/* Parse and evaluate match (regex) expressions */
struct val *
eval5(void)
{
regex_t rp;
regmatch_t rm[2];
char errbuf[256];
int eval;
struct val *l, *r;
struct val *v;
l = eval6();
while (token == MATCH) {
nexttoken(1);
r = eval6();
/* coerce to both arguments to strings */
to_string(l);
to_string(r);
/* compile regular expression */
if ((eval = regcomp(&rp, r->u.s, 0)) != 0) {
regerror(eval, &rp, errbuf, sizeof(errbuf));
errx(2, "%s", errbuf);
}
/* compare string against pattern -- remember that patterns
are anchored to the beginning of the line */
if (regexec(&rp, l->u.s, 2, rm, 0) == 0 && rm[0].rm_so == 0) {
if (rm[1].rm_so >= 0) {
*(l->u.s + rm[1].rm_eo) = '\0';
v = make_str(l->u.s + rm[1].rm_so);
} else {
v = make_int((int)(rm[0].rm_eo - rm[0].rm_so));
}
} else {
if (rp.re_nsub == 0) {
v = make_int(0);
} else {
v = make_str("");
}
}
/* free arguments and pattern buffer */
free_value(l);
free_value(r);
regfree(&rp);
l = v;
}
return l;
}
static VALUE *eval5(void)
{
VALUE *l, *r, *v;
l = eval6();
while (nextarg(":")) {
G.args++;
r = eval6();
v = docolon(l, r);
freev(l);
freev(r);
l = v;
}
return l;
}
static VALUE *eval6(void)
{
static const char keywords[] ALIGN1 =
"quote\0""length\0""match\0""index\0""substr\0";
VALUE *r, *i1, *i2;
static VALUE *l = NULL;
static VALUE *v = NULL;
int key = *G.args ? index_in_strings(keywords, *G.args) + 1 : 0;
if (key == 0) /* not a keyword */
return eval7();
G.args++; /* We have a valid token, so get the next argument. */
if (key == 1) { /* quote */
if (!*G.args)
bb_error_msg_and_die("syntax error");
return str_value(*G.args++);
}
if (key == 2) { /* length */
r = eval6();
tostring(r);
v = int_value(strlen(r->u.s));
freev(r);
} else
l = eval6();
if (key == 3) { /* match */
r = eval6();
v = docolon(l, r);
freev(l);
freev(r);
}
if (key == 4) { /* index */
r = eval6();
tostring(l);
tostring(r);
v = int_value(strcspn(l->u.s, r->u.s) + 1);
if (v->u.i == (arith_t) strlen(l->u.s) + 1)
v->u.i = 0;
freev(l);
freev(r);
}
if (key == 5) { /* substr */
i1 = eval6();
i2 = eval6();
tostring(l);
if (!toarith(i1) || !toarith(i2)
|| i1->u.i > (arith_t) strlen(l->u.s)
|| i1->u.i <= 0 || i2->u.i <= 0)
v = str_value("");
else {
v = xmalloc(sizeof(VALUE));
v->type = STRING;
v->u.s = xstrndup(l->u.s + i1->u.i - 1, i2->u.i);
}
freev(l);
freev(i1);
freev(i2);
}
return v;
}