tostring
rlxstr = (uschar *) tostring((char *) buf);
f->restr = (uschar *) tostring(s);
char *cp = tostring(buf);
s = tostring(buf);
yylval.s = tostring(buf);
fldtab[i]->sval = tostring(buf);
fldtab[0]->nval = tostring("0");
fldtab[i]->nval = tostring(temp);
extern char *tostring(const char *);
buf = tostring(s);
fmt = tostring("%a %b %d %H:%M:%S %Z %Y");
fmt = tostring(getsval(x));
files[0].fname = tostring("/dev/stdin");
files[1].fname = tostring("/dev/stdout");
files[2].fname = tostring("/dev/stderr");
files[i].fname = tostring(s);
repl = tostring(getsval(x));
y->sval = tostring(x->sval);
p->nval = tostring(n);
p->sval = s ? tostring(s) : tostring("");
t = s ? tostring(s) : tostring(""); /* in case it's self-assign */