BSD 1 development

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

#include "ex.h"
#include "ex_re.h"
/*
* Ex - a text editor
* Bill Joy UCB June, 1977
*/
static  char bigmove;

setdot()
{

       setdot1();
       if (bigmove)
               markDOT();
}

setdot1()
{

       if (addr2 == 0)
               addr1 = addr2 = dot;
       if (addr1 > addr2) {
               notempty();
               error("Addr1 > addr2|First address exceeds second");
       }
}

setcount()
{
       register int cnt;

       skipwh();
       if (!digit(peekchar())) {
               setdot();
               return;
       }
       addr1 = addr2;
       setdot();
       cnt = getnum();
       if (cnt <= 0)
               error("Bad count|Nonzero count required");
       addr2 =+ cnt - 1;
       if (addr2 > dol)
               addr2 = dol;
       nonzero();
}

getnum()
{
       register int cnt;

       for (cnt = 0; digit(peekchar());)
               cnt = cnt * 10 + getchar() - '0';
       return (cnt);
}
markDOT()
{

       markpr(dot);
}

markpr(dot)
       int *dot;
{

       if ((inglobal == 0 || inopen) && dot <= endcore)
               names[26] = *dot & ~01;
}

notempty()
{

       if (dol == zero)
               error("No lines@in the buffer");
}

setall()
{

       if (addr2 == 0) {
               addr1 = one;
               addr2 = dol;
               if (dol == zero) {
                       dot = zero;
                       return;
               }
       }
       setdot1();
}

setnoaddr()
{

       if (addr2 != 0)
               error("No address allowed@on this command");
}

nonzero()
{

       if (addr1 == zero) {
               notempty();
               error("Nonzero address required@on this command");
       }
}

int *
address()
{
       register int *addr, offset;
       register c;
       int lastsign;

       bigmove = 0;
       lastsign = 0;
       offset = 0;
       addr = 0;
       for (;;) {
               if (digit(peekchar())) {
                       if (addr == 0) {
                               addr = zero;
                               bigmove = 1;
                       }
                       addr =+ offset;
                       offset = getnum();
                       if (lastsign >= 0)
                               addr =+ offset;
                       else
                               addr =- offset;
                       lastsign = 0;
                       offset = 0;
               }
               switch (c = getchar()) {

               case '?':
               case '/':
               case '$':
               case '\'':
               case '\\':
                       bigmove++;
               case '.':
                       if (addr || offset)
                               error("Relocation error@- can only offset by constants");
               }
               offset =+ lastsign;
               lastsign = 0;
               switch (c) {

               case ' ':
               case '\t':
                       continue;

               case '+':
                       lastsign = 1;
                       if (addr == 0)
                               addr = dot;
                       continue;

               case '^':
               case '-':
                       lastsign = -1;
                       if (addr == 0)
                               addr = dot;
                       continue;

               case '\\':
               case '?':
               case '/':
                       c = compile(c, 1);
                       if (c == '&') {
                               c = getchar();
                               if (c != '?' && c != '/')
                                       error("\\& needs / or ? in address");
                       }
                       notempty();
                       addr = scanfor(c);
                       if (addr == NIL)
                               error("Fail|Pattern not found");
                       continue;

               case '$':
                       addr = dol;
                       continue;

               case '.':
                       addr = dot;
                       continue;

               case '\'':
                       c = getchar();
                       if (c == '\'')
                               c = 'z' + 1;
                       else if (c < 'a' || c > 'z')
                               error("Marks are ' and a-z");
                       c =- 'a';
                       for (addr = one; addr <= dol; addr++)
                               if (names[c] == (*addr &~ 01))
                                       break;
                       if (addr > dol)
                               error("Undefined mark@referenced");
                       break;

               default:
                       ungetchar(c);
                       if (offset) {
                               if (addr == 0)
                                       addr = dot;
                               addr =+ offset;
                       }
                       if (addr == 0) {
                               bigmove = 0;
                               return (0);
                       }
                       if (addr != zero)
                               notempty();
                       addr =+ lastsign;
                       if (addr < zero)
                               error("Negative address@- first buffer line is 1");
                       if (addr > dol)
                               error("Not that many lines@in buffer");
                       return (addr);
               }
       }
}

scanfor(c)
       char c;
{
       register int *addr;

       savere(&scanre);
       addr = dot;
       for (;;) {
               if (c == '/') {
                       addr++;
                       if (addr > dol) {
                               if (value(WRAP) == 0)
                                       error("No match to BOTTOM|Address search hit BOTTOM without matching pattern");
                               addr = zero;
                       }
               } else {
                       addr--;
                       if (addr < zero) {
                               if (value(WRAP) == 0)
                                       error("No match to TOP|Address search hit TOP without matching pattern");
                               addr = dol;
                       }
               }
               if (execute(0, addr))
                       return (addr);
               if (addr == dot)
                       return (NIL);
       }
}