| 1 | /* -*-c-*- |
| 2 | * |
| 3 | * $Id: sw_env.c,v 1.1 1999/06/02 16:53:35 mdw Exp $ |
| 4 | * |
| 5 | * Mangling of environment variables |
| 6 | * |
| 7 | * (c) 1999 EBI |
| 8 | */ |
| 9 | |
| 10 | /*----- Licensing notice --------------------------------------------------* |
| 11 | * |
| 12 | * This file is part of sw-tools. |
| 13 | * |
| 14 | * sw-tools is free software; you can redistribute it and/or modify |
| 15 | * it under the terms of the GNU General Public License as published by |
| 16 | * the Free Software Foundation; either version 2 of the License, or |
| 17 | * (at your option) any later version. |
| 18 | * |
| 19 | * sw-tools is distributed in the hope that it will be useful, |
| 20 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 21 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 22 | * GNU General Public License for more details. |
| 23 | * |
| 24 | * You should have received a copy of the GNU General Public License |
| 25 | * along with sw-tools; if not, write to the Free Software Foundation, |
| 26 | * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
| 27 | */ |
| 28 | |
| 29 | /*----- Revision history --------------------------------------------------* |
| 30 | * |
| 31 | * $Log: sw_env.c,v $ |
| 32 | * Revision 1.1 1999/06/02 16:53:35 mdw |
| 33 | * Initial revision |
| 34 | * |
| 35 | */ |
| 36 | |
| 37 | /*----- Header files ------------------------------------------------------*/ |
| 38 | |
| 39 | #include "config.h" |
| 40 | |
| 41 | #include <ctype.h> |
| 42 | #include <errno.h> |
| 43 | #include <stdio.h> |
| 44 | #include <stdlib.h> |
| 45 | #include <string.h> |
| 46 | |
| 47 | #include <unistd.h> |
| 48 | #include <sys/wait.h> |
| 49 | |
| 50 | #ifndef DECL_ENVIRON |
| 51 | extern char **environ; |
| 52 | #endif |
| 53 | |
| 54 | #include <mLib/alloc.h> |
| 55 | #include <mLib/dstr.h> |
| 56 | #include <mLib/report.h> |
| 57 | #include <mLib/sym.h> |
| 58 | |
| 59 | #include "sw_env.h" |
| 60 | |
| 61 | /*----- Data structures ---------------------------------------------------*/ |
| 62 | |
| 63 | typedef struct var { |
| 64 | sym_base _base; |
| 65 | char *v; |
| 66 | } var; |
| 67 | |
| 68 | /*----- Main code ---------------------------------------------------------*/ |
| 69 | |
| 70 | /* --- @env_get@ --- * |
| 71 | * |
| 72 | * Arguments: @sym_table *t@ = pointer to a symbol table |
| 73 | * @const char *name@ = pointer to variable name to look up |
| 74 | * |
| 75 | * Returns: Pointer to corresponding value string, or null. |
| 76 | * |
| 77 | * Use: Looks up an environment variable in the table and returns its |
| 78 | * value. If the variable can't be found, a null pointer is |
| 79 | * returned. |
| 80 | */ |
| 81 | |
| 82 | char *env_get(sym_table *t, const char *name) |
| 83 | { |
| 84 | var *e = sym_find(t, name, -1, 0, 0); |
| 85 | return (e ? e->v : 0); |
| 86 | } |
| 87 | |
| 88 | /* --- @env_put@ --- * |
| 89 | * |
| 90 | * Arguments: @sym_table *t@ = pointer to a symbol table |
| 91 | * @const char *name@ = pointer to variable name to set |
| 92 | * @const char *value@ = pointer to value string to assign |
| 93 | * |
| 94 | * Returns: --- |
