| /* See LICENSE file for copyright and license details. */ |
| #include <limits.h> |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <string.h> |
| |
| #include "utf.h" |
| #include "util.h" |
| |
| /* tokens, one-character operators represent themselves */ |
| enum { |
| VAL = CHAR_MAX + 1, GE, LE, NE |
| }; |
| |
| struct val { |
| char *str; |
| long long num; |
| }; |
| |
| static void |
| enan(struct val *v) |
| { |
| if (!v->str) |
| return; |
| enprintf(2, "syntax error: expected integer, got %s\n", v->str); |
| } |
| |
| static void |
| ezero(struct val *v) |
| { |
| if (v->num != 0) |
| return; |
| enprintf(2, "division by zero\n"); |
| } |
| |
| static int |
| valcmp(struct val *a, struct val *b) |
| { |
| int ret; |
| char buf[BUFSIZ]; |
| |
| if (!a->str && !b->str) { |
| ret = (a->num > b->num) - (a->num < b->num); |
| } else if (a->str && !b->str) { |
| snprintf(buf, sizeof(buf), "%lld", b->num); |
| ret = strcmp(a->str, buf); |
| } else if (!a->str && b->str) { |
| snprintf(buf, sizeof(buf), "%lld", a->num); |
| ret = strcmp(buf, b->str); |
| } else { |
| ret = strcmp(a->str, b->str); |
| } |
| |
| return ret; |
| } |
| |
| static void |
| match(struct val *vstr, struct val *vregx, struct val *ret) |
| { |
| regex_t re; |
| regmatch_t matches[2]; |
| long long d; |
| size_t anchlen; |
| char strbuf[BUFSIZ], regxbuf[BUFSIZ], |
| *s, *p, *anchreg, *str, *regx; |
| const char *errstr; |
| |
| if (!vstr->str) { |
| snprintf(strbuf, sizeof(strbuf), "%lld", vstr->num); |
| str = strbuf; |
| } else { |
| str = vstr->str; |
| } |
| |
| if (!vregx->str) { |
| snprintf(regxbuf, sizeof(regxbuf), "%lld", vregx->num); |
| regx = regxbuf; |
| } else { |
| regx = vregx->str; |
| } |
| |
| /* anchored regex */ |
| anchlen = strlen(regx) + 1 + 1; |
| anchreg = emalloc(anchlen); |
| estrlcpy(anchreg, "^", anchlen); |
| estrlcat(anchreg, regx, anchlen); |
| enregcomp(3, &re, anchreg, 0); |
| free(anchreg); |
| |
| if (regexec(&re, str, 2, matches, 0)) { |
| regfree(&re); |
| ret->str = re.re_nsub ? "" : NULL; |
| return; |
| } else if (re.re_nsub) { |
| regfree(&re); |
| |
| s = str + matches[1].rm_so; |
| p = str + matches[1].rm_eo; |
| *p = '\0'; |
| |
| d = strtonum(s, LLONG_MIN, LLONG_MAX, &errstr); |
| if (!errstr) { |
| ret->num = d; |
| return; |
| } else { |
| ret->str = enstrdup(3, s); |
| return; |
| } |
| } else { |
| regfree(&re); |
| str += matches[0].rm_so; |
| ret->num = utfnlen(str, matches[0].rm_eo - matches[0].rm_so); |
| return; |
| } |
| } |
| |
| static void |
| doop(int *ophead, int *opp, struct val *valhead, struct val *valp) |
| { |
| struct val ret = { .str = NULL, .num = 0 }, *a, *b; |
| int op; |
| |
| /* an operation "a op b" needs an operator and two values */ |
| if (opp[-1] == '(') |
| enprintf(2, "syntax error: extra (\n"); |
| if (valp - valhead < 2) |
| enprintf(2, "syntax error: missing expression or extra operator\n"); |
| |
| a = valp - 2; |
| b = valp - 1; |
| op = opp[-1]; |
| |
| switch (op) { |
| case '|': |
| if ( a->str && *a->str) ret.str = a->str; |
| else if (!a->str && a->num) ret.num = a->num; |
| else if ( b->str && *b->str) ret.str = b->str; |
| else ret.num = b->num; |
| break; |
| case '&': |
| if (((a->str && *a->str) || a->num) && |
