BSD 1 development

[unix-history] / ex-1.1 / exm.c

#include "ex.h"
/*
* Ex - a text editor
* Bill Joy UCB June/August 1977
*/

int     getcopy();

move()
{
       register int *adt;

       if (Command[0] == 'M') {
               setdot1();
               markpr(addr2 == dot ? addr1 - 1 : addr2 + 1);
       } else
               setdot();
       nonzero();
       adt = address();
       if (adt == 0)
               error("%s where?|%s requires a trailing address", Command);
       newline();
       move1(Command[0] != 'M', adt);
       killed();
}

int     *tad1;

move1(cflag, addrt)
       char cflag;
       int *addrt;
{
       register int *adt, *ad1, *ad2;
       int lines;

       adt = addrt;
       lines = (addr2 - addr1) + 1;
       if (cflag) {
               tad1 = addr1;
               ad1 = dol;
               append(getcopy, ad1++);
               ad2 = dol;
       } else {
               ad2 = addr2;
               for (ad1 = addr1; ad1 <= ad2;)
                       *ad1++ =& ~01;
               ad1 = addr1;
       }
       ad2++;
       if (adt < ad1) {
               if (adt + 1 == ad1 && !cflag)
                       error("That move would do nothing!");
               dot = adt + (ad2 - ad1);
               if (++adt != ad1) {
                       reverse(adt, ad1);
                       reverse(ad1, ad2);
                       reverse(adt, ad2);
               }
       } else if (adt >= ad2) {
               dot = adt++;
               reverse(ad1, ad2);
               reverse(ad2, adt);
               reverse(ad1, adt);
       } else
               error("Move to a moved line");
       change();
       if (!inglobal)
               if (cflag) {
                       undap1 = addrt + 1;
                       undap2 = undap1 + lines;
                       deletenone();
               } else {
                       undkind = UNDMOVE;
                       undap1 = addr1;
                       undap2 = addr2;
                       unddel = addrt;
                       unddol = dol;
               }
}

reverse(a1, a2)
       register int *a1, *a2;
{
       register int t;

       for (;;) {
               t = *--a2;
               if (a2 <= a1)
                       return;
               *a2 = *a1;
               *a1++ = t;
       }
}

getcopy()
{
       if (tad1 > addr2)
               return (EOF);
       getline(*tad1++);
       return (0);
}

getPUT()
{
       if (tad1 > unddol)
               return (EOF);
       getline(*tad1++);
       tad1++;
       return (0);
}

yank()
{

       save12();
       undkind = UNDNONE;
       killed();
}

PUT()
{
       register int cnt;

       cnt = unddol - dol;
       tad1 = dol + 1;
       append(getPUT, addr2);
       netchange(cnt);
}