bin/ksh/var.c

   1 /*      $OpenBSD: var.c,v 1.70 2018/06/18 21:46:05 millert Exp $        */
   2
   3 #include <sys/stat.h>
   4 #include <sys/time.h>
   5
   6 #include <ctype.h>
   7 #include <errno.h>
   8 #include <inttypes.h>
   9 #include <limits.h>
  10 #include <stdlib.h>
  11 #include <string.h>
  12 #include <time.h>
  13 #include <unistd.h>
  14 #ifndef SMALL
  15 # include <term.h>
  16 # include <curses.h>
  17 #endif
  18
  19 #include "sh.h"
  20
  21 /*
  22  * Variables
  23  *
  24  * WARNING: unreadable code, needs a rewrite
  25  *
  26  * if (flag&INTEGER), val.i contains integer value, and type contains base.
  27  * otherwise, (val.s + type) contains string value.
  28  * if (flag&EXPORT), val.s contains "name=value" for E-Z exporting.
  29  */
  30 static  struct tbl vtemp;
  31 static  struct table specials;
  32 static char     *formatstr(struct tbl *, const char *);
  33 static void     export(struct tbl *, const char *);
  34 static int      special(const char *);
  35 static void     unspecial(const char *);
  36 static void     getspec(struct tbl *);
  37 static void     setspec(struct tbl *);
  38 static void     unsetspec(struct tbl *);
  39 static struct tbl *arraysearch(struct tbl *, int);
  40
  41 /*
  42  * create a new block for function calls and simple commands
  43  * assume caller has allocated and set up genv->loc
  44  */
  45 void
  46 newblock(void)
  47 {
  48         struct block *l;
  49         static char *const empty[] = {null};
  50
  51         l = alloc(sizeof(struct block), ATEMP);
  52         l->flags = 0;
  53         ainit(&l->area); /* todo: could use genv->area (l->area => l->areap) */
  54         if (!genv->loc) {
  55                 l->argc = 0;
  56                 l->argv = (char **) empty;
  57         } else {
  58                 l->argc = genv->loc->argc;
  59                 l->argv = genv->loc->argv;
  60         }
  61         l->exit = l->error = NULL;
  62         ktinit(&l->vars, &l->area, 0);
  63         ktinit(&l->funs, &l->area, 0);
  64         l->next = genv->loc;
  65         genv->loc = l;
  66 }
  67
  68 /*
  69  * pop a block handling special variables
  70  */
  71 void
  72 popblock(void)
  73 {
  74         struct block *l = genv->loc;
  75         struct tbl *vp, **vpp = l->vars.tbls, *vq;
  76         int i;
  77
  78         genv->loc = l->next;    /* pop block */
  79         for (i = l->vars.size; --i >= 0; )
  80                 if ((vp = *vpp++) != NULL && (vp->flag&SPECIAL)) {
  81                         if ((vq = global(vp->name))->flag & ISSET)
  82                                 setspec(vq);
  83                         else
  84                                 unsetspec(vq);
  85                 }
  86         if (l->flags & BF_DOGETOPTS)
  87                 user_opt = l->getopts_state;
  88         afreeall(&l->area);
  89         afree(l, ATEMP);
  90 }
  91
  92 /* called by main() to initialize variable data structures */
  93 void
  94 initvar(void)
  95 {
  96         static const struct {
  97                 const char *name;
  98                 int v;
  99         } names[] = {
 100                 { "COLUMNS",            V_COLUMNS },
 101                 { "IFS",                V_IFS },
 102                 { "OPTIND",             V_OPTIND },
 103                 { "PATH",               V_PATH },
 104                 { "POSIXLY_CORRECT",    V_POSIXLY_CORRECT },
 105                 { "TMPDIR",             V_TMPDIR },
 106                 { "HISTCONTROL",        V_HISTCONTROL },
 107                 { "HISTFILE",           V_HISTFILE },
 108                 { "HISTSIZE",           V_HISTSIZE },
 109                 { "EDITOR",             V_EDITOR },
 110                 { "VISUAL",             V_VISUAL },
 111                 { "MAIL",               V_MAIL },
 112                 { "MAILCHECK",          V_MAILCHECK },
 113                 { "MAILPATH",           V_MAILPATH },
 114                 { "RANDOM",             V_RANDOM },
 115                 { "SECONDS",            V_SECONDS },
 116                 { "TMOUT",              V_TMOUT },
 117                 { "LINENO",             V_LINENO },
 118                 { "TERM",               V_TERM },
 119                 { NULL, 0 }
 120         };
 121         int i;
 122         struct tbl *tp;
 123
 124         ktinit(&specials, APERM, 32); /* must be 2^n (currently 19 specials) */
 125         for (i = 0; names[i].name; i++) {
 126                 tp = ktenter(&specials, names[i].name, hash(names[i].name));
 127                 tp->flag = DEFINED|ISSET;
 128                 tp->type = names[i].v;
 129         }
 130 }
 131
 132 /* Used to calculate an array index for global()/local().  Sets *arrayp to
 133  * non-zero if this is an array, sets *valp to the array index, returns
 134  * the basename of the array.