| 95 | * |
| 96 | * Use: Assigns a value to a variable. If the @name@ contains an |
| 97 | * equals character, then it's assumed to be of the form |
| 98 | * `VAR=VALUE' and @value@ argument is ignored. Otherwise, if |
| 99 | * @value@ is null, the variable is deleted. Finally, the |
| 100 | * normal case: @name@ is a plain name, and @value@ is a normal |
| 101 | * string causes the variable to be assigned the value in the |
| 102 | * way you'd expect. |
| 103 | */ |
| 104 | |
| 105 | void env_put(sym_table *t, const char *name, const char *value) |
| 106 | { |
| 107 | char *q = 0; |
| 108 | |
| 109 | /* --- Sort out the mess with `NAME=VALUE' forms --- */ |
| 110 | |
| 111 | { |
| 112 | size_t eq = strcspn(name, "="); |
| 113 | if (name[eq] == '=') { |
| 114 | q = xmalloc(eq + 1); |
| 115 | memcpy(q, name, eq); |
| 116 | q[eq] = 0; |
| 117 | value = name + eq + 1; |
| 118 | name = q; |
| 119 | } |
| 120 | } |
| 121 | |
| 122 | /* --- Read the current value --- */ |
| 123 | |
| 124 | if (!value) { |
| 125 | var *v; |
| 126 | if ((v = sym_find(t, name, -1, 0, 0)) != 0) { |
| 127 | free(v->v); |
| 128 | sym_remove(t, v); |
| 129 | } |
| 130 | } else { |
| 131 | unsigned found; |
| 132 | var *v = sym_find(t, name, -1, sizeof(*v), &found); |
| 133 | if (found) |
| 134 | free(v->v); |
| 135 | v->v = xstrdup(value); |
| 136 | } |
| 137 | |
| 138 | /* --- Tidying --- */ |
| 139 | |
| 140 | if (q) |
| 141 | free(q); |
| 142 | } |
| 143 | |
| 144 | /* --- @env_import@ --- * |
| 145 | * |
| 146 | * Arguments: @sym_table *t@ = pointer to a symbol table |
| 147 | * @char **env@ = pointer to an environment list |
| 148 | * |
| 149 | * Returns: --- |
| 150 | * |
| 151 | * Use: Inserts all of the environment variables listed into a symbol |
| 152 | * table for rapid access. Equivalent to a lot of calls to |
| 153 | * @env_put@. |
| 154 | */ |
| 155 | |
| 156 | void env_import(sym_table *t, char **env) |
| 157 | { |
| 158 | while (*env) { |
| 159 | env_put(t, *env, 0); |
| 160 | env++; |
| 161 | } |
| 162 | } |
| 163 | |
| 164 | /* --- @env_export@ --- * |
| 165 | * |
| 166 | * Arguments: @sym_table *t@ = pointer to a symbol table |
| 167 | * |
| 168 | * Returns: A big environment list. |
| 169 | * |
| 170 | * Use: Extracts an environment table from a symbol table |
| 171 | * representation of an environment. The table and all of the |
| 172 | * strings are in one big block allocated from the heap. |
| 173 | */ |
| 174 | |
| 175 | char **env_export(sym_table *t) |
| 176 | { |
| 177 | size_t n = 1; |
| 178 | size_t sz = 0; |
| 179 | sym_iter i; |
| 180 | var *v; |
| 181 | char **env; |
| 182 | char *p, **pp; |
| 183 | |
| 184 | /* --- Work out sizes for everything --- */ |
| 185 | |
| 186 | for (sym_mkiter(&i, t); (v = sym_next(&i)) != 0; ) { |
| 187 | n++; |
| 188 | sz += strlen(SYM_NAME(v)) + strlen(v->v) + 2; |
| 189 | } |
| 190 | |
| 191 | /* --- Allocate the big chunk of memory --- */ |
| 192 | |
| 193 | env = pp = xmalloc(n * sizeof(char *) + sz); |
| 194 | p = (char *)(env + n); |
| 195 | |
| 196 | /* --- Dump the output in the big chunk of memory --- */ |
| 197 | |
| 198 | for (sym_mkiter(&i, t); (v = sym_next(&i)) != 0; ) { |
