one line of overlap.  This routine is
X**                           only called when we KNOW that there is at
X**                           least one line "above" the current listing.
X**                           Only change the current line if it flows off
X**                           the "bottom" of the screen.  This routine is
X**                           only called when we know that the head\(\) of the
X**                           listing isn\'t currently displayed.
X*/
X
Xstatic void scroll_down_full_window(DList *dl)
X{
X    DLink *ln = dl->firstLine();
X    for (int y = 0; y < rows() - 3 && ln != dl->head(); y++, ln = ln->prev());
X    //
X    // y == # of lines preceding firstLine\(\) to add to screen
X    //
X    dl->setFirst(ln);
X    cursor_home();
X    for (int j = 0; j < rows()-2 && ln; j++, ln = ln->next())
X    {
X        clear_to_end_of_line();
X        display_string(ln->line(), ln->length());
X    }
X    move_cursor(j, 0);
X    for (; j < rows() - 2; j++) { clear_to_end_of_line(); cursor_down(); }
X
X    if (ln) dl->setLast(ln->prev());
X
X    if (dl->savedYPos()+y >= rows()-2)
X    {
X        dl->setCurrLine(dl->lastLine());
X        dl->saveYXPos(rows()-3, goal_column(dl));
X    }
X    else
X        dl->saveYXPos(dl->savedYPos()+y, dl->savedXPos());
X
X    if (dl->currLine()->length() > columns())
X        leftshift_current_line(dl);
X    else
X        move_cursor(dl->savedYPos(), dl->savedXPos());
X
X    synch_display();
X}
X
X/*
X** scroll_up_half_window - scroll listing up half a window.  This routine
X**                         is only called when the tail\(\) of the listing
X**                         isn\'t being displayed.  We try to leave the
X**                         cursor on the file it was on previously,
X**                         otherwise it is left on the first file in
X**                         the screen.
X*/
X
Xstatic void scroll_up_half_window(DList *dl, int y)
X{
X    if (dl->currLine()->length() > columns()) rightshift_current_line(dl);
X
X    DLink *ln = dl->firstLine();
X    for (int i = 0; i < (rows() - 2)/2; i++, ln = ln->next()) ;
X    dl->setFirst(ln);
X
X    if (CS || DL || SF || DLN)
X    {
X        if (CS)
X            scroll_listing_up_N((rows()-2)/2);
X        else
X        {
X            clear_modeline();
X            scroll_screen_up_N((rows()-2)/2);
X            update_modeline();
X        }
X        move_cursor(rows() - 2 -((rows()-2)/2), 0);
X        ln = dl->lastLine()->next();
X        for (i = 0; i < (rows() - 2)/2 && ln; i++, ln = ln->next())
X            display_string(ln->line(), ln->length());
X        ln ? dl->setLast(ln->prev()) : dl->setLast(dl->tail());
X    }
X    else
X    {
X
X        cursor_home();
X        for (i = 0; i < rows() - 2 && ln->next(); i++, ln = ln->next())
X        {
X            clear_to_end_of_line();
X            display_string(ln->line(), ln->length());
X        }
X
X        if (i != rows()-2)
X        {
X            //
X            // We hit last line before outputing all that we could.
X            // Must output lastLine\(\) == tail\(\).
X            //
X            display_string(ln->line(), ln->length());
X            dl->setLast(ln);
X            i++;  // so we know how many lines have been written
X        }
X        else
X            dl->setLast(ln->prev());
X
X        // now clear any remaining rows on the screen
X        move_cursor(i, 0);
X        for (; i < rows() - 2; i++) { clear_to_end_of_line(); cursor_down(); }
X    }
X
X    int pos = y - (rows()-2)/2;
X    if (pos < 0) { pos = 0; dl->setCurrLine(dl->firstLine()); }
X
X    dl->saveYXPos(pos, goal_column(dl));
X    if (dl->currLine()->length() > columns())
X        leftshift_current_line(dl);
X    else
X        move_cursor(pos, dl->savedXPos());
X
X    synch_display();
X}
X
X/*
X** scroll_down_half_window - try to scroll listing down half a window.
