| 1 |
%{ |
| 2 |
/*- |
| 3 |
* Written by Pace Willisson (pace@blitz.com) |
| 4 |
* and placed in the public domain. |
| 5 |
* |
| 6 |
* Largely rewritten by J.T. Conklin (jtc@wimsey.com) |
| 7 |
* |
| 8 |
* $FreeBSD$ |
| 9 |
*/ |
| 10 |
|
| 11 |
#include <sys/types.h> |
| 12 |
|
| 13 |
#include <ctype.h> |
| 14 |
#include <err.h> |
| 15 |
#include <errno.h> |
| 16 |
#include <inttypes.h> |
| 17 |
#include <limits.h> |
| 18 |
#include <locale.h> |
| 19 |
#include <stdio.h> |
| 20 |
#include <stdlib.h> |
| 21 |
#include <string.h> |
| 22 |
#include <regex.h> |
| 23 |
#include <unistd.h> |
| 24 |
|
| 25 |
/* |
| 26 |
* POSIX specifies a specific error code for syntax errors. We exit |
| 27 |
* with this code for all errors. |
| 28 |
*/ |
| 29 |
#define ERR_EXIT 2 |
| 30 |
|
| 31 |
enum valtype { |
| 32 |
integer, numeric_string, string |
| 33 |
} ; |
| 34 |
|
| 35 |
struct val { |
| 36 |
enum valtype type; |
| 37 |
union { |
| 38 |
char *s; |
| 39 |
intmax_t i; |
| 40 |
} u; |
| 41 |
} ; |
| 42 |
|
| 43 |
char **av; |
| 44 |
int nonposix; |
| 45 |
struct val *result; |
| 46 |
|
| 47 |
void assert_to_integer(struct val *); |
| 48 |
void assert_div(intmax_t, intmax_t); |
| 49 |
void assert_minus(intmax_t, intmax_t, intmax_t); |
| 50 |
void assert_plus(intmax_t, intmax_t, intmax_t); |
| 51 |
void assert_times(intmax_t, intmax_t, intmax_t); |
| 52 |
int compare_vals(struct val *, struct val *); |
| 53 |
void free_value(struct val *); |
| 54 |
int is_integer(const char *); |
| 55 |
int is_string(struct val *); |
| 56 |
int is_zero_or_null(struct val *); |
| 57 |
struct val *make_integer(intmax_t); |
| 58 |
struct val *make_str(const char *); |
| 59 |
struct val *op_and(struct val *, struct val *); |
| 60 |
struct val *op_colon(struct val *, struct val *); |
| 61 |
struct val *op_div(struct val *, struct val *); |
| 62 |
struct val *op_eq(struct val *, struct val *); |
| 63 |
struct val *op_ge(struct val *, struct val *); |
| 64 |
struct val *op_gt(struct val *, struct val *); |
| 65 |
struct val *op_le(struct val *, struct val *); |
| 66 |
struct val *op_lt(struct val *, struct val *); |
| 67 |
struct val *op_minus(struct val *, struct val *); |
| 68 |
struct val *op_ne(struct val *, struct val *); |
| 69 |
struct val *op_or(struct val *, struct val *); |
| 70 |
struct val *op_plus(struct val *, struct val *); |
| 71 |
struct val *op_rem(struct val *, struct val *); |
| 72 |
struct val *op_times(struct val *, struct val *); |
| 73 |
int to_integer(struct val *); |
| 74 |
void to_string(struct val *); |
| 75 |
int yyerror(const char *); |
| 76 |
int yylex(void); |