| 199 | const char *name = SYM_NAME(v); |
| 200 | size_t nlen = strlen(name), vlen = strlen(v->v); |
| 201 | *pp++ = p; |
| 202 | memcpy(p, name, nlen); p += nlen; |
| 203 | *p++ = '='; |
| 204 | memcpy(p, v->v, vlen); p += vlen; |
| 205 | *p++ = 0; |
| 206 | } |
| 207 | *pp++ = 0; |
| 208 | return (env); |
| 209 | } |
| 210 | |
| 211 | /* --- @env_destroy@ --- * |
| 212 | * |
| 213 | * Arguments: @sym_table *t@ = pointer to symbol table |
| 214 | * |
| 215 | * Returns: --- |
| 216 | * |
| 217 | * Use: Destroys all the variables in the symbol table. |
| 218 | */ |
| 219 | |
| 220 | void env_destroy(sym_table *t) |
| 221 | { |
| 222 | sym_iter i; |
| 223 | var *v; |
| 224 | |
| 225 | for (sym_mkiter(&i, t); (v = sym_next(&i)) != 0; ) |
| 226 | free(v->v); |
| 227 | sym_destroy(t); |
| 228 | } |
| 229 | |
| 230 | /* --- @env_error@ --- * |
| 231 | * |
| 232 | * Arguments: @int e@ = error code |
| 233 | * |
| 234 | * Returns: String representation of error. |
| 235 | * |
| 236 | * Use: Transforms an error into something a user can understand. |
| 237 | */ |
| 238 | |
| 239 | const char *env_error(int e) |
| 240 | { |
| 241 | const char *tab[] = { |
| 242 | "Everything is fine", |
| 243 | "Unexpected end-of-file", |
| 244 | "Bad character in variable name", |
| 245 | "Bad parameter substitution", |
| 246 | "Mismatched quote", |
| 247 | "Missing or spurious `}'", |
| 248 | "<see errno>", |
| 249 | "Internal error" |
| 250 | }; |
| 251 | if (e == ENV_SYSTEM) |
| 252 | return (strerror(errno)); |
| 253 | else |
| 254 | return (tab[e]); |
| 255 | } |
| 256 | |
| 257 | /* --- @peek@ --- * |
| 258 | * |
| 259 | * Arguments: @FILE *fp@ = stream to read from |
| 260 | * |
| 261 | * Returns: Next nonwhitespace character. |
| 262 | * |
| 263 | * Use: Advances the file position past whitespace characters, and |
| 264 | * returns the following nonwhitespace character. The character |
| 265 | * is not `read'. |
| 266 | */ |
| 267 | |
| 268 | static int peek(FILE *fp) |
| 269 | { |
| 270 | int ch; |
| 271 | |
| 272 | do { |
| 273 | ch = getc(fp); |
| 274 | if (ch == EOF) |
| 275 | return (EOF); |
| 276 | } while (isspace((unsigned char)ch)); |
| 277 | ungetc(ch, fp); |
| 278 | return (ch); |
| 279 | } |
| 280 | |
| 281 | /* --- @env_var@ --- * |
| 282 | * |
| 283 | * Arguments: @sym_table *t@ = pointer to symbol table |
| 284 | * @FILE *fp@ = pointer to stream to read from |
| 285 | * @dstr *d@ = pointer to output variable |
| 286 | * |
| 287 | * Returns: One of the @ENV_@ constants. |
| 288 | * |
| 289 | * Use: Scans a variable name from the input stream. |
| 290 | */ |
| 291 | |
| 292 | int env_var(sym_table *t, FILE *fp, dstr *d) |
| 293 | { |
| 294 | int ch = getc(fp); |
| 295 | |
| 296 | if (ch == EOF) |
| 297 | return (ENV_EOF); |
| 298 | if (ch != '_' && !isalpha((unsigned char)ch)) |
| 299 | return (ENV_VCHAR); |
| 300 | for (;;) { |
| 301 | DPUTC(d, ch); |
| 302 | ch = getc(fp); |
| 303 | if (ch == EOF || (ch != '_' && !isalnum((unsigned char)ch))) |
| 304 | break; |
| 305 | } |
| 306 | ungetc(ch, fp); |
| 307 | DPUTZ(d); |
| 308 | return (ENV_OK); |
| 309 | } |
| 310 | |
| 311 | /* --- @cmdsubst@ --- * |