 135  */
 136 static const char *
 137 array_index_calc(const char *n, bool *arrayp, int *valp)
 138 {
 139         const char *p;
 140         int len;
 141
 142         *arrayp = false;
 143         p = skip_varname(n, false);
 144         if (p != n && *p == '[' && (len = array_ref_len(p))) {
 145                 char *sub, *tmp;
 146                 int64_t rval;
 147
 148                 /* Calculate the value of the subscript */
 149                 *arrayp = true;
 150                 tmp = str_nsave(p+1, len-2, ATEMP);
 151                 sub = substitute(tmp, 0);
 152                 afree(tmp, ATEMP);
 153                 n = str_nsave(n, p - n, ATEMP);
 154                 evaluate(sub, &rval, KSH_UNWIND_ERROR, true);
 155                 if (rval < 0 || rval > INT_MAX)
 156                         errorf("%s: subscript %" PRIi64 " out of range",
 157                             n, rval);
 158                 *valp = rval;
 159                 afree(sub, ATEMP);
 160         }
 161         return n;
 162 }
 163
 164 /*
 165  * Search for variable, if not found create globally.
 166  */
 167 struct tbl *
 168 global(const char *n)
 169 {
 170         struct block *l = genv->loc;
 171         struct tbl *vp;
 172         long     num;
 173         int c;
 174         unsigned int h;
 175         bool     array;
 176         int      val;
 177
 178         /* Check to see if this is an array */
 179         n = array_index_calc(n, &array, &val);
 180         h = hash(n);
 181         c = (unsigned char)n[0];
 182         if (!letter(c)) {
 183                 if (array)
 184                         errorf("bad substitution");
 185                 vp = &vtemp;
 186                 vp->flag = DEFINED;
 187                 vp->type = 0;
 188                 vp->areap = ATEMP;
 189                 *vp->name = c;
 190                 if (digit(c)) {
 191                         errno = 0;
 192                         num = strtol(n, NULL, 10);
 193                         if (errno == 0 && num <= l->argc)
 194                                 /* setstr can't fail here */
 195                                 setstr(vp, l->argv[num], KSH_RETURN_ERROR);
 196                         vp->flag |= RDONLY;
 197                         return vp;
 198                 }
 199                 vp->flag |= RDONLY;
 200                 if (n[1] != '\0')
 201                         return vp;
 202                 vp->flag |= ISSET|INTEGER;
 203                 switch (c) {
 204                 case '$':
 205                         vp->val.i = kshpid;
 206                         break;
 207                 case '!':
 208                         /* If no job, expand to nothing */
 209                         if ((vp->val.i = j_async()) == 0)
 210                                 vp->flag &= ~(ISSET|INTEGER);
 211                         break;
 212                 case '?':
 213                         vp->val.i = exstat;
 214                         break;
 215                 case '#':
 216                         vp->val.i = l->argc;
 217                         break;
 218                 case '-':
 219                         vp->flag &= ~INTEGER;
 220                         vp->val.s = getoptions();
 221                         break;
 222                 default:
 223                         vp->flag &= ~(ISSET|INTEGER);
 224                 }
 225                 return vp;
 226         }
 227         for (l = genv->loc; ; l = l->next) {
 228                 vp = ktsearch(&l->vars, n, h);
 229                 if (vp != NULL) {
 230                         if (array)
 231                                 return arraysearch(vp, val);
 232                         else
 233                                 return vp;
 234                 }
 235                 if (l->next == NULL)
 236                         break;
 237         }
 238         vp = ktenter(&l->vars, n, h);
 239         if (array)
 240                 vp = arraysearch(vp, val);
 241         vp->flag |= DEFINED;
 242         if (special(n))
 243                 vp->flag |= SPECIAL;
 244         return vp;
 245 }
 246
 247 /*
 248  * Search for local variable, if not found create locally.
 249  */
 250 struct tbl *
 251 local(const char *n, bool copy)
 252 {
 253         struct block *l = genv->loc;
 254         struct tbl *vp;
 255         unsigned int h;
 256         bool     array;
 257         int      val;
 258
 259         /* Check to see if this is an array */
 260         n = array_index_calc(n, &array, &val);
 261         h = hash(n);
 262         if (!letter(*n)) {
 263                 vp = &vtemp;
 264                 vp->flag = DEFINED|RDONLY;
 265                 vp->type = 0;
 266                 vp->areap = ATEMP;
 267                 return vp;
 268         }
 269         vp = ktenter(&l->vars, n, h);
 270         if (copy && !(vp->flag & DEFINED)) {
 271                 struct block *ll = l;
 272                 struct tbl *vq = NULL;
 273
 274                 while ((ll = ll->next) && !(vq = ktsearch(&ll->vars, n, h)))
 275                         ;
 276                 if (vq) {
 277                         vp->flag |= vq->flag &
 278                             (EXPORT | INTEGER | RDONLY | LJUST | RJUST |
 279                             ZEROFIL | LCASEV | UCASEV_AL | INT_U | INT_L);
 280                         if (vq->flag & INTEGER)
 281                                 vp->type = vq->type;
 282                         vp->u2.field = vq->u2.field;
 283                 }
 284         }
 285         if (array)
 286                 vp = arraysearch(vp, val);
 287         vp->flag |= DEFINED;
 288         if (special(n))
 289                 vp->flag |= SPECIAL;
 290         return vp;
 291 }
 292
 293 /* get variable string value */
 294 char *
 295 str_val(struct tbl *vp)
 296 {
 297         char *s;
 298
 299         if ((vp->flag&SPECIAL))
 300                 getspec(vp);
 301         if (!(vp->flag&ISSET))
 302                 s = null;               /* special to dollar() */
 303         else if (!(vp->flag&INTEGER))   /* string source */
 304                 s = vp->val.s + vp->type;
 305         else {                          /* integer source */
 306                 /* worst case number length is when base=2, so use
 307                  * minus base # number BITS(int64_t) NUL */
 308                 char strbuf[1 + 2 + 1 + BITS(int64_t) + 1];
 309                 const char *digits = (vp->flag & UCASEV_AL) ?