| 77 |
int yyparse(void); |
| 78 |
|
| 79 |
%} |
| 80 |
|
| 81 |
%union |
| 82 |
{ |
| 83 |
struct val *val; |
| 84 |
} |
| 85 |
|
| 86 |
%left <val> '|' |
| 87 |
%left <val> '&' |
| 88 |
%left <val> '=' '>' '<' GE LE NE |
| 89 |
%left <val> '+' '-' |
| 90 |
%left <val> '*' '/' '%' |
| 91 |
%left <val> ':' |
| 92 |
|
| 93 |
%token <val> TOKEN |
| 94 |
%type <val> start expr |
| 95 |
|
| 96 |
%% |
| 97 |
|
| 98 |
start: expr { result = $$; } |
| 99 |
|
| 100 |
expr: TOKEN |
| 101 |
| '(' expr ')' { $$ = $2; } |
| 102 |
| expr '|' expr { $$ = op_or($1, $3); } |
| 103 |
| expr '&' expr { $$ = op_and($1, $3); } |
| 104 |
| expr '=' expr { $$ = op_eq($1, $3); } |
| 105 |
| expr '>' expr { $$ = op_gt($1, $3); } |
| 106 |
| expr '<' expr { $$ = op_lt($1, $3); } |
| 107 |
| expr GE expr { $$ = op_ge($1, $3); } |
| 108 |
| expr LE expr { $$ = op_le($1, $3); } |
| 109 |
| expr NE expr { $$ = op_ne($1, $3); } |
| 110 |
| expr '+' expr { $$ = op_plus($1, $3); } |
| 111 |
| expr '-' expr { $$ = op_minus($1, $3); } |
| 112 |
| expr '*' expr { $$ = op_times($1, $3); } |
| 113 |
| expr '/' expr { $$ = op_div($1, $3); } |
| 114 |
| expr '%' expr { $$ = op_rem($1, $3); } |
| 115 |
| expr ':' expr { $$ = op_colon($1, $3); } |
| 116 |
; |
| 117 |
|
| 118 |
%% |
| 119 |
|
| 120 |
struct val * |
| 121 |
make_integer(intmax_t i) |
| 122 |
{ |
| 123 |
struct val *vp; |
| 124 |
|
| 125 |
vp = (struct val *)malloc(sizeof(*vp)); |
| 126 |
if (vp == NULL) |
| 127 |
errx(ERR_EXIT, "malloc() failed"); |
| 128 |
|
| 129 |
vp->type = integer; |
| 130 |
vp->u.i = i; |
| 131 |
return (vp); |
| 132 |
} |
| 133 |
|
| 134 |
struct val * |
| 135 |
make_str(const char *s) |
| 136 |
{ |
| 137 |
struct val *vp; |
| 138 |
|
| 139 |
vp = (struct val *)malloc(sizeof(*vp)); |
| 140 |
if (vp == NULL || ((vp->u.s = strdup(s)) == NULL)) |
| 141 |
errx(ERR_EXIT, "malloc() failed"); |
| 142 |
|
| 143 |
if (is_integer(s)) |
| 144 |
vp->type = numeric_string; |
| 145 |
else |
| 146 |
vp->type = string; |
| 147 |
|
| 148 |
return (vp); |
| 149 |
} |
| 150 |
|
| 151 |
void |
| 152 |
free_value(struct val *vp) |
| 153 |
{ |
| 154 |
if (vp->type == string || vp->type == numeric_string) |
| 155 |
free(vp->u.s); |
| 156 |
} |
| 157 |
|
| 158 |
int |
| 159 |
to_integer(struct val *vp) |
| 160 |
{ |
| 161 |
intmax_t i; |
| 162 |
|
| 163 |
/* we can only convert numeric_string to integer, here */ |
| 164 |
if (vp->type == numeric_string) { |
| 165 |
errno = 0; |
| 166 |
i = strtoimax(vp->u.s, (char **)NULL, 10); |
| 167 |
/* just keep as numeric_string, if the conversion fails */ |
| 168 |
if (errno != ERANGE) { |
