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mksh/var.c

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/* $OpenBSD: var.c,v 1.30 2006/05/21 18:40:39 otto Exp $ */
#include "sh.h"
__RCSID("$MirOS: src/bin/mksh/var.c,v 1.44 2007/08/20 13:57:47 tg Exp $");
/*
* Variables
*
* WARNING: unreadable code, needs a rewrite
*
* if (flag&INTEGER), val.i contains integer value, and type contains base.
* otherwise, (val.s + type) contains string value.
* if (flag&EXPORT), val.s contains "name=value" for E-Z exporting.
*/
static struct tbl vtemp;
static struct table specials;
static char *formatstr(struct tbl *, const char *);
static void export(struct tbl *, const char *);
static int special(const char *);
static void unspecial(const char *);
static void getspec(struct tbl *);
static void setspec(struct tbl *);
static void unsetspec(struct tbl *);
static struct tbl *arraysearch(struct tbl *, int);
static int rnd_get(void);
static void rnd_set(long);
/*
* create a new block for function calls and simple commands
* assume caller has allocated and set up e->loc
*/
void
newblock(void)
{
struct block *l;
static const char *empty[] = { null };
l = (struct block *) alloc(sizeof(struct block), ATEMP);
l->flags = 0;
ainit(&l->area); /* todo: could use e->area (l->area => l->areap) */
if (!e->loc) {
l->argc = 0;
l->argv = empty;
} else {
l->argc = e->loc->argc;
l->argv = e->loc->argv;
}
l->exit = l->error = NULL;
ktinit(&l->vars, &l->area, 0);
ktinit(&l->funs, &l->area, 0);
l->next = e->loc;
e->loc = l;
}
/*
* pop a block handling special variables
*/
void
popblock(void)
{
struct block *l = e->loc;
struct tbl *vp, **vpp = l->vars.tbls, *vq;
int i;
e->loc = l->next; /* pop block */
for (i = l->vars.size; --i >= 0; )
if ((vp = *vpp++) != NULL && (vp->flag&SPECIAL)) {
if ((vq = global(vp->name))->flag & ISSET)
setspec(vq);
else
unsetspec(vq);
}
if (l->flags & BF_DOGETOPTS)
user_opt = l->getopts_state;
afreeall(&l->area);
afree(l, ATEMP);
}
/* called by main() to initialise variable data structures */
void
initvar(void)
{
static const struct {
const char *name;
int v;
} names[] = {
{ "COLUMNS", V_COLUMNS },
{ "IFS", V_IFS },
{ "OPTIND", V_OPTIND },
{ "PATH", V_PATH },
{ "TMPDIR", V_TMPDIR },
#if HAVE_PERSISTENT_HISTORY
{ "HISTFILE", V_HISTFILE },
#endif
{ "HISTSIZE", V_HISTSIZE },
{ "RANDOM", V_RANDOM },
{ "SECONDS", V_SECONDS },
{ "TMOUT", V_TMOUT },
{ "LINENO", V_LINENO },
{ NULL, 0 }
};
int i;
struct tbl *tp;
ktinit(&specials, APERM, 32); /* must be 2^n (currently 17 specials) */
for (i = 0; names[i].name; i++) {
tp = ktenter(&specials, names[i].name, hash(names[i].name));
tp->flag = DEFINED|ISSET;
tp->type = names[i].v;
}
}
/* Used to calculate an array index for global()/local(). Sets *arrayp to
* non-zero if this is an array, sets *valp to the array index, returns
* the basename of the array.
*/
static const char *
array_index_calc(const char *n, bool *arrayp, int *valp)
{
const char *p;
int len;
*arrayp = false;
p = skip_varname(n, false);
if (p != n && *p == '[' && (len = array_ref_len(p))) {
char *sub, *tmp;
long rval;
/* Calculate the value of the subscript */
*arrayp = true;
tmp = str_nsave(p+1, len-2, ATEMP);
sub = substitute(tmp, 0);
afree(tmp, ATEMP);
n = str_nsave(n, p - n, ATEMP);
evaluate(sub, &rval, KSH_UNWIND_ERROR, true);
if (rval < 0 || rval > 2147483647)
errorf("%s: subscript %ld out of range", n, rval);
*valp = rval;
afree(sub, ATEMP);
}
return n;
}
/*
* Search for variable, if not found create globally.