 310                     "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ" :
 311                     "0123456789abcdefghijklmnopqrstuvwxyz";
 312                 uint64_t n;
 313                 unsigned int base;
 314
 315                 s = strbuf + sizeof(strbuf);
 316                 if (vp->flag & INT_U)
 317                         n = (uint64_t) vp->val.i;
 318                 else
 319                         n = (vp->val.i < 0) ? -vp->val.i : vp->val.i;
 320                 base = (vp->type == 0) ? 10 : vp->type;
 321                 if (base < 2 || base > strlen(digits))
 322                         base = 10;
 323
 324                 *--s = '\0';
 325                 do {
 326                         *--s = digits[n % base];
 327                         n /= base;
 328                 } while (n != 0);
 329                 if (base != 10) {
 330                         *--s = '#';
 331                         *--s = digits[base % 10];
 332                         if (base >= 10)
 333                                 *--s = digits[base / 10];
 334                 }
 335                 if (!(vp->flag & INT_U) && vp->val.i < 0)
 336                         *--s = '-';
 337                 if (vp->flag & (RJUST|LJUST)) /* case already dealt with */
 338                         s = formatstr(vp, s);
 339                 else
 340                         s = str_save(s, ATEMP);
 341         }
 342         return s;
 343 }
 344
 345 /* get variable integer value, with error checking */
 346 int64_t
 347 intval(struct tbl *vp)
 348 {
 349         int64_t num;
 350         int base;
 351
 352         base = getint(vp, &num, false);
 353         if (base == -1)
 354                 /* XXX check calls - is error here ok by POSIX? */
 355                 errorf("%s: bad number", str_val(vp));
 356         return num;
 357 }
 358
 359 /* set variable to string value */
 360 int
 361 setstr(struct tbl *vq, const char *s, int error_ok)
 362 {
 363         const char *fs = NULL;
 364         int no_ro_check = error_ok & KSH_IGNORE_RDONLY;
 365         error_ok &= ~KSH_IGNORE_RDONLY;
 366         if ((vq->flag & RDONLY) && !no_ro_check) {
 367                 warningf(true, "%s: is read only", vq->name);
 368                 if (!error_ok)
 369                         errorf(NULL);
 370                 return 0;
 371         }
 372         if (!(vq->flag&INTEGER)) { /* string dest */
 373                 if ((vq->flag&ALLOC)) {
 374                         /* debugging */
 375                         if (s >= vq->val.s &&
 376                             s <= vq->val.s + strlen(vq->val.s))
 377                                 internal_errorf("%s: %s=%s: assigning to self",
 378                                     __func__, vq->name, s);
 379                         afree(vq->val.s, vq->areap);
 380                 }
 381                 vq->flag &= ~(ISSET|ALLOC);
 382                 vq->type = 0;
 383                 if (s && (vq->flag & (UCASEV_AL|LCASEV|LJUST|RJUST)))
 384                         fs = s = formatstr(vq, s);
 385                 if ((vq->flag&EXPORT))
 386                         export(vq, s);
 387                 else {
 388                         vq->val.s = str_save(s, vq->areap);
 389                         vq->flag |= ALLOC;
 390                 }
 391         } else {                /* integer dest */
 392                 if (!v_evaluate(vq, s, error_ok, true))
 393                         return 0;
 394         }
 395         vq->flag |= ISSET;
 396         if ((vq->flag&SPECIAL))
 397                 setspec(vq);
 398         afree((void *)fs, ATEMP);
 399         return 1;
 400 }
 401
 402 /* set variable to integer */
 403 void
 404 setint(struct tbl *vq, int64_t n)
 405 {
 406         if (!(vq->flag&INTEGER)) {
 407                 struct tbl *vp = &vtemp;
 408                 vp->flag = (ISSET|INTEGER);
 409                 vp->type = 0;
 410                 vp->areap = ATEMP;
 411                 vp->val.i = n;
 412                 /* setstr can't fail here */
 413                 setstr(vq, str_val(vp), KSH_RETURN_ERROR);
 414         } else
 415                 vq->val.i = n;
 416         vq->flag |= ISSET;
 417         if ((vq->flag&SPECIAL))
 418                 setspec(vq);
 419 }
 420
 421 int
 422 getint(struct tbl *vp, int64_t *nump, bool arith)
 423 {
 424         char *s;
 425         int c;
 426         int base, neg;
 427         int have_base = 0;
 428         int64_t num;
 429
 430         if (vp->flag&SPECIAL)
 431                 getspec(vp);
 432         /* XXX is it possible for ISSET to be set and val.s to be 0? */
 433         if (!(vp->flag&ISSET) || (!(vp->flag&INTEGER) && vp->val.s == NULL))
 434                 return -1;
 435         if (vp->flag&INTEGER) {
 436                 *nump = vp->val.i;
 437                 return vp->type;
 438         }
 439         s = vp->val.s + vp->type;
 440         if (s == NULL)  /* redundant given initial test */
 441                 s = null;
 442         base = 10;
 443         num = 0;
 444         neg = 0;
 445         if (arith && *s == '0' && *(s+1)) {
 446                 s++;
 447                 if (*s == 'x' || *s == 'X') {
 448                         s++;
 449                         base = 16;
 450                 } else if (vp->flag & ZEROFIL) {
 451                         while (*s == '0')
 452                                 s++;
 453                 } else
 454                         base = 8;
 455                 have_base++;
 456         }
 457         for (c = (unsigned char)*s++; c ; c = (unsigned char)*s++) {
 458                 if (c == '-') {
 459                         neg++;
 460                 } else if (c == '#') {
 461                         base = (int) num;
 462                         if (have_base || base < 2 || base > 36)
 463                                 return -1;
 464                         num = 0;