| 169 |
free(vp->u.s); |
| 170 |
vp->u.i = i; |
| 171 |
vp->type = integer; |
| 172 |
} |
| 173 |
} |
| 174 |
return (vp->type == integer); |
| 175 |
} |
| 176 |
|
| 177 |
void |
| 178 |
assert_to_integer(struct val *vp) |
| 179 |
{ |
| 180 |
if (vp->type == string) |
| 181 |
errx(ERR_EXIT, "not a decimal number: '%s'", vp->u.s); |
| 182 |
if (!to_integer(vp)) |
| 183 |
errx(ERR_EXIT, "operand too large: '%s'", vp->u.s); |
| 184 |
} |
| 185 |
|
| 186 |
void |
| 187 |
to_string(struct val *vp) |
| 188 |
{ |
| 189 |
char *tmp; |
| 190 |
|
| 191 |
if (vp->type == string || vp->type == numeric_string) |
| 192 |
return; |
| 193 |
|
| 194 |
/* |
| 195 |
* log_10(x) ~= 0.3 * log_2(x). Rounding up gives the number |
| 196 |
* of digits; add one each for the sign and terminating null |
| 197 |
* character, respectively. |
| 198 |
*/ |
| 199 |
#define NDIGITS(x) (3 * (sizeof(x) * CHAR_BIT) / 10 + 1 + 1 + 1) |
| 200 |
tmp = malloc(NDIGITS(vp->u.i)); |
| 201 |
if (tmp == NULL) |
| 202 |
errx(ERR_EXIT, "malloc() failed"); |
| 203 |
|
| 204 |
sprintf(tmp, "%jd", vp->u.i); |
| 205 |
vp->type = string; |
| 206 |
vp->u.s = tmp; |
| 207 |
} |
| 208 |
|
| 209 |
int |
| 210 |
is_integer(const char *s) |
| 211 |
{ |
| 212 |
if (nonposix) { |
| 213 |
if (*s == '\0') |
| 214 |
return (1); |
| 215 |
while (isspace((unsigned char)*s)) |
| 216 |
s++; |
| 217 |
} |
| 218 |
if (*s == '-' || (nonposix && *s == '+')) |
| 219 |
s++; |
| 220 |
if (*s == '\0') |
| 221 |
return (0); |
| 222 |
while (isdigit((unsigned char)*s)) |
| 223 |
s++; |
| 224 |
return (*s == '\0'); |
| 225 |
} |
| 226 |
|
| 227 |
int |
| 228 |
is_string(struct val *vp) |
| 229 |
{ |
| 230 |
/* only TRUE if this string is not a valid integer */ |
| 231 |
return (vp->type == string); |
| 232 |
} |
| 233 |
|
| 234 |
int |
| 235 |
yylex(void) |
| 236 |
{ |
| 237 |
char *p; |
| 238 |
|
| 239 |
if (*av == NULL) |
| 240 |
return (0); |
| 241 |
|
| 242 |
p = *av++; |
| 243 |
|
| 244 |
if (strlen(p) == 1) { |
| 245 |
if (strchr("|&=<>+-*/%:()", *p)) |
| 246 |
return (*p); |
| 247 |
} else if (strlen(p) == 2 && p[1] == '=') { |
| 248 |
switch (*p) { |
| 249 |
case '>': return (GE); |
| 250 |
case '<': return (LE); |
| 251 |
case '!': return (NE); |
| 252 |
} |
| 253 |
} |
| 254 |
|
| 255 |
yylval.val = make_str(p); |
| 256 |
return (TOKEN); |
| 257 |
} |
| 258 |
|
| 259 |
int |
| 260 |
is_zero_or_null(struct val *vp) |
| 261 |
{ |
| 262 |
if (vp->type == integer) |
| 263 |
return (vp->u.i == 0); |
| 264 |
|
| 265 |
return (*vp->u.s == 0 || (to_integer(vp) && vp->u.i == 0)); |
| 266 |
} |
| 267 |
|
| 268 |
int |
| 269 |