X**                           If `freshen\' is true, which is the default,
X**                           the screen is refreshed.  It is important
X**                           to note that we may not be able to scroll
X**                           down a complete half window, since we
X**                           always anchor the head of the listing to
X**                           the first line in the screen.  This routine
X**                           is only called when the head\(\) of the
X**                           listing isn\'t being displayed.
X*/
X
Xstatic void scroll_down_half_window(DList *dl, int y, int freshen = 1)
X{
X    if (dl->firstLine() != dl->head())
X    {
X        //
X        // We can scroll down.  Try to leave the cursor on the file
X        // it started out on.  Otherwise, leave it on the
X        // \(rows\(\)-2\)/2 line, which was the previous firstLine\(\).
X        //
X        DLink *ln = dl->firstLine();
X        for (int i = 0; i < (rows()-2)/2 && ln->prev(); i++, ln = ln->prev()) ;
X        dl->setFirst(ln);
X
X        if (dl->currLine()->length() > columns()) rightshift_current_line(dl);
X
X        if (CS || AL || ALN || SR)
X        {
X            if (CS)
X                scroll_listing_down_N(i);
X            else
X            {
X                clear_modeline();
X                scroll_screen_down_N(i);
X                update_modeline();
X                clear_message_line();
X            }
X            cursor_home();
X            for (int j = 0; j < i; j++, ln = ln->next())
X                display_string(ln->line(), ln->length());
X            ln = dl->firstLine();
X            for (int i = 0; i < rows()-2 && ln->next(); i++, ln = ln->next()) ;
X            dl->setLast(ln);
X        }
X        else
X        {
X            cursor_home();
X            for (int i = 0; i < rows()-2 && ln->next(); i++, ln = ln->next())
X            {
X                clear_to_end_of_line();
X                display_string(ln->line(), ln->length());
X            }
X
X            if (i != rows() - 2)
X            {
X                //
X                // We hit last line before outputing all that we could.
X                // Must output lastLine\(\) == tail\(\).
X                //
X                display_string(ln->line(), ln->length());
X                dl->setLast(ln);
X                i++;  // so we know how many lines have been written
X            }
X            else
X                dl->setLast(ln->prev());
X
X            // now clear any remaining rows on the screen
X            int tmp = i;
X            for (; i < rows()-2; i++) { clear_to_end_of_line();cursor_down(); }
X            i = tmp;  // because we use `i\' below
X        }
X
X        int pos = i + y;
X        if (pos > rows() - 3)
X        {
X            pos = rows() - 3;
X            dl->setCurrLine(dl->lastLine());
X        }
X
X        dl->saveYXPos(pos, goal_column(dl));
X        if (dl->currLine()->length() > columns())
X            leftshift_current_line(dl);
X        else
X            move_cursor(pos, dl->savedXPos());
X
X        if (freshen) synch_display();
X    }
X}
X
X/*
X** goto_first - position cursor on first line in listing.  This routine
X**              is not called if atBegOfList\(\) is true.
X*/
X
Xstatic void goto_first(DList *dl)
X{
X    if (dl->head() != dl->firstLine())
X        initial_listing(dl);
X    else
X    {
X        if (dl->currLine()->length() > columns()) rightshift_current_line(dl);
X        dl->setCurrLine(dl->head());
X    }
X
X    dl->saveYXPos(0, goal_column(dl));
X    if (dl->currLine()->length() > columns())
X        leftshift_current_line(dl);
X    else
X        move_cursor(0, dl->savedXPos());
X
X    synch_display();
X}
X
X/*
X** goto_last - position cursor on last file in listing.  This routine is
X**             not called if atEndOfList\(\) is true.
X*/
X
Xstatic void goto_last(DList *dl)
X{
X    if (dl->currLine()->length() > columns()) rightshift_current_line(dl);
X
X    dl->setCurrLine(dl->tail());
X
X    if (dl->tail() == dl->lastLine())
X    {
X        //
X        // Only need to reposition the cursor.
X        //
X        dl->saveYXPos(lines_displayed(dl) - 1, goal_column(dl));
X        if (dl->currLine()->length() > columns())
X            leftshift_current_line(dl);
X        else
X            move_cursor(dl->savedYPos(), dl->savedXPos());
X    }
X    else
X    {
X        //
X        // Redisplay end of listing & update our view.