 465                         have_base = 1;
 466                 } else if (letnum(c)) {
 467                         if (isdigit(c))
 468                                 c -= '0';
 469                         else if (islower(c))
 470                                 c -= 'a' - 10; /* todo: assumes ascii */
 471                         else if (isupper(c))
 472                                 c -= 'A' - 10; /* todo: assumes ascii */
 473                         else
 474                                 c = -1; /* _: force error */
 475                         if (c < 0 || c >= base)
 476                                 return -1;
 477                         num = num * base + c;
 478                 } else
 479                         return -1;
 480         }
 481         if (neg)
 482                 num = -num;
 483         *nump = num;
 484         return base;
 485 }
 486
 487 /* convert variable vq to integer variable, setting its value from vp
 488  * (vq and vp may be the same)
 489  */
 490 struct tbl *
 491 setint_v(struct tbl *vq, struct tbl *vp, bool arith)
 492 {
 493         int base;
 494         int64_t num;
 495
 496         if ((base = getint(vp, &num, arith)) == -1)
 497                 return NULL;
 498         if (!(vq->flag & INTEGER) && (vq->flag & ALLOC)) {
 499                 vq->flag &= ~ALLOC;
 500                 afree(vq->val.s, vq->areap);
 501         }
 502         vq->val.i = num;
 503         if (vq->type == 0) /* default base */
 504                 vq->type = base;
 505         vq->flag |= ISSET|INTEGER;
 506         if (vq->flag&SPECIAL)
 507                 setspec(vq);
 508         return vq;
 509 }
 510
 511 static char *
 512 formatstr(struct tbl *vp, const char *s)
 513 {
 514         int olen, nlen;
 515         char *p, *q;
 516
 517         olen = strlen(s);
 518
 519         if (vp->flag & (RJUST|LJUST)) {
 520                 if (!vp->u2.field)      /* default field width */
 521                         vp->u2.field = olen;
 522                 nlen = vp->u2.field;
 523         } else
 524                 nlen = olen;
 525
 526         p = alloc(nlen + 1, ATEMP);
 527         if (vp->flag & (RJUST|LJUST)) {
 528                 int slen;
 529
 530                 if (vp->flag & RJUST) {
 531                         const char *r = s + olen;
 532                         /* strip trailing spaces (at&t ksh uses r[-1] == ' ') */
 533                         while (r > s && isspace((unsigned char)r[-1]))
 534                                 --r;
 535                         slen = r - s;
 536                         if (slen > vp->u2.field) {
 537                                 s += slen - vp->u2.field;
 538                                 slen = vp->u2.field;
 539                         }
 540                         shf_snprintf(p, nlen + 1,
 541                                 ((vp->flag & ZEROFIL) && digit(*s)) ?
 542                                           "%0*s%.*s" : "%*s%.*s",
 543                                 vp->u2.field - slen, null, slen, s);
 544                 } else {
 545                         /* strip leading spaces/zeros */
 546                         while (isspace((unsigned char)*s))
 547                                 s++;
 548                         if (vp->flag & ZEROFIL)
 549                                 while (*s == '0')
 550                                         s++;
 551                         shf_snprintf(p, nlen + 1, "%-*.*s",
 552                                 vp->u2.field, vp->u2.field, s);
 553                 }
 554         } else
 555                 memcpy(p, s, olen + 1);
 556
 557         if (vp->flag & UCASEV_AL) {
 558                 for (q = p; *q; q++)
 559                         if (islower((unsigned char)*q))
 560                                 *q = toupper((unsigned char)*q);
 561         } else if (vp->flag & LCASEV) {
 562                 for (q = p; *q; q++)
 563                         if (isupper((unsigned char)*q))
 564                                 *q = tolower((unsigned char)*q);
 565         }
 566
 567         return p;
 568 }
 569
 570 /*
 571  * make vp->val.s be "name=value" for quick exporting.
 572  */
 573 static void
 574 export(struct tbl *vp, const char *val)
 575 {
 576         char *xp;
 577         char *op = (vp->flag&ALLOC) ? vp->val.s : NULL;
 578         int namelen = strlen(vp->name);
 579         int vallen = strlen(val) + 1;
 580
 581         vp->flag |= ALLOC;
 582         xp = alloc(namelen + 1 + vallen, vp->areap);
 583         memcpy(vp->val.s = xp, vp->name, namelen);
 584         xp += namelen;
 585         *xp++ = '=';
 586         vp->type = xp - vp->val.s; /* offset to value */
 587         memcpy(xp, val, vallen);
 588         afree(op, vp->areap);
 589 }
 590
 591 /*
 592  * lookup variable (according to (set&LOCAL)),
 593  * set its attributes (INTEGER, RDONLY, EXPORT, TRACE, LJUST, RJUST, ZEROFIL,
 594  * LCASEV, UCASEV_AL), and optionally set its value if an assignment.
 595  */
 596 struct tbl *
 597 typeset(const char *var, int set, int clr, int field, int base)
 598 {
 599         struct tbl *vp;
 600         struct tbl *vpbase, *t;
 601         char *tvar;
 602         const char *val;
 603
 604         /* check for valid variable name, search for value */
 605         val = skip_varname(var, false);
 606         if (val == var)
 607                 return NULL;
 608         if (*val == '[') {
 609                 int len;
 610
 611                 len = array_ref_len(val);
 612                 if (len == 0)
 613                         return NULL;
 614                 /* IMPORT is only used when the shell starts up and is
 615                  * setting up its environment.  Allow only simple array
 616                  * references at this time since parameter/command substitution
 617                  * is preformed on the [expression], which would be a major
 618                  * security hole.