main(int argc, char *argv[]) |
| 270 |
{ |
| 271 |
int c; |
| 272 |
|
| 273 |
setlocale(LC_ALL, ""); |
| 274 |
if (getenv("EXPR_COMPAT") != NULL |
| 275 |
|| check_utility_compat("expr")) { |
| 276 |
av = argv + 1; |
| 277 |
nonposix = 1; |
| 278 |
} else { |
| 279 |
while ((c = getopt(argc, argv, "e")) != -1) { |
| 280 |
switch (c) { |
| 281 |
case 'e': |
| 282 |
nonposix = 1; |
| 283 |
break; |
| 284 |
default: |
| 285 |
errx(ERR_EXIT, |
| 286 |
"usage: expr [-e] expression\n"); |
| 287 |
} |
| 288 |
} |
| 289 |
av = argv + optind; |
| 290 |
} |
| 291 |
|
| 292 |
yyparse(); |
| 293 |
|
| 294 |
if (result->type == integer) |
| 295 |
printf("%jd\n", result->u.i); |
| 296 |
else |
| 297 |
printf("%s\n", result->u.s); |
| 298 |
|
| 299 |
return (is_zero_or_null(result)); |
| 300 |
} |
| 301 |
|
| 302 |
int |
| 303 |
yyerror(const char *s __unused) |
| 304 |
{ |
| 305 |
errx(ERR_EXIT, "syntax error"); |
| 306 |
} |
| 307 |
|
| 308 |
struct val * |
| 309 |
op_or(struct val *a, struct val *b) |
| 310 |
{ |
| 311 |
if (!is_zero_or_null(a)) { |
| 312 |
free_value(b); |
| 313 |
return (a); |
| 314 |
} |
| 315 |
free_value(a); |
| 316 |
if (!is_zero_or_null(b)) |
| 317 |
return (b); |
| 318 |
free_value(b); |
| 319 |
return (make_integer((intmax_t)0)); |
| 320 |
} |
| 321 |
|
| 322 |
struct val * |
| 323 |
op_and(struct val *a, struct val *b) |
| 324 |
{ |
| 325 |
if (is_zero_or_null(a) || is_zero_or_null(b)) { |
| 326 |
free_value(a); |
| 327 |
free_value(b); |
| 328 |
return (make_integer((intmax_t)0)); |
| 329 |
} else { |
| 330 |
free_value(b); |
| 331 |
return (a); |
| 332 |
} |
| 333 |
} |
| 334 |
|
| 335 |
int |
| 336 |
compare_vals(struct val *a, struct val *b) |
| 337 |
{ |
| 338 |
int r; |
| 339 |
|
| 340 |
if (is_string(a) || is_string(b)) { |
| 341 |
to_string(a); |
| 342 |
to_string(b); |
| 343 |
r = strcoll(a->u.s, b->u.s); |
| 344 |
} else { |
| 345 |
assert_to_integer(a); |
| 346 |
assert_to_integer(b); |
| 347 |
if (a->u.i > b->u.i) |
| 348 |
r = 1; |
| 349 |
else if (a->u.i < b->u.i) |
| 350 |
r = -1; |
| 351 |
else |
| 352 |
r = 0; |
| 353 |
} |
| 354 |
|
| 355 |
free_value(a); |
| 356 |
free_value(b); |
| 357 |
return (r); |
| 358 |
} |
| 359 |
|
| 360 |
struct val * |
| 361 |
op_eq(struct val *a, struct val *b) |
| 362 |
{ |
| 363 |
return (make_integer((intmax_t)(compare_vals(a, b) == 0))); |
| 364 |
} |
| 365 |
|
| 366 |
struct val * |
| 367 |
op_gt(struct val *a, struct val *b) |
| 368 |
{ |
| 369 |
return (make_integer((intmax_t)(compare_vals(a, b) > 0))); |
| 370 |
} |
| 371 |
|
| 372 |
struct val * |
| 373 |
op_lt(struct val *a, struct val *b) |