X        //
X        DLink *ln = dl->tail();
X        dl->setLast(ln);
X        for (int i = 0; i < rows() - 2; i++, ln = ln->prev())
X        {
X            move_cursor(rows() - 3 - i, 0);
X            clear_to_end_of_line();
X            display_string(ln->line(), ln->length());
X        }
X        dl->setFirst(ln->next());
X        dl->saveYXPos(rows() - 3,goal_column(dl));
X        if (dl->currLine()->length() > columns())
X            leftshift_current_line(dl);
X        else
X            move_cursor(rows() -3 , dl->savedXPos());
X    }
X    synch_display();
X}
X
X
X/*
X** type_any_key_to_continue - ask user to type any key to continue.
X**                            Done in standout mode.
X*/
X
Xstatic inline void type_any_key_to_continue()
X{
X    eat_a_character("Press Any Key to Continue", redisplay, 1);
X}
X
X/*
X** examine_current_problem - attempt to examine the current problem.
X*/
X
Xstatic void examine_current_problem(const DList *dl)
X{
X    char *number = get_prob_number(dl);
X    if (examine_problem(number))
X        redisplay();
X    else
X    {
X        move_cursor(dl->savedYPos(), dl->savedXPos());
X        synch_display();
X    }
X}
X
X/*
X** update_problem_listing - updates the current line in the listing.
X**                          `number\' is the number of the problem
X**                          in the current line.
X*/
X
Xstatic void update_problem_listing(DList *dl, const char *number)
X{
X    datum key;
X    key.dptr  = (char *) number;
X    key.dsize = (int)strlen(key.dptr) + 1;
X    open_database(GDBM_READER);
X    datum data = gdbm_fetch(GdbmFile, key);
X    gdbm_close(GdbmFile);
X    if (data.dptr)
X    {
X        char *newline = summary_info(data);
X        dl->currLine()->update(&newline);
X        free(data.dptr);
X    }
X}
X
X/*
X** append_current_problem - attempt to append to the current problem.
X**                          If successful, updates the listing line.
X*/
X
Xstatic void append_current_problem(DList *dl)
X{
X    char *number = get_prob_number(dl);
X    if (append_to_problem(number))
X    {
X        //
X        // Replace old listing line with new.
X        //
X        update_problem_listing(dl, number);
X        redisplay();
X    }
X    else
X    {
X        move_cursor(dl->savedYPos(), dl->savedXPos());
X        synch_display();
X    }
X}
X
X/*
X** close_current_problem - attempt to close the current problem
X*/
X
Xstatic void close_current_problem(DList *dl)
X{
X    char *number = get_prob_number(dl);
X    if (close_problem(number))
X    {
X        //
X        // Replace old listing line with new.
X        //
X        update_problem_listing(dl, number);
X        redisplay();
X    }
X    else
X    {
X        move_cursor(dl->savedYPos(), dl->savedXPos());
X        synch_display();
X    }
X}
X
X/*
X** reopen_current_problem - attempt to reopen the current problem
X*/
X
Xstatic void reopen_current_problem(DList *dl)
X{
X    char *number = get_prob_number(dl);
X    if (reopen_problem(number))
X    {
X        //
X        // Replace old listing line with new.
X        //
X        update_problem_listing(dl, number);
X        redisplay();
X    }
X    else
X    {
X        move_cursor(dl->savedYPos(), dl->savedXPos());
X        synch_display();
X    }
X}
X
X/*
X** modify_current_keywords - attempt to modify the keywords of the
X**                           current problem
X*/
X
Xstatic void modify_current_keywords(DList *dl)
X{
X    char *number = get_prob_number(dl);
X    if (modify_keywords(number))
X    {
X        //
X        // Replace old listing line with new.
X        //
X        update_problem_listing(dl, number);
X        redisplay();
X    }
X    else
X    {
X        move_cursor(dl->savedYPos(), dl->savedXPos());
X        synch_display();
X    }
X}
X
X/*
X** remove_listing_line - delete the current line in the DList
X**                       and update both the screen and data
X**                       structures appropriately.  `y\' is the position
X**                       in the window of the current line.  Returns 0
X**                       if we\'ve removed the last line in the listing,
X**                       otherwise returns 1.