 619                  */
 620                 if (set & IMPORT) {
 621                         int i;
 622                         for (i = 1; i < len - 1; i++)
 623                                 if (!digit(val[i]))
 624                                         return NULL;
 625                 }
 626                 val += len;
 627         }
 628         if (*val == '=')
 629                 tvar = str_nsave(var, val++ - var, ATEMP);
 630         else {
 631                 /* Importing from original environment: must have an = */
 632                 if (set & IMPORT)
 633                         return NULL;
 634                 tvar = (char *) var;
 635                 val = NULL;
 636         }
 637
 638         /* Prevent typeset from creating a local PATH/ENV/SHELL */
 639         if (Flag(FRESTRICTED) && (strcmp(tvar, "PATH") == 0 ||
 640             strcmp(tvar, "ENV") == 0 || strcmp(tvar, "SHELL") == 0))
 641                 errorf("%s: restricted", tvar);
 642
 643         vp = (set&LOCAL) ? local(tvar, (set & LOCAL_COPY) ? true : false) :
 644             global(tvar);
 645         set &= ~(LOCAL|LOCAL_COPY);
 646
 647         vpbase = (vp->flag & ARRAY) ? global(arrayname(var)) : vp;
 648
 649         /* only allow export flag to be set.  at&t ksh allows any attribute to
 650          * be changed, which means it can be truncated or modified
 651          * (-L/-R/-Z/-i).
 652          */
 653         if ((vpbase->flag&RDONLY) &&
 654             (val || clr || (set & ~EXPORT)))
 655                 /* XXX check calls - is error here ok by POSIX? */
 656                 errorf("%s: is read only", tvar);
 657         if (val)
 658                 afree(tvar, ATEMP);
 659
 660         /* most calls are with set/clr == 0 */
 661         if (set | clr) {
 662                 int ok = 1;
 663                 /* XXX if x[0] isn't set, there will be problems: need to have
 664                  * one copy of attributes for arrays...
 665                  */
 666                 for (t = vpbase; t; t = t->u.array) {
 667                         int fake_assign;
 668                         int error_ok = KSH_RETURN_ERROR;
 669                         char *s = NULL;
 670                         char *free_me = NULL;
 671
 672                         fake_assign = (t->flag & ISSET) && (!val || t != vp) &&
 673                             ((set & (UCASEV_AL|LCASEV|LJUST|RJUST|ZEROFIL)) ||
 674                             ((t->flag & INTEGER) && (clr & INTEGER)) ||
 675                             (!(t->flag & INTEGER) && (set & INTEGER)));
 676                         if (fake_assign) {
 677                                 if (t->flag & INTEGER) {
 678                                         s = str_val(t);
 679                                         free_me = NULL;
 680                                 } else {
 681                                         s = t->val.s + t->type;
 682                                         free_me = (t->flag & ALLOC) ? t->val.s :
 683                                             NULL;
 684                                 }
 685                                 t->flag &= ~ALLOC;
 686                         }
 687                         if (!(t->flag & INTEGER) && (set & INTEGER)) {
 688                                 t->type = 0;
 689                                 t->flag &= ~ALLOC;
 690                         }
 691                         if (!(t->flag & RDONLY) && (set & RDONLY)) {
 692                                 /* allow var to be initialized read-only */
 693                                 error_ok |= KSH_IGNORE_RDONLY;
 694                         }
 695                         t->flag = (t->flag | set) & ~clr;
 696                         /* Don't change base if assignment is to be done,
 697                          * in case assignment fails.
 698                          */
 699                         if ((set & INTEGER) && base > 0 && (!val || t != vp))
 700                                 t->type = base;
 701                         if (set & (LJUST|RJUST|ZEROFIL))
 702                                 t->u2.field = field;
 703                         if (fake_assign) {
 704                                 if (!setstr(t, s, error_ok)) {
 705                                         /* Somewhat arbitrary action here:
 706                                          * zap contents of variable, but keep
 707                                          * the flag settings.
 708                                          */
 709                                         ok = 0;
 710                                         if (t->flag & INTEGER)
 711                                                 t->flag &= ~ISSET;
 712                                         else {
 713                                                 if (t->flag & ALLOC)
 714                                                         afree(t->val.s, t->areap);
 715                                                 t->flag &= ~(ISSET|ALLOC);
 716                                                 t->type = 0;
 717                                         }
 718                                 }
 719                                 afree(free_me, t->areap);
 720                         }
 721                 }
 722                 if (!ok)
 723                     errorf(NULL);
 724         }
 725
 726         if (val != NULL) {
 727                 if (vp->flag&INTEGER) {
 728                         /* do not zero base before assignment */
 729                         setstr(vp, val, KSH_UNWIND_ERROR | KSH_IGNORE_RDONLY);
 730                         /* Done after assignment to override default */
 731                         if (base > 0)
 732                                 vp->type = base;
 733                 } else
 734                         /* setstr can't fail (readonly check already done) */
 735                         setstr(vp, val, KSH_RETURN_ERROR | KSH_IGNORE_RDONLY);
 736         }
 737
 738         /* only x[0] is ever exported, so use vpbase */
 739         if ((vpbase->flag&EXPORT) && !(vpbase->flag&INTEGER) &&
 740             vpbase->type == 0)
 741                 export(vpbase, (vpbase->flag&ISSET) ? vpbase->val.s : null);
 742
 743         return vp;
 744 }
 745
 746 /* Unset a variable.  array_ref is set if there was an array reference in
 747  * the name lookup (eg, x[2]).