| ((b->str && *b->str) || b->num)) { |
| ret.str = a->str; |
| ret.num = a->num; |
| } |
| break; |
| |
| case '=': ret.num = (valcmp(a, b) == 0); break; |
| case '>': ret.num = (valcmp(a, b) > 0); break; |
| case GE : ret.num = (valcmp(a, b) >= 0); break; |
| case '<': ret.num = (valcmp(a, b) < 0); break; |
| case LE : ret.num = (valcmp(a, b) <= 0); break; |
| case NE : ret.num = (valcmp(a, b) != 0); break; |
| |
| case '+': enan(a); enan(b); ret.num = a->num + b->num; break; |
| case '-': enan(a); enan(b); ret.num = a->num - b->num; break; |
| case '*': enan(a); enan(b); ret.num = a->num * b->num; break; |
| case '/': enan(a); enan(b); ezero(b); ret.num = a->num / b->num; break; |
| case '%': enan(a); enan(b); ezero(b); ret.num = a->num % b->num; break; |
| |
| case ':': match(a, b, &ret); break; |
| } |
| |
| valp[-2] = ret; |
| } |
| |
| static int |
| lex(char *s, struct val *v) |
| { |
| long long d; |
| int type = VAL; |
| char *ops = "|&=><+-*/%():"; |
| const char *errstr; |
| |
| d = strtonum(s, LLONG_MIN, LLONG_MAX, &errstr); |
| |
| if (!errstr) { |
| /* integer */ |
| v->num = d; |
| } else if (s[0] && strchr(ops, s[0]) && !s[1]) { |
| /* one-char operand */ |
| type = s[0]; |
| } else if (s[0] && strchr("><!", s[0]) && s[1] == '=' && !s[2]) { |
| /* two-char operand */ |
| type = (s[0] == '>') ? GE : (s[0] == '<') ? LE : NE; |
| } else { |
| /* string */ |
| v->str = s; |
| } |
| |
| return type; |
| } |
| |
| static int |
| parse(char *expr[], int numexpr) |
| { |
| struct val valhead[numexpr], *valp = valhead, v = { .str = NULL, .num = 0 }; |
| int ophead[numexpr], *opp = ophead, type, lasttype = 0; |
| char prec[] = { |
| [ 0 ] = 0, [VAL] = 0, ['('] = 0, [')'] = 0, |
| ['|'] = 1, |
| ['&'] = 2, |
| ['='] = 3, ['>'] = 3, [GE] = 3, ['<'] = 3, [LE] = 3, [NE] = 3, |
| ['+'] = 4, ['-'] = 4, |
| ['*'] = 5, ['/'] = 5, ['%'] = 5, |
| [':'] = 6, |
| }; |
| |
| for (; *expr; expr++) { |
| switch ((type = lex(*expr, &v))) { |
| case VAL: |
| valp->str = v.str; |
| valp->num = v.num; |
| valp++; |
| break; |
| case '(': |
| *opp++ = type; |
| break; |
| case ')': |
| if (lasttype == '(') |
| enprintf(2, "syntax error: empty ( )\n"); |
| while (opp > ophead && opp[-1] != '(') |
| doop(ophead, opp--, valhead, valp--); |
| if (opp == ophead) |
| enprintf(2, "syntax error: extra )\n"); |
| opp--; |
| break; |
| default: /* operator */ |
| if (prec[lasttype]) |
| enprintf(2, "syntax error: extra operator\n"); |
| while (opp > ophead && prec[opp[-1]] >= prec[type]) |
| doop(ophead, opp--, valhead, valp--); |
| *opp++ = type; |
| break; |
| } |
| lasttype = type; |
| v.str = NULL; |
| v.num = 0; |
| } |
| while (opp > ophead) |
| doop(ophead, opp--, valhead, valp--); |
| if (valp == valhead) |
| enprintf(2, "syntax error: missing expression\n"); |
| if (--valp > valhead) |
| enprintf(2, "syntax error: extra expression\n"); |
| |
| if (valp->str) |
| puts(valp->str); |
| else |
| printf("%lld\n", valp->num); |
| |
| return (valp->str && *valp->str) || valp->num; |
| } |
| |
| int |
| main(int argc, char *argv[]) |
| { |
| int ret; |
| |
| argv0 = argv[0], argc--, argv++; |
| |
| ret = !parse(argv, argc); |
| |
| if (fshut(stdout, "<stdout>")) |
| ret = 3; |
| |
| return ret; |
| } |