X*/
X
Xstatic int remove_listing_line(DList *dl, int y)
X{
X    if (dl->lastLine() != dl->tail())
X    {
X        //
X        // Last line in listing isn\'t in window - scroll up one line.
X        //
X        dl->setLast(dl->lastLine()->next());
X        dl->deleteLine();
X
X        if (CS || DL)
X        {
X            if (CS)
X                delete_listing_line(y);
X            else
X            {
X                clear_modeline();
X                delete_screen_line(y);
X                update_modeline();
X            }
X            move_cursor(rows()-3, 0);
X            display_string(dl->lastLine()->line(), dl->lastLine()->length());
X        }
X        else
X        {
X            clear_to_end_of_screen(y);
X            move_cursor(y, 0);
X            DLink *ln = dl->currLine();
X            for (int i = y; i < rows()-2; i++, ln = ln->next())
X                display_string(ln->line(), ln->length());
X            update_modeline();
X        }
X        dl->saveYXPos(y, goal_column(dl));
X    } else
X    {
X        //
X        // Last line of listing is visible in window.
X        //
X        if (dl->atWindowTop() && dl->atWindowBot())
X        {
X            //
X            // The last line in the window is also the first line.
X            //
X            if (dl->nelems() == 1)
X            {
X                cursor_home();
X                clear_to_end_of_line();
X                return 0;
X            }
X            scroll_down_half_window(dl, y, 0);
X            dl->deleteLine();
X            DLink *ln = dl->firstLine();
X            for (int pos = 0; ln != dl->tail(); pos++, ln = ln->next()) ;
X            dl->saveYXPos(pos, goal_column(dl));
X            move_cursor(pos+1, 0);
X            clear_to_end_of_line();
X            move_cursor(pos, dl->savedXPos());
X        }
X        else if (dl->atWindowBot())
X        {
X            //
X            // We want to delete the last line in the window.
X            //
X            dl->deleteLine();
X            move_cursor(y, 0);
X            clear_to_end_of_line();
X            dl->saveYXPos(y-1, goal_column(dl));
X            move_cursor(y-1, dl->savedXPos());
X        }
X        else
X        {
X            //
X            // We are in the middle of the listing.
X            //
X            dl->deleteLine();
X            if (CS || DL)
X            {
X                if (CS)
X                    delete_listing_line(y);
X                else
X                {
X                    clear_modeline();
X                    delete_screen_line(y);
X                    update_modeline();
X                }
X            } else
X            {
X                clear_to_end_of_screen(y);
X                move_cursor(y, 0);
X                for (DLink *ln = dl->currLine(); ln; ln = ln->next())
X                    display_string(ln->line(), ln->length());
X                update_modeline();
X            }
X            dl->saveYXPos(y, goal_column(dl));
X         }
X    }
X    if (dl->currLine()->length() > columns())
X        leftshift_current_line(dl);
X    else
X        move_cursor(dl->savedYPos(), dl->savedXPos());
X    return 1;
X}
X
X/*
X** delete_current_problem - attempt to delete the current problem.  Returns
X**                          0 if there are no more problems to view.
X*/
X
Xstatic int delete_current_problem(DList *dl)
X{
X    char *number = get_prob_number(dl);
X
X    if (delete_problem(number))
X        if (remove_listing_line(dl, dl->savedYPos()) == 0)
X            return 0;
X
X    move_cursor(dl->savedYPos(), dl->savedXPos());
X    synch_display();
X    return 1;
X}
X
X/*
X** save_problem_listing - saves problem listing to a file of the users choice.
X**                        If the first character of the filename is `~\', the
X**                        tilde is replaced by the users home directory.