 748  */
 749 void
 750 unset(struct tbl *vp, int array_ref)
 751 {
 752         if (vp->flag & ALLOC)
 753                 afree(vp->val.s, vp->areap);
 754         if ((vp->flag & ARRAY) && !array_ref) {
 755                 struct tbl *a, *tmp;
 756
 757                 /* Free up entire array */
 758                 for (a = vp->u.array; a; ) {
 759                         tmp = a;
 760                         a = a->u.array;
 761                         if (tmp->flag & ALLOC)
 762                                 afree(tmp->val.s, tmp->areap);
 763                         afree(tmp, tmp->areap);
 764                 }
 765                 vp->u.array = NULL;
 766         }
 767         /* If foo[0] is being unset, the remainder of the array is kept... */
 768         vp->flag &= SPECIAL | (array_ref ? ARRAY|DEFINED : 0);
 769         if (vp->flag & SPECIAL)
 770                 unsetspec(vp);  /* responsible for `unspecial'ing var */
 771 }
 772
 773 /* return a pointer to the first char past a legal variable name (returns the
 774  * argument if there is no legal name, returns * a pointer to the terminating
 775  * null if whole string is legal).
 776  */
 777 char *
 778 skip_varname(const char *s, int aok)
 779 {
 780         int alen;
 781
 782         if (s && letter(*s)) {
 783                 while (*++s && letnum(*s))
 784                         ;
 785                 if (aok && *s == '[' && (alen = array_ref_len(s)))
 786                         s += alen;
 787         }
 788         return (char *) s;
 789 }
 790
 791 /* Return a pointer to the first character past any legal variable name.  */
 792 char *
 793 skip_wdvarname(const char *s,
 794     int aok)                            /* skip array de-reference? */
 795 {
 796         if (s[0] == CHAR && letter(s[1])) {
 797                 do {
 798                         s += 2;
 799                 } while (s[0] == CHAR && letnum(s[1]));
 800                 if (aok && s[0] == CHAR && s[1] == '[') {
 801                         /* skip possible array de-reference */
 802                         const char *p = s;
 803                         char c;
 804                         int depth = 0;
 805
 806                         while (1) {
 807                                 if (p[0] != CHAR)
 808                                         break;
 809                                 c = p[1];
 810                                 p += 2;
 811                                 if (c == '[')
 812                                         depth++;
 813                                 else if (c == ']' && --depth == 0) {
 814                                         s = p;
 815                                         break;
 816                                 }
 817                         }
 818                 }
 819         }
 820         return (char *) s;
 821 }
 822
 823 /* Check if coded string s is a variable name */
 824 int
 825 is_wdvarname(const char *s, int aok)
 826 {
 827         char *p = skip_wdvarname(s, aok);
 828
 829         return p != s && p[0] == EOS;
 830 }
 831
 832 /* Check if coded string s is a variable assignment */
 833 int
 834 is_wdvarassign(const char *s)
 835 {
 836         char *p = skip_wdvarname(s, true);
 837
 838         return p != s && p[0] == CHAR && p[1] == '=';
 839 }
 840
 841 /*
 842  * Make the exported environment from the exported names in the dictionary.
 843  */
 844 char **
 845 makenv(void)
 846 {
 847         struct block *l;
 848         XPtrV env;
 849         struct tbl *vp, **vpp;
 850         int i;
 851
 852         XPinit(env, 64);
 853         for (l = genv->loc; l != NULL; l = l->next)
 854                 for (vpp = l->vars.tbls, i = l->vars.size; --i >= 0; )
 855                         if ((vp = *vpp++) != NULL &&
 856                             (vp->flag&(ISSET|EXPORT)) == (ISSET|EXPORT)) {
 857                                 struct block *l2;
 858                                 struct tbl *vp2;
 859                                 unsigned int h = hash(vp->name);
 860
 861                                 /* unexport any redefined instances */
 862                                 for (l2 = l->next; l2 != NULL; l2 = l2->next) {
 863                                         vp2 = ktsearch(&l2->vars, vp->name, h);
 864                                         if (vp2 != NULL)
 865                                                 vp2->flag &= ~EXPORT;
 866                                 }
 867                                 if ((vp->flag&INTEGER)) {
 868                                         /* integer to string */
 869                                         char *val;
 870                                         val = str_val(vp);
 871                                         vp->flag &= ~(INTEGER|RDONLY);
 872                                         /* setstr can't fail here */
 873                                         setstr(vp, val, KSH_RETURN_ERROR);
 874                                 }
 875                                 XPput(env, vp->val.s);
 876                         }
 877         XPput(env, NULL);
 878         return (char **) XPclose(env);
 879 }
 880
 881 /*
 882  * Called after a fork in parent to bump the random number generator.
 883  * Done to ensure children will not get the same random number sequence
 884  * if the parent doesn't use $RANDOM.
 885  */
 886 void
 887 change_random(void)
 888 {
 889         rand();
 890 }
 891
 892 /*
 893  * handle special variables with side effects - PATH, SECONDS.
 894  */
 895
 896 /* Test if name is a special parameter */
 897 static int
 898 special(const char *name)
 899 {
 900         struct tbl *tp;
 901
 902         tp = ktsearch(&specials, name, hash(name));
 903         return tp && (tp->flag & ISSET) ? tp->type : V_NONE;
 904 }
 905
 906 /* Make a variable non-special */
 907 static void
 908 unspecial(const char *name)
 909 {
 910         struct tbl *tp;
 911
 912         tp = ktsearch(&specials, name, hash(name));
 913         if (tp)
 914                 ktdelete(tp);
 915 }
 916
 917 static  struct  timespec seconds;       /* time SECONDS last set */
 918 static  int     user_lineno;            /* what user set $LINENO to */
 919
 920 static void
 921 getspec(struct tbl *vp)
 922 {
 923         switch (special(vp->name)) {
 924         case V_SECONDS:
 925                 vp->flag &= ~SPECIAL;
 926                 /* On start up the value of SECONDS is used before seconds
 927                  * has been set - don't do anything in this case
 928                  * (see initcoms[] in main.c).