| 312 | * |
| 313 | * Arguments: @sym_table *t@ = pointer to symbol table |
| 314 | * @FILE *fp@ = pointer to stream to read from |
| 315 | * @dstr *d@ = pointer to output variable |
| 316 | * @unsigned f@ = interesting flags |
| 317 | * |
| 318 | * Returns: An @ENV_@ magic code. |
| 319 | * |
| 320 | * Use: Rips a command line out of the input stream and writes the |
| 321 | * output of the command to the variable. The parsing has some |
| 322 | * bizarre artifacts, but it's fairly serviceable. |
| 323 | */ |
| 324 | |
| 325 | static int cmdsubst(sym_table *t, FILE *fp, dstr *d, unsigned f) |
| 326 | { |
| 327 | int term = (f & EVF_BACKTICK) ? '`' : ')'; |
| 328 | int argc = 1; |
| 329 | size_t l = d->len; |
| 330 | pid_t kid; |
| 331 | int fd[2]; |
| 332 | int e; |
| 333 | char **argv; |
| 334 | |
| 335 | /* --- Snarfle the arguments --- */ |
| 336 | |
| 337 | f &= ~EVF_INCSPC; |
| 338 | while (peek(fp) != term) { |
| 339 | if ((e = env_value(t, fp, d, f)) != ENV_OK) |
| 340 | return (e); |
| 341 | DPUTC(d, 0); |
| 342 | argc++; |
| 343 | } |
| 344 | getc(fp); |
| 345 | if (argc == 1) { |
| 346 | d->len = l; |
| 347 | return (ENV_OK); |
| 348 | } |
| 349 | |
| 350 | /* --- Make the @argv@ array --- */ |
| 351 | |
| 352 | { |
| 353 | char *p = d->buf + l; |
| 354 | char *lim = d->buf + d->len; |
| 355 | char **v; |
| 356 | |
| 357 | v = argv = xmalloc(argc * sizeof(char *)); |
| 358 | while (p < lim) { |
| 359 | *v++ = p; |
| 360 | while (*p) { |
| 361 | p++; |
| 362 | if (p >= lim) |
| 363 | goto done; |
| 364 | } |
| 365 | p++; |
| 366 | } |
| 367 | done:; |
| 368 | *v++ = 0; |
| 369 | } |
| 370 | |
| 371 | /* --- Do the fork/exec thing --- */ |
| 372 | |
| 373 | if (pipe(fd)) |
| 374 | goto fail_0; |
| 375 | if ((kid = fork()) < 0) |
| 376 | goto fail_1; |
| 377 | |
| 378 | if (kid == 0) { |
| 379 | close(fd[0]); |
| 380 | if (fd[1] != 1) { |
| 381 | dup2(fd[1], 1); |
| 382 | close(fd[1]); |
| 383 | } |
| 384 | environ = env_export(t); |
| 385 | execvp(argv[0], argv); |
| 386 | _exit(127); |
| 387 | } |
| 388 | |
| 389 | d->len = l; |
| 390 | close(fd[1]); |
| 391 | for (;;) { |
| 392 | char buf[4096]; |
| 393 | ssize_t n = read(fd[0], buf, sizeof(buf)); |
| 394 | if (n <= 0) |
| 395 | break; |
| 396 | DPUTM(d, buf, n); |
| 397 | } |
| 398 | close(fd[0]); |
| 399 | waitpid(kid, 0, 0); |
| 400 | l = d->len; |
| 401 | while (l > 0 && d->buf[l - 1] == '\n') |
| 402 | l--; |
| 403 | d->len = l; |
| 404 | free(argv); |
| 405 | return (ENV_OK); |
| 406 | |
| 407 | fail_1: |
| 408 | close(fd[0]); |
| 409 | close(fd[1]); |
| 410 | fail_0: |
| 411 | free(argv); |
| 412 | return (ENV_SYSTEM); |
| 413 | } |
| 414 | |
| 415 | /* --- @env_value@ --- * |
| 416 | * |
| 417 | * Arguments: @sym_table *t@ = pointer to symbol table |
| 418 | * @FILE *fp@ = pointer to stream to read from |
| 419 | * @dstr *d@ = pointer to output variable |
| 420 | * @unsigned f@ = various interesting flags |
| 421 | * |
| 422 | * Returns: 0 if OK, @EOF@ if end-of-file encountered, or >0 on error. |
| 423 | * |
| 424 | * Use: Scans a value from the input stream. The value read may be |
| 425 | * quoted in a Bourne-shell sort of a way, and contain Bourne- |