X*/
X
Xstatic void save_problem_listing(const DList *dl)
X{
X    message_window_dirty = 1; // force message window dirty
X    int status;
X    char *file = prompt("Filename --> ", redisplay);
X    const char *fullname;
X    fullname = *file == '~' ? expand_tilde(file) : file;
X    pid_t pid = fork();
X    switch(pid)
X    {
X      case -1: // error
X        message("Sorry, can't write, fork() failed");
X        break;
X      case 0:  // in the child
X        if (setuid(getuid()) < 0)
X            exit(1);
X        else
X        {
X            FILE *fp = fopen(fullname, "w");
X            if (!fp)
X                exit(1);
X            else
X            {
X                // try to write the file
X                for (DLink *ln = dl->head(); ln; ln = ln->next())
X                    (void)fprintf(fp, "%s\n", ln->line());
X                if (ferror(fp)) exit(1);
X            }
X            (void)fclose(fp);
X        }
X        exit(0);
X      default: // in the parent
X        waitpid(pid, &status, 0);
X        if (!status)
X            message("listing saved to file `%'", fullname);
X        else
X            message("problem saving listing, sorry");
X        DELETE file;
X        break;
X    }
X    move_cursor(dl->savedYPos(), dl->savedXPos());
X    synch_display();
X}
X
X/*
X** help - give some help.  Deal with SIGWINCH and SIGTSTP.
X*/
X
Xstatic void help()
X{
X    String old_modeline(current_modeline);
X    update_modeline("----- HELP");
X
X    int position = 0;
X    char key;
X    do {
X        cursor_home();
X        for (int i = 0; i < rows() - 2 && i + position < HELP_FILE_DIM; i++)
X        {
X            clear_to_end_of_line();
X            display_string(help_file[position + i]);
X        }
X        move_cursor(i, 0);
X        for (; i < rows() - 2; i++) { clear_to_end_of_line(); cursor_down(); }
X        clear_message_line();
X
X        if (position + rows() -2 >= HELP_FILE_DIM)
X            // the tail of the help message
X            (void)fputs(HELP_MSG[2], stdout);
X        else if (position == 0)
X            // the head of the help message
X            (void)fputs(HELP_MSG[0], stdout);
X        else
X            //  somewhere in between
X            (void)fputs(HELP_MSG[1], stdout);
X        synch_display();
X
X        if (resumingAfterSuspension ||
X#ifdef SIGWINCH
X            windowSizeChanged       ||
X#endif
X            read(0, &key, 1) < 0 // assume fails only when errno == EINTR
X            )
X        {
X#ifdef SIGWINCH
X            if (windowSizeChanged) { windowSizeChanged = 0; adjust_window(); }
X#endif
X            resumingAfterSuspension = 0;
X            redisplay();
X        }
X        else if (key == KEY_SPC)
X        {
X            if (position >= HELP_FILE_DIM - 1) break;
X            position += rows() - 2;
X        }
X        else if (key == *BC)
X        {
X            if (position == 0) break;
X            position -= rows() - 2;
X        }
X        else
X            break;  // return to the listing
X    }
X    while (position < HELP_FILE_DIM - 1);
X
X    update_modeline(old_modeline);
X    redisplay();
X}
X
X/*
X** shell_command - execute a shell command.
X**                 If *cmd == \'\0\', start up a shell.
X**                 If *cmd == \'!\', reexecute most recent shell command.
X*/
X
Xstatic void shell_command(DList *dl)
X{
X    static String saved_cmd;
X    static String saved_shell;
X    const char *separators   = " \t";     // separators for tokenize\(\)
X    const char *cmd  = prompt("!", redisplay);
X
X    if (cmd == 0)
X        return;  // aborted
X    else if (*cmd == 0)
X    {
X        //
X        // Start up a shell.
X        //
X        if (saved_shell == "") saved_shell = getenv("SHELL");
X        if (saved_shell == "") saved_shell = "sh";
X        saved_cmd = saved_shell;
X
X        const char *slash = strrchr(saved_shell, '/');
X        const char *args[2];
X        args[0] = slash ? slash + 1 : (const char *)saved_shell;
X        args[1] = 0;
X
X        message("Starting interactive shell ...");
X        cursor_wrap();
X        synch_display();
X        execute(saved_shell, args);
X    }
X    else if (*cmd == '!')
X    {
X        //
X        //  Re-execute previously saved command.