 929                  */
 930                 if (vp->flag & ISSET) {
 931                         struct timespec difference, now;
 932
 933                         clock_gettime(CLOCK_MONOTONIC, &now);
 934                         timespecsub(&now, &seconds, &difference);
 935                         setint(vp, (int64_t)difference.tv_sec);
 936                 }
 937                 vp->flag |= SPECIAL;
 938                 break;
 939         case V_RANDOM:
 940                 vp->flag &= ~SPECIAL;
 941                 setint(vp, (int64_t) (rand() & 0x7fff));
 942                 vp->flag |= SPECIAL;
 943                 break;
 944         case V_HISTSIZE:
 945                 vp->flag &= ~SPECIAL;
 946                 setint(vp, (int64_t) histsize);
 947                 vp->flag |= SPECIAL;
 948                 break;
 949         case V_OPTIND:
 950                 vp->flag &= ~SPECIAL;
 951                 setint(vp, (int64_t) user_opt.uoptind);
 952                 vp->flag |= SPECIAL;
 953                 break;
 954         case V_LINENO:
 955                 vp->flag &= ~SPECIAL;
 956                 setint(vp, (int64_t) current_lineno + user_lineno);
 957                 vp->flag |= SPECIAL;
 958                 break;
 959         }
 960 }
 961
 962 static void
 963 setspec(struct tbl *vp)
 964 {
 965         char *s;
 966
 967         switch (special(vp->name)) {
 968         case V_PATH:
 969                 afree(search_path, APERM);
 970                 search_path = str_save(str_val(vp), APERM);
 971                 flushcom(1);    /* clear tracked aliases */
 972                 break;
 973         case V_IFS:
 974                 setctypes(s = str_val(vp), C_IFS);
 975                 ifs0 = *s;
 976                 break;
 977         case V_OPTIND:
 978                 vp->flag &= ~SPECIAL;
 979                 getopts_reset((int) intval(vp));
 980                 vp->flag |= SPECIAL;
 981                 break;
 982         case V_POSIXLY_CORRECT:
 983                 change_flag(FPOSIX, OF_SPECIAL, 1);
 984                 break;
 985         case V_TMPDIR:
 986                 afree(tmpdir, APERM);
 987                 tmpdir = NULL;
 988                 /* Use tmpdir iff it is an absolute path, is writable and
 989                  * searchable and is a directory...
 990                  */
 991                 {
 992                         struct stat statb;
 993
 994                         s = str_val(vp);
 995                         if (s[0] == '/' && access(s, W_OK|X_OK) == 0 &&
 996                             stat(s, &statb) == 0 && S_ISDIR(statb.st_mode))
 997                                 tmpdir = str_save(s, APERM);
 998                 }
 999                 break;
1000         case V_HISTCONTROL:
1001                 sethistcontrol(str_val(vp));
1002                 break;
1003         case V_HISTSIZE:
1004                 vp->flag &= ~SPECIAL;
1005                 sethistsize((int) intval(vp));
1006                 vp->flag |= SPECIAL;
1007                 break;
1008         case V_HISTFILE:
1009                 sethistfile(str_val(vp));
1010                 break;
1011         case V_VISUAL:
1012                 set_editmode(str_val(vp));
1013                 break;
1014         case V_EDITOR:
1015                 if (!(global("VISUAL")->flag & ISSET))
1016                         set_editmode(str_val(vp));
1017                 break;
1018         case V_COLUMNS:
1019                 {
1020                         int64_t l;
1021
1022                         if (getint(vp, &l, false) == -1) {
1023                                 x_cols = MIN_COLS;
1024                                 break;
1025                         }
1026                         if (l <= MIN_COLS || l > INT_MAX)
1027                                 x_cols = MIN_COLS;
1028                         else
1029                                 x_cols = l;
1030                 }
1031                 break;
1032         case V_MAIL:
1033                 mbset(str_val(vp));
1034                 break;
1035         case V_MAILPATH:
1036                 mpset(str_val(vp));
1037                 break;
1038         case V_MAILCHECK:
1039                 vp->flag &= ~SPECIAL;
1040                 mcset(intval(vp));
1041                 vp->flag |= SPECIAL;
1042                 break;
1043         case V_RANDOM:
1044                 vp->flag &= ~SPECIAL;
1045                 srand_deterministic((unsigned int)intval(vp));
1046                 vp->flag |= SPECIAL;
1047                 break;
1048         case V_SECONDS:
1049                 vp->flag &= ~SPECIAL;
1050                 clock_gettime(CLOCK_MONOTONIC, &seconds);
1051                 seconds.tv_sec -= intval(vp);
1052                 vp->flag |= SPECIAL;
1053                 break;
1054         case V_TMOUT:
1055                 /* at&t ksh seems to do this (only listen if integer) */
1056                 if (vp->flag & INTEGER)
1057                         ksh_tmout = vp->val.i >= 0 ? vp->val.i : 0;
1058                 break;
1059         case V_LINENO:
1060                 vp->flag &= ~SPECIAL;
1061                 /* The -1 is because line numbering starts at 1. */
1062                 user_lineno = (unsigned int) intval(vp) - current_lineno - 1;
1063                 vp->flag |= SPECIAL;
1064                 break;
1065         case V_TERM:
1066 #ifndef SMALL
1067                 {
1068                         int ret;
1069
1070                         vp->flag &= ~SPECIAL;
1071                         if (setupterm(str_val(vp), shl_out->fd, &ret) == ERR)