| 374 |
{ |
| 375 |
return (make_integer((intmax_t)(compare_vals(a, b) < 0))); |
| 376 |
} |
| 377 |
|
| 378 |
struct val * |
| 379 |
op_ge(struct val *a, struct val *b) |
| 380 |
{ |
| 381 |
return (make_integer((intmax_t)(compare_vals(a, b) >= 0))); |
| 382 |
} |
| 383 |
|
| 384 |
struct val * |
| 385 |
op_le(struct val *a, struct val *b) |
| 386 |
{ |
| 387 |
return (make_integer((intmax_t)(compare_vals(a, b) <= 0))); |
| 388 |
} |
| 389 |
|
| 390 |
struct val * |
| 391 |
op_ne(struct val *a, struct val *b) |
| 392 |
{ |
| 393 |
return (make_integer((intmax_t)(compare_vals(a, b) != 0))); |
| 394 |
} |
| 395 |
|
| 396 |
void |
| 397 |
assert_plus(intmax_t a, intmax_t b, intmax_t r) |
| 398 |
{ |
| 399 |
/* |
| 400 |
* sum of two positive numbers must be positive, |
| 401 |
* sum of two negative numbers must be negative |
| 402 |
*/ |
| 403 |
if ((a > 0 && b > 0 && r <= 0) || |
| 404 |
(a < 0 && b < 0 && r >= 0)) |
| 405 |
errx(ERR_EXIT, "overflow"); |
| 406 |
} |
| 407 |
|
| 408 |
struct val * |
| 409 |
op_plus(struct val *a, struct val *b) |
| 410 |
{ |
| 411 |
struct val *r; |
| 412 |
|
| 413 |
assert_to_integer(a); |
| 414 |
assert_to_integer(b); |
| 415 |
r = make_integer(a->u.i + b->u.i); |
| 416 |
assert_plus(a->u.i, b->u.i, r->u.i); |
| 417 |
|
| 418 |
free_value(a); |
| 419 |
free_value(b); |
| 420 |
return (r); |
| 421 |
} |
| 422 |
|
| 423 |
void |
| 424 |
assert_minus(intmax_t a, intmax_t b, intmax_t r) |
| 425 |
{ |
| 426 |
/* special case subtraction of INTMAX_MIN */ |
| 427 |
if (b == INTMAX_MIN && a < 0) |
| 428 |
errx(ERR_EXIT, "overflow"); |
| 429 |
/* check addition of negative subtrahend */ |
| 430 |
assert_plus(a, -b, r); |
| 431 |
} |
| 432 |
|
| 433 |
struct val * |
| 434 |
op_minus(struct val *a, struct val *b) |
| 435 |
{ |
| 436 |
struct val *r; |
| 437 |
|
| 438 |
assert_to_integer(a); |
| 439 |
assert_to_integer(b); |
| 440 |
r = make_integer(a->u.i - b->u.i); |
| 441 |
assert_minus(a->u.i, b->u.i, r->u.i); |
| 442 |
|
| 443 |
free_value(a); |
| 444 |
free_value(b); |
| 445 |
return (r); |
| 446 |
} |
| 447 |
|
| 448 |
void |
| 449 |
assert_times(intmax_t a, intmax_t b, intmax_t r) |
| 450 |
{ |
| 451 |
/* |
| 452 |
* if first operand is 0, no overflow is possible, |
| 453 |
* else result of division test must match second operand |
| 454 |
*/ |
| 455 |
if (a != 0 && r / a != b) |
| 456 |
errx(ERR_EXIT, "overflow"); |
| 457 |
} |
| 458 |
|
| 459 |
struct val * |
| 460 |
op_times(struct val *a, struct val *b) |
| 461 |
{ |
| 462 |
struct val *r; |
| 463 |
|
| 464 |
assert_to_integer(a); |
| 465 |
assert_to_integer(b); |
| 466 |