X        //
X        if (saved_cmd != "")
X        {
X            message(saved_cmd);
X            cursor_wrap();
X            synch_display();
X            const char **args = tokenize(saved_cmd, separators);
X            execute(args[0], args);
X            type_any_key_to_continue();
X        }
X        else
X        {
X            ding();
X            message("No previous shell command");
X            move_cursor(dl->savedYPos(), dl->savedXPos());
X            synch_display();
X            return;
X        }
X    } else
X    {
X        //
X        // Execute command.
X        //
X        saved_cmd = cmd;
X        message(saved_cmd);
X        cursor_wrap();
X        synch_display();
X        const char **args = tokenize(saved_cmd, separators);
X        execute(args[0], args);
X        type_any_key_to_continue();
X    }
X    redisplay();
X}
X
X/*
X** read_from_keybd - read a key from the keyboard, taking care
X**                   of SIGTSTPs and SIGWINCHs.  If the read\(\) fails,
X**                   we assume it\'s because we caught a SIGTSTP
X**                   or SIGWINCH.  In that case we redraw the screen
X**                   with redisplay\(\).
X*/
X
Xstatic char read_from_keybd()
X{
X    char key;
X    while (1)
X    {
X        if (resumingAfterSuspension ||
X#ifdef SIGWINCH
X            windowSizeChanged       ||
X#endif
X            read(0, &key, 1) < 0)  // assume only fails when errno==EINTR
X        {
X#ifdef SIGWINCH
X            if (windowSizeChanged)
X            {
X                windowSizeChanged = 0;
X                adjust_window();
X            }
X#endif
X            resumingAfterSuspension = 0;
X            redisplay();
X            continue;
X        }
X        return key;
X    }
X}
X
X/*
X** get_key - reads a key and then clears the message window,
X**           if it needs to be cleared. Used only by read_commands in the
X**           main switch statement so that message\(\) doesn\'t need to sleep\(\)
X**           and clear\(\) on the messages that get written.  This way, the
X**           message window is cleared after each keypress within the main
X**           loop, when necessary.  We also check for and deal with window
X**           size changes and the UP and DOWN arrow keys here.
X*/
X
Xstruct arrow_key {
X    int len;
X    int *seq;
X    arrow_key(const char *);
X};
X
Xarrow_key::arrow_key(const char *str)
X{
X    if (str == 0)
X    {
X        //
X        // The capability isn\'t defined.
X        //
X        len = 0;
X        seq = 0;
X        return;
X    }
X
X    seq = new int[12]; // should be ample
X
X    int i = 0;
X    do
X    {
X        switch (*str)
X        {
X          case '\\':
X          {
X              int c = *++str;
X              switch (c)
X              {
X                case 'E':  seq[i++] = 0x1b; break;
X                case 'b':  seq[i++] = '\b'; break;
X                case 'f':  seq[i++] = '\f'; break;
X                case 'n':  seq[i++] = '\n'; break;
X                case 'r':  seq[i++] = '\r'; break;
X                case 't':  seq[i++] = '\t'; break;
X                case 'v':  seq[i++] = '\v'; break;
X                case '\\': seq[i++] = '\\'; break;
X                case '\'': seq[i++] = '\''; break;
X                case '\"': seq[i++] = '\"'; break;
X                case '^':  seq[i++] = '^';  break;
X                default:
X                    error("invalid escape in /etc/termcap for arrow key: \\%c", c);
X                    break;
X              }
X              break;
X          }
X          case '^':
X          {
X              int c = *++str;
X              if (isalpha(c))
X              {
X                  seq[i] = (c > 'a' ? c - 'a' : c - 'A') + 1;
X                  i++;  // g++ 2.2.2 chokes if I write seq\[i++\] = ...
X              }
X              else
X                  switch(c)
X                  {
X                    case '[':  seq[i++] = 0x1b; break;
X                    case '\\': seq[i++] = 0x1c; break;
X                    case ']':  seq[i++] = 0x1d; break;
X                    case '^':  seq[i++] = 0x1e; break;
X                    case '_':  seq[i++] = 0x1f; break;
X                    default:
X                        error("invalid control sequence for arrow key: ^%c", c);
X                        break;
X                  }
X              }
X              break;
X          default: seq[i++] = *str; break;
X        }
X    } while (*++str);
X    len = i;
X}
X
Xstatic char get_key(DList *dl)
X{
X    int index = 0;
X    char key;
X    static arrow_key up(KU), down(KD);
X    static char *keys;
X    static int remaining = 0;
X
X    if (!keys) keys = new char[max(up.len, down.len)];
X
X    if (remaining)
X    {
X        //
X        // We have some characters left over from a partial match
X        // of an arrow key; use them up.
