/*
* Parse a number out of the command input stream.
*/
getnum()
{
register int cnt;
for (cnt = 0; isdigit(peekcd());)
cnt = cnt * 10 + ex_getchar() - '0';
return (cnt);
}
/*
* Parse an address.
* Just about any sequence of address characters is legal.
*
* If you are tricky you can use this routine and the = command
* to do simple addition and subtraction of cardinals less
* than the number of lines in the file.
*/
line *
address(char *inputline)
{
register line *addr;
register int offset, c;
short lastsign;
bigmove = 0;
lastsign = 0;
offset = 0;
addr = 0;
for (;;) {
if (isdigit(peekcd())) {
if (addr == 0) {
addr = zero;
bigmove = 1;
}
loc1 = 0;
addr += offset;
offset = getnum();
if (lastsign >= 0)
addr += offset;
else
addr -= offset;
lastsign = 0;
offset = 0;
}
switch (c = getcd()) {
case '?':
case '/':
case '$':
case '\'':
case '\\':
bigmove++;
case '.':
if (addr || offset)
error("Badly formed address");
}
offset += lastsign;
lastsign = 0;
switch (c) {
case ' ':
case '\t':
continue;
case '+':
lastsign = 1;
if (addr == 0)
addr = dot;
continue;
case '^':
case '-':
lastsign = -1;
if (addr == 0)
addr = dot;
continue;
case '\\':
case '?':
case '/':
c = compile(c, 1);
notempty();
savere(scanre);
addr = dot;
if (inputline && execute(0, dot)) {
if (c == '/') {
while (loc1 <= inputline) {
if (loc1 == loc2)
loc2++;
if (!execute(1, NULL))
goto nope;
}
break;
} else if (loc1 < inputline) {
char *last;
doques:
do {
last = loc1;
if (loc1 == loc2)
loc2++;
if (!execute(1, NULL))
break;
} while (loc1 < inputline);
loc1 = last;
break;
}
}
nope:
for (;;) {
if (c == '/') {
addr++;
if (addr > dol) {
if (value(WRAPSCAN) == 0)
error("No match to BOTTOM|Address search hit BOTTOM without matching pattern");
addr = zero;
}
} else {
addr--;
if (addr < zero) {
if (value(WRAPSCAN) == 0)
error("No match to TOP|Address search hit TOP without matching pattern");
addr = dol;
}
}
if (execute(0, addr)) {
if (inputline && c == '?') {
inputline = &linebuf[LBSIZE];
goto doques;
}
break;
}
if (addr == dot)
error("Fail|Pattern not found");
}
continue;
case '$':
addr = dol;
continue;
case '.':
addr = dot;
continue;
case '\'':
c = markreg(ex_getchar());
if (c == 0)
error("Marks are ' and a-z");
addr = getmark(c);
if (addr == 0)
error("Undefined mark@referenced");
break;
default:
ungetchar(c);
if (offset) {
if (addr == 0)
addr = dot;
addr += offset;
loc1 = 0;
}
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);
}
}
}