| 426 | * shell-like parameter substitutions. Some substitutions |
| 427 | * aren't available because they're too awkward to implement. |
| 428 | */ |
| 429 | |
| 430 | int env_value(sym_table *t, FILE *fp, dstr *d, unsigned f) |
| 431 | { |
| 432 | enum { Q_NONE, Q_SINGLE, Q_DOUBLE, Q_BACK } qt = Q_NONE; |
| 433 | int ch; |
| 434 | |
| 435 | do { |
| 436 | ch = getc(fp); |
| 437 | if (ch == EOF) |
| 438 | return (ENV_EOF); |
| 439 | } while ((f & EVF_INITSPC) && isspace((unsigned char)ch)); |
| 440 | |
| 441 | for (;; ch = getc(fp)) { |
| 442 | |
| 443 | /* --- Sort out the current character --- */ |
| 444 | |
| 445 | if (ch == EOF) break; |
| 446 | |
| 447 | /* --- A backslash escapes the next character --- */ |
| 448 | |
| 449 | if (ch == '\\') { |
| 450 | if ((ch = getc(fp)) == EOF) break; |
| 451 | else if (ch != '\n') |
| 452 | DPUTC(d, ch); |
| 453 | continue; |
| 454 | } |
| 455 | |
| 456 | /* --- A single quote starts single-quoting, unless quoted --- * |
| 457 | * |
| 458 | * Do the single-quoted snarf here rather than fiddling with anything |
| 459 | * else. |
| 460 | */ |
| 461 | |
| 462 | if (ch == '\'' && qt == Q_NONE) { |
| 463 | qt = Q_SINGLE; |
| 464 | for (;;) { |
| 465 | if ((ch = getc(fp)) == EOF) goto done; |
| 466 | if (ch == '\'') break; |
| 467 | DPUTC(d, ch); |
| 468 | } |
| 469 | qt = Q_NONE; |
| 470 | continue; |
| 471 | } |
| 472 | |
| 473 | /* --- A backtick does the obvious thing --- */ |
| 474 | |
| 475 | if (ch == '`' && !(f & EVF_BACKTICK)) { |
| 476 | int e; |
| 477 | if ((e = cmdsubst(t, fp, d, f | EVF_BACKTICK)) != ENV_OK) |
| 478 | return (e); |
| 479 | continue; |
| 480 | } |
| 481 | |
| 482 | /* --- Handle double-quoted text --- */ |
| 483 | |
| 484 | if (ch == '\"') { |
| 485 | if (qt == Q_DOUBLE) |
| 486 | qt = Q_NONE; |
| 487 | else if (qt == Q_NONE) |
| 488 | qt = Q_DOUBLE; |
| 489 | else |
| 490 | return (ENV_INTERNAL); |
| 491 | continue; |
| 492 | } |
| 493 | |
| 494 | /* --- Handle variable references and similar magic --- */ |
| 495 | |
| 496 | if (ch == '$') { |
| 497 | size_t l = d->len; |
| 498 | int e; |
| 499 | char *v; |
| 500 | char *vn; |
| 501 | |
| 502 | /* --- Read one character ahead --- */ |
| 503 | |
| 504 | if ((ch = getc(fp)) == EOF) goto done; |
| 505 | |
| 506 | /* --- An alphabetic means this is a direct reference --- */ |
| 507 | |
| 508 | if (ch == '_' || isalpha(ch)) { |
| 509 | ungetc(ch, fp); |
| 510 | if ((e = env_var(t, fp, d)) != ENV_OK) return (e); |
| 511 | d->len = l; |
| 512 | if ((v = env_get(t, d->buf + l)) != 0) |
| 513 | DPUTS(d, v); |
| 514 | } |
| 515 | |
| 516 | /* --- A brace means this is a more complex substitution --- */ |
| 517 | |
| 518 | else if (ch == '{') { |
| 519 | if ((e = env_var(t, fp, d)) != ENV_OK) |
| 520 | return (e); |
| 521 | d->len = l; |
| 522 | v = env_get(t, d->buf + l); |
| 523 | |
| 524 | again: |
| 525 | ch = getc(fp); |
| 526 | switch (ch) { |
| 527 | |
| 528 | case EOF: |
| 529 | goto done; |
| 530 | |
| 531 | case '}': |
| 532 | if (v) |
| 533 | DPUTS(d, v); |
| 534 | ungetc(ch, fp); |
| 535 | break; |
| 536 | |
| 537 | case ':': |
| 538 | if (v && !*v) |
| 539 | v = 0; |