X        //
X        key = keys[0];
X        remaining--;
X        for (int i = 0; i < remaining; i++) keys[i] = keys[i+1];
X        return key;
X    }
X    else
X        key = read_from_keybd();
X
X    if (message_window_dirty)
X    {
X        clear_message_line();
X        move_cursor(dl->savedYPos(), dl->savedXPos());
X        synch_display();
X        message_window_dirty = 0;
X    }
X
X    //
X    // Now deal with potential arrow keys.
X    //
X    if (KU || KD)
X    {
X        for (index = 0; (index < up.len && up.seq[index] == key) ||
X             (index < down.len && down.seq[index] == key); index++)
X        {
X            if ((up.len - 1) == index && up.seq[index] == key)
X                return KEY_ARROW_UP;
X            if ((down.len - 1) == index && down.seq[index] == key)
X                return KEY_ARROW_DOWN;
X            if (index == (max(up.len, down.len) - 1)) break;
X            keys[index] = key;
X            key = read_from_keybd();
X        }
X        if (index == 0)
X            return key; // no initial match -- the most usual case
X        else
X        {
X            //
X            // We had a partial match, but not a complete one.
X            // We must return the characters which we\'ve read in
X            // the proper order so that the main command loop can
X            // check for matches.  The problem here is the potential
X            // ambiguity between what the terminal claims to be arrow
X            // keys and what has been hardcoded as commands.
X            //
X            keys[index] = key;
X            key = keys[0];  // what we\'ll return to the command loop
X            for (int i = 0; i < index; i++) keys[i] = keys[i+1];
X            remaining = index;
X            return key;
X        }
X    }
X    else
X        return key;
X}
X
X/*
X** read_commands - the command loop
X*/
X
Xvoid lister_cmd_loop(DList *dl)
X{
X    int key;
X    for (;;)
X    {
X        switch (key = get_key(dl))
X        {
X          case KEY_j:
X          case KEY_n:
X          case KEY_CTL_N:
X          case KEY_SPC:
X          case KEY_CR:
X          case KEY_ARROW_DOWN:
X            if (dl->atEndOfList())
X            {
X                ding();
X                break;
X            }
X            if (dl->currLine()->length() > columns())
X                rightshift_current_line(dl);
X            if (dl->savedYPos() < rows() - 3)
X            {
X                // There are still more lines below us in the window
X                // so we just move the cursor down one line.
X                dl->setCurrLine(dl->currLine()->next());
X                int x = goal_column(dl);
X                if (x == dl->savedXPos())
X                    cursor_down();
X                else
X                    move_cursor(dl->savedYPos() + 1, x);
X                dl->saveYXPos(dl->savedYPos() + 1, x);
X            }
X            else
X                //
X                // We are on the last line on the screen and there
X                // are more lines to display.  Scroll up one line
X                // and leave the cursor on the next logical line.
X                //
X                scroll_up_one_line(dl);
X            if (dl->currLine()->length() > columns())
X                leftshift_current_line(dl);
X            synch_display();
X            break;
X
X          case KEY_k:
X          case KEY_p:
X          case KEY_CTL_P:
X          case KEY_CTL_Y:
X          case KEY_ARROW_UP:
X            if (dl->atBegOfList())
X            {
X                ding();
X                break;
X            }
X            if (dl->currLine()->length() > columns())
X                rightshift_current_line(dl);
X            if (dl->savedYPos() != 0)
X            {
X                // We aren\'t at the top of the window so can move up.
X                dl->setCurrLine(dl->currLine()->prev());
X                int x = goal_column(dl);
X                if (x == dl->savedXPos() && UP)
X                    cursor_up();
X                else
X                    move_cursor(dl->savedYPos() - 1, x);
X                dl->saveYXPos(dl->savedYPos() - 1, x);
X            }
X           else
X               //
X               // We are on the first line of the window and there are
X               // lines preceding us in the directory listing.