r = make_integer(a->u.i * b->u.i); |
| 467 |
assert_times(a->u.i, b->u.i, r->u.i); |
| 468 |
|
| 469 |
free_value(a); |
| 470 |
free_value(b); |
| 471 |
return (r); |
| 472 |
} |
| 473 |
|
| 474 |
void |
| 475 |
assert_div(intmax_t a, intmax_t b) |
| 476 |
{ |
| 477 |
if (b == 0) |
| 478 |
errx(ERR_EXIT, "division by zero"); |
| 479 |
/* only INTMAX_MIN / -1 causes overflow */ |
| 480 |
if (a == INTMAX_MIN && b == -1) |
| 481 |
errx(ERR_EXIT, "overflow"); |
| 482 |
} |
| 483 |
|
| 484 |
struct val * |
| 485 |
op_div(struct val *a, struct val *b) |
| 486 |
{ |
| 487 |
struct val *r; |
| 488 |
|
| 489 |
assert_to_integer(a); |
| 490 |
assert_to_integer(b); |
| 491 |
/* assert based on operands only, not on result */ |
| 492 |
assert_div(a->u.i, b->u.i); |
| 493 |
r = make_integer(a->u.i / b->u.i); |
| 494 |
|
| 495 |
free_value(a); |
| 496 |
free_value(b); |
| 497 |
return (r); |
| 498 |
} |
| 499 |
|
| 500 |
struct val * |
| 501 |
op_rem(struct val *a, struct val *b) |
| 502 |
{ |
| 503 |
struct val *r; |
| 504 |
|
| 505 |
assert_to_integer(a); |
| 506 |
assert_to_integer(b); |
| 507 |
/* pass a=1 to only check for div by zero */ |
| 508 |
assert_div(1, b->u.i); |
| 509 |
r = make_integer(a->u.i % b->u.i); |
| 510 |
|
| 511 |
free_value(a); |
| 512 |
free_value(b); |
| 513 |
return (r); |
| 514 |
} |
| 515 |
|
| 516 |
struct val * |
| 517 |
op_colon(struct val *a, struct val *b) |
| 518 |
{ |
| 519 |
regex_t rp; |
| 520 |
regmatch_t rm[2]; |
| 521 |
char errbuf[256]; |
| 522 |
int eval; |
| 523 |
struct val *v; |
| 524 |
|
| 525 |
/* coerce both arguments to strings */ |
| 526 |
to_string(a); |
| 527 |
to_string(b); |
| 528 |
|
| 529 |
/* compile regular expression */ |
| 530 |
if ((eval = regcomp(&rp, b->u.s, 0)) != 0) { |
| 531 |
regerror(eval, &rp, errbuf, sizeof(errbuf)); |
| 532 |
errx(ERR_EXIT, "%s", errbuf); |
| 533 |
} |
| 534 |
|
| 535 |
/* compare string against pattern */ |
| 536 |
/* remember that patterns are anchored to the beginning of the line */ |
| 537 |
if (regexec(&rp, a->u.s, (size_t)2, rm, 0) == 0 && rm[0].rm_so == 0) |
| 538 |
if (rm[1].rm_so >= 0) { |
| 539 |
*(a->u.s + rm[1].rm_eo) = '\0'; |
| 540 |
v = make_str(a->u.s + rm[1].rm_so); |
| 541 |
|
| 542 |
} else |
| 543 |
v = make_integer((intmax_t)(rm[0].rm_eo - rm[0].rm_so)); |
| 544 |
else |
| 545 |
if (rp.re_nsub == 0) |
| 546 |
v = make_integer((intmax_t)0); |
| 547 |
else |
| 548 |
v = make_str(""); |
| 549 |
|
| 550 |
/* free arguments and pattern buffer */ |
| 551 |
free_value(a); |
| 552 |
free_value(b); |
| 553 |
regfree(&rp); |
| 554 |
|
| 555 |
return (v); |
| 556 |
} |