1072                                 del_curterm(cur_term);
1073                         vp->flag |= SPECIAL;
1074                 }
1075 #endif
1076                 break;
1077         }
1078 }
1079
1080 static void
1081 unsetspec(struct tbl *vp)
1082 {
1083         switch (special(vp->name)) {
1084         case V_PATH:
1085                 afree(search_path, APERM);
1086                 search_path = str_save(def_path, APERM);
1087                 flushcom(1);    /* clear tracked aliases */
1088                 break;
1089         case V_IFS:
1090                 setctypes(" \t\n", C_IFS);
1091                 ifs0 = ' ';
1092                 break;
1093         case V_TMPDIR:
1094                 /* should not become unspecial */
1095                 afree(tmpdir, APERM);
1096                 tmpdir = NULL;
1097                 break;
1098         case V_MAIL:
1099                 mbset(NULL);
1100                 break;
1101         case V_MAILPATH:
1102                 mpset(NULL);
1103                 break;
1104         case V_HISTCONTROL:
1105                 sethistcontrol(NULL);
1106                 break;
1107         case V_LINENO:
1108         case V_MAILCHECK:       /* at&t ksh leaves previous value in place */
1109         case V_RANDOM:
1110         case V_SECONDS:
1111         case V_TMOUT:           /* at&t ksh leaves previous value in place */
1112                 unspecial(vp->name);
1113                 break;
1114
1115           /* at&t ksh man page says OPTIND, OPTARG and _ lose special meaning,
1116            * but OPTARG does not (still set by getopts) and _ is also still
1117            * set in various places.
1118            * Don't know what at&t does for:
1119            *            MAIL, MAILPATH, HISTSIZE, HISTFILE,
1120            * Unsetting these in at&t ksh does not loose the `specialness':
1121            *    no effect: IFS, COLUMNS, PATH, TMPDIR,
1122            *            VISUAL, EDITOR,
1123            * pdkshisms: no effect:
1124            *            POSIXLY_CORRECT (use set +o posix instead)
1125            */
1126         }
1127 }
1128
1129 /*
1130  * Search for (and possibly create) a table entry starting with
1131  * vp, indexed by val.
1132  */
1133 static struct tbl *
1134 arraysearch(struct tbl *vp, int val)
1135 {
1136         struct tbl *prev, *curr, *new;
1137         size_t namelen = strlen(vp->name) + 1;
1138
1139         vp->flag |= ARRAY|DEFINED;
1140         vp->index = 0;
1141         /* The table entry is always [0] */
1142         if (val == 0)
1143                 return vp;
1144         prev = vp;
1145         curr = vp->u.array;
1146         while (curr && curr->index < val) {
1147                 prev = curr;
1148                 curr = curr->u.array;
1149         }
1150         if (curr && curr->index == val) {
1151                 if (curr->flag&ISSET)
1152                         return curr;
1153                 else
1154                         new = curr;
1155         } else
1156                 new = alloc(sizeof(struct tbl) + namelen,
1157                     vp->areap);
1158         strlcpy(new->name, vp->name, namelen);
1159         new->flag = vp->flag & ~(ALLOC|DEFINED|ISSET|SPECIAL);
1160         new->type = vp->type;
1161         new->areap = vp->areap;
1162         new->u2.field = vp->u2.field;
1163         new->index = val;
1164         if (curr != new) {              /* not reusing old array entry */
1165                 prev->u.array = new;
1166                 new->u.array = curr;
1167         }
1168         return new;
1169 }
1170
1171 /* Return the length of an array reference (eg, [1+2]) - cp is assumed
1172  * to point to the open bracket.  Returns 0 if there is no matching closing
1173  * bracket.
1174  */
1175 int
1176 array_ref_len(const char *cp)
1177 {
1178         const char *s = cp;
1179         int c;
1180         int depth = 0;
1181
1182         while ((c = *s++) && (c != ']' || --depth))
1183                 if (c == '[')
1184                         depth++;
1185         if (!c)
1186                 return 0;
1187         return s - cp;
1188 }
1189
1190 /*
1191  * Make a copy of the base of an array name
1192  */
1193 char *
1194 arrayname(const char *str)
1195 {
1196         const char *p;
1197
1198         if ((p = strchr(str, '[')) == 0)
1199                 /* Shouldn't happen, but why worry? */
1200                 return (char *) str;
1201
1202         return str_nsave(str, p - str, ATEMP);
1203 }
1204
1205 /* Set (or overwrite, if !reset) the array variable var to the values in vals.
1206  */
1207 void
1208 set_array(const char *var, int reset, char **vals)
1209 {
1210         struct tbl *vp, *vq;
1211         int i;
1212
1213         /* to get local array, use "typeset foo; set -A foo" */
1214         vp = global(var);
1215
1216         /* Note: at&t ksh allows set -A but not set +A of a read-only var */
1217         if ((vp->flag&RDONLY))
1218                 errorf("%s: is read only", var);
1219         /* This code is quite non-optimal */
1220         if (reset > 0)
1221                 /* trash existing values and attributes */
1222                 unset(vp, 0);
1223         /* todo: would be nice for assignment to completely succeed or
1224          * completely fail.  Only really effects integer arrays:
1225          * evaluation of some of vals[] may fail...
1226          */
1227         for (i = 0; vals[i]; i++) {
1228                 vq = arraysearch(vp, i);
1229                 /* would be nice to deal with errors here... (see above) */
1230                 setstr(vq, vals[i], KSH_RETURN_ERROR);
1231         }
1232 }