X               //
X               scroll_down_one_line(dl);
X            if (dl->currLine()->length() > columns())
X                leftshift_current_line(dl);
X            synch_display();
X            break;
X
X          case KEY_CTL_F:
X          case KEY_CTL_V:
X            if (dl->lastLine() == dl->tail())
X            {
X                ding();
X                break;
X            }
X            scroll_up_full_window(dl);
X            break;
X
X          case KEY_b:
X          case KEY_CTL_B:
X            if (dl->firstLine() == dl->head())
X            {
X                ding();
X                break;
X            }
X            scroll_down_full_window(dl);
X            break;
X
X          case KEY_CTL_D:
X            if (dl->lastLine() == dl->tail())
X            {
X                ding();
X                break;
X            }
X            scroll_up_half_window(dl, dl->savedYPos());
X            break;
X
X          case KEY_CTL_U:
X            if (dl->firstLine() == dl->head())
X            {
X                ding();
X                break;
X            }
X            scroll_down_half_window(dl, dl->savedYPos());
X            break;
X
X          case KEY_TOP:
X            if (dl->atBegOfList())
X            {
X                ding();
X                break;
X            }
X            goto_first(dl);
X            break;
X
X          case KEY_BOT:
X            if (dl->atEndOfList())
X            {
X                ding();
X                break;
X            }
X            goto_last(dl);
X            break;
X
X          case KEY_e:
X          case KEY_m:
X          case KEY_v:
X            examine_current_problem(dl); break;
X
X          case KEY_a:
X            append_current_problem(dl); break;
X
X          case KEY_c:
X            close_current_problem(dl); break;
X
X          case KEY_d:
X            if (delete_current_problem(dl) == 0)
X                //
X                // No more problems to view.
X                //
X                return;
X            break;
X
X          case KEY_r:
X            reorganize_database(0);
X            move_cursor(dl->savedYPos(), dl->savedXPos());
X            synch_display();
X            break;
X
X          case KEY_M:
X            modify_current_keywords(dl); break;
X
X          case KEY_R:
X            reopen_current_problem(dl); break;
X
X          case KEY_S:
X            save_problem_listing(dl); break;
X
X          case KEY_QM: case KEY_H:
X            help(); break;
X
X          case KEY_BANG:
X            shell_command(dl); break;
X
X          case KEY_V:
X            message(Version);
X            move_cursor(dl->savedYPos(), dl->savedXPos());
X            synch_display();
X            break;
X
X          case KEY_CTL_L:
X            redisplay(); break;
X
X          case KEY_q:
X            return;
X
X          case KEY_ESC:
X            //
X            // Some Emacs ESC key bindings.
X            //
X            switch(get_key(dl))
X            {
X              case KEY_v:
X                if (dl->firstLine() == dl->head())
X                {
X                    ding();
X                    break;
X                }
X                scroll_down_full_window(dl);
X                break;
X
X              case KEY_TOP:
X                if (dl->atBegOfList())
X                {
X                    ding();
X                    break;
X                }
X                goto_first(dl);
X                break;
X
X              case KEY_BOT:
X                if (dl->atEndOfList())
X                {
X                    ding();
X                    break;
X                }
X                goto_last(dl);
X                break;
X
X              default:
X                ding();
X                break;
X            }
X            break;
X
X          default: ding(); break;
X        }
X    }
X}
END_OF_FILE
if test 38236 -ne `wc -c <'lister.C'`; then
    echo shar: \"'lister.C'\" unpacked with wrong size!
fi
# end of 'lister.C'
fi
echo shar: End of archive 4 \(of 7\).
cp /dev/null ark4isdone
MISSING=""
for I in 1 2 3 4 5 6 7 ; do
    if test ! -f ark${I}isdone ; then
    MISSING="${MISSING} ${I}"
    fi
done
if test "${MISSING}" = "" ; then
    echo You have unpacked all 7 archives.
    rm -f ark[1-9]isdone
else
    echo You still need to unpack the following archives:
    echo "        " ${MISSING}
fi
##  End of shell archive.
exit 0

exit 0 # Just in case...