| 540 | goto again; /* `::' and `:}' should be errors */ |
| 541 | |
| 542 | case '+': |
| 543 | if (v) |
| 544 | v = 0; |
| 545 | else |
| 546 | v = ""; |
| 547 | /* Drop through hackily */ |
| 548 | |
| 549 | case '-': |
| 550 | if (v) { |
| 551 | DPUTS(d, v); |
| 552 | l = d->len; |
| 553 | } |
| 554 | if ((e = env_value(t, fp, d, EVF_INCSPC)) != ENV_OK) |
| 555 | return (e); |
| 556 | if (v) |
| 557 | d->len = l; |
| 558 | break; |
| 559 | |
| 560 | case '=': |
| 561 | if (v) { |
| 562 | DPUTS(d, v); |
| 563 | l = d->len; |
| 564 | if ((e = env_value(t, fp, d, EVF_INCSPC)) != ENV_OK) |
| 565 | return (e); |
| 566 | d->len = l; |
| 567 | } else { |
| 568 | vn = xstrdup(d->buf + l); |
| 569 | if ((e = env_value(t, fp, d, EVF_INCSPC)) != ENV_OK) |
| 570 | return (e); |
| 571 | if (!(f & EVF_SKIP)) |
| 572 | env_put(t, vn, d->buf + l); |
| 573 | free(vn); |
| 574 | } |
| 575 | break; |
| 576 | |
| 577 | default: |
| 578 | return (ENV_SUBST); |
| 579 | } |
| 580 | if (getc(fp) != '}') |
| 581 | return (ENV_BRACE); |
| 582 | } |
| 583 | |
| 584 | /* --- Handle `$(...)'-style command substitution --- */ |
| 585 | |
| 586 | else if (ch == '(') { |
| 587 | if ((e = cmdsubst(t, fp, d, f & ~EVF_BACKTICK)) != ENV_OK) |
| 588 | return (e); |
| 589 | } |
| 590 | |
| 591 | /* --- No other `$...' tricks implemented yet --- * |
| 592 | * |
| 593 | * Other ideas: `$((...))' arithmetic. |
| 594 | */ |
| 595 | |
| 596 | else |
| 597 | return (ENV_SUBST); |
| 598 | continue; |
| 599 | } |
| 600 | |
| 601 | /* --- At this point, anything else double-quoted is munched --- */ |
| 602 | |
| 603 | if (qt == Q_DOUBLE) { |
| 604 | DPUTC(d, ch); |
| 605 | continue; |
| 606 | } |
| 607 | |
| 608 | /* --- Some characters just aren't allowed unquoted --- * |
| 609 | * |
| 610 | * They're not an error; they just mean I should stop parsing. They're |
| 611 | * probably interesting to the next level up. |
| 612 | */ |
| 613 | |
| 614 | switch (ch) { |
| 615 | case '(': case ')': |
| 616 | case '{': case '}': |
| 617 | case ';': |
| 618 | ungetc(ch, fp); |
| 619 | goto done; |
| 620 | case '`': |
| 621 | if (f & EVF_BACKTICK) { |
| 622 | ungetc(ch, fp); |
| 623 | goto done; |
| 624 | } |
| 625 | break; |
| 626 | } |
| 627 | |
| 628 | /* --- Whitespace characters --- * |
| 629 | * |
| 630 | * I might snarf them myself anyway, according to flags. Or I might |
| 631 | * stop, and skip any following whitespace |
| 632 | */ |
| 633 | |
| 634 | if (isspace((unsigned char)ch) && (f & EVF_INCSPC) == 0) { |
| 635 | do |
| 636 | ch = getc(fp); |
| 637 | while (ch != EOF && isspace((unsigned char)ch)); |
| 638 | ungetc(ch, fp); |
| 639 | break; |
| 640 | } |
| 641 | |
| 642 | /* --- Get a new character and go around again --- */ |
| 643 | |
| 644 | DPUTC(d, ch); |
| 645 | } |
| 646 | |
| 647 | /* --- Tidying --- */ |
| 648 | |
| 649 | done: |
| 650 | DPUTZ(d); |
| 651 | return (qt == Q_NONE ? ENV_OK : ENV_QUOTE); |
| 652 | } |
| 653 | |
| 654 | /* --- @env_read@ --- * |
| 655 | * |
| 656 | * Arguments: @sym_table *t@ = pointer to symbol table |
| 657 | * @FILE *fp@ = file handle to read |
| 658 | * @unsigned f@ = various flags |
| 659 | * |
| 660 | * Returns: Zero if OK, @EOF@ for end-of-file, or error code. |
| 661 | * |
| 662 | * Use: Reads the environment assignment statements in the file. |
| 663 | */ |
| 664 | |
| 665 | int env_read(sym_table *t, FILE *fp, unsigned f) |
| 666 | { |
| 667 | dstr n = DSTR_INIT, v = DSTR_INIT; |
| 668 | int e = ENV_OK, ch; |
| 669 | |
| 670 | for (;;) { |
| 671 | ch = peek(fp); |
| 672 | |
| 673 | if (ch == ':') { |
| 674 | getc(fp); |
| 675 | peek(fp); |
| 676 | if ((e = env_value(t, fp, &v, f)) != ENV_OK) |
| 677 | goto done; |
| 678 | } |
| 679 | |
| 680 | else if (ch == '#') |
| 681 | do ch = getc(fp); while (ch != EOF && ch != '\n'); |
| 682 | |
| 683 | else if (peek(fp) == '}' || |
| 684 | (e = env_var(t, fp, &n)) != ENV_OK) |
| 685 | goto done; |
| 686 | |
| 687 | else if (strcmp(n.buf, "include") == 0) { |
| 688 | peek(fp); |
| 689 | if ((e = env_value(t, fp, &v, f)) != ENV_OK) |
| 690 | goto done; |
| 691 | if (!(f & EVF_SKIP)) |
| 692 | env_file(t, v.buf); |
| 693 | } |
| 694 | |
| 695 | else if (strcmp(n.buf, "arch") == 0) { |
| 696 | peek(fp); |
| 697 | if ((e = env_value(t, fp, &v, f)) != ENV_OK) |
| 698 | goto done; |
| 699 | if (peek(fp) != '{') { |
| 700 | e = ENV_BRACE; |
| 701 | goto done; |
| 702 | } |
| 703 | getc(fp); |
| 704 | e = env_read(t, fp, strcmp(v.buf, ARCH) ? f | EVF_SKIP : f); |
| 705 | if (e != ENV_OK) |
| 706 | goto done; |
| 707 | if (getc(fp) != '}') { |
| 708 | e = ENV_BRACE; |
| 709 | goto done; |
| 710 | } |
| 711 | } |
| 712 | |
| 713 | else if (strcmp(n.buf, "unset") == 0) { |
| 714 | peek(fp); |
| 715 | if ((e = env_var(t, fp, &v)) != ENV_OK) |
| 716 | goto done; |
| 717 | env_put(t, v.buf, 0); |
| 718 | } |
| 719 | |
| 720 | else { |
| 721 | if (strcmp(n.buf, "set") == 0) { |
| 722 | DRESET(&n); |
| 723 | peek(fp); |
| 724 | if ((e = env_var(t, fp, &n)) != ENV_OK) |
| 725 | goto done; |
| 726 | } |
| 727 | if (peek(fp) == '=') { |
| 728 | getc(fp); |
| 729 | peek(fp); |
| 730 | } |
| 731 | if ((e = env_value(t, fp, &v, f)) != ENV_OK) |
| 732 | goto done; |
| 733 | |
| 734 | if (!(f & EVF_SKIP)) |
| 735 | env_put(t, n.buf, v.buf); |
| 736 | } |
| 737 | |
| 738 | if (peek(fp) == ';') |
| 739 | getc(fp); |
| 740 | DRESET(&n); |
| 741 | DRESET(&v); |
| 742 | } |
| 743 | |
| 744 | done: |
| 745 | dstr_destroy(&n); |
| 746 | dstr_destroy(&v); |
| 747 | return (e); |
| 748 | } |
| 749 | |
| 750 | /* --- @env_file@ --- * |
| 751 | * |
| 752 | * Arguments: @sym_table *t@ = pointer to symbol table |
| 753 | * @const char *name@ = pointer to filename |
| 754 | * |
| 755 | * Returns: Zero if OK, or an error code. |
| 756 | * |
| 757 | * Use: Reads a named file of environment assignments. |
| 758 | */ |
| 759 | |
| 760 | int env_file(sym_table *t, const char *name) |
| 761 | { |
| 762 | FILE *fp; |
| 763 | int e; |
| 764 | |
| 765 | if ((fp = fopen(name, "r")) == 0) |
| 766 | return (ENV_SYSTEM); |
| 767 | e = env_read(t, fp, 0); |
| 768 | fclose(fp); |
| 769 | if (e == ENV_EOF) |
| 770 | e = ENV_OK; |
| 771 | else if (e == ENV_OK) |
| 772 | e = ENV_BRACE; |
| 773 | return (e); |
| 774 | } |
| 775 | |
| 776 | /*----- That's all, folks -------------------------------------------------*/ |