*/
struct tbl *
global(const char *n)
{
struct block *l = e->loc;
struct tbl *vp;
int c;
unsigned h;
bool array;
int val;
/* Check to see if this is an array */
n = array_index_calc(n, &array, &val);
h = hash(n);
c = n[0];
if (!ksh_isalphx(c)) {
if (array)
errorf("bad substitution");
vp = &vtemp;
vp->flag = DEFINED;
vp->type = 0;
vp->areap = ATEMP;
*vp->name = c;
if (ksh_isdigit(c)) {
for (c = 0; ksh_isdigit(*n); n++)
c = c*10 + *n-'0';
if (c <= l->argc)
/* setstr can't fail here */
setstr(vp, l->argv[c], KSH_RETURN_ERROR);
vp->flag |= RDONLY;
return vp;
}
vp->flag |= RDONLY;
if (n[1] != '\0')
return vp;
vp->flag |= ISSET|INTEGER;
switch (c) {
case '$':
vp->val.i = kshpid;
break;
case '!':
/* If no job, expand to nothing */
if ((vp->val.i = j_async()) == 0)
vp->flag &= ~(ISSET|INTEGER);
break;
case '?':
vp->val.i = exstat;
break;
case '#':
vp->val.i = l->argc;
break;
case '-':
vp->flag &= ~INTEGER;
vp->val.s = getoptions();
break;
default:
vp->flag &= ~(ISSET|INTEGER);
}
return vp;
}
for (l = e->loc; ; l = l->next) {
vp = ktsearch(&l->vars, n, h);
if (vp != NULL) {
if (array)
return arraysearch(vp, val);
else
return vp;
}
if (l->next == NULL)
break;
}
vp = ktenter(&l->vars, n, h);
if (array)
vp = arraysearch(vp, val);
vp->flag |= DEFINED;
if (special(n))
vp->flag |= SPECIAL;
return vp;
}
/*
* Search for local variable, if not found create locally.
*/
struct tbl *
local(const char *n, bool copy)
{
struct block *l = e->loc;
struct tbl *vp;
unsigned h;
bool array;
int val;
/* Check to see if this is an array */
n = array_index_calc(n, &array, &val);
h = hash(n);
if (!ksh_isalphx(*n)) {
vp = &vtemp;
vp->flag = DEFINED|RDONLY;
vp->type = 0;
vp->areap = ATEMP;
return vp;
}
vp = ktenter(&l->vars, n, h);
if (copy && !(vp->flag & DEFINED)) {
struct block *ll = l;
struct tbl *vq = NULL;
while ((ll = ll->next) && !(vq = ktsearch(&ll->vars, n, h)))
;
if (vq) {
vp->flag |= vq->flag &
(EXPORT | INTEGER | RDONLY | LJUST | RJUST |
ZEROFIL | LCASEV | UCASEV_AL | INT_U | INT_L);
if (vq->flag & INTEGER)
vp->type = vq->type;
vp->u2.field = vq->u2.field;
}
}
if (array)
vp = arraysearch(vp, val);
vp->flag |= DEFINED;
if (special(n))
vp->flag |= SPECIAL;
return vp;
}
/* get variable string value */
char *
str_val(struct tbl *vp)
{
char *s;
if ((vp->flag&SPECIAL))
getspec(vp);
if (!(vp->flag&ISSET))
s = null; /* special to dollar() */
else if (!(vp->flag&INTEGER)) /* string source */
s = vp->val.s + vp->type;
else { /* integer source */
/* worst case number length is when base=2, so use BITS(long) */
/* minus base # number null */
char strbuf[1 + 2 + 1 + 8 * sizeof(long) + 1];
const char *digits = (vp->flag & UCASEV_AL) ?
"0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ" :
"0123456789abcdefghijklmnopqrstuvwxyz";
unsigned long n;
int base;
s = strbuf + sizeof(strbuf);
if (vp->flag & INT_U)
n = (unsigned long) vp->val.i;
else
n = (vp->val.i < 0) ? -vp->val.i : vp->val.i;
base = (vp->type == 0) ? 10 : vp->type;
*--s = '\0';
do {
*--s = digits[n % base];
n /= base;
} while (n != 0);
if (base != 10) {
*--s = '#';
*--s = digits[base % 10];
if (base >= 10)
*--s = digits[base / 10];
}
if (!(vp->flag & INT_U) && vp->val.i < 0)
*--s = '-';
if (vp->flag & (RJUST|LJUST)) /* case already dealt with */
s = formatstr(vp, s);
else
s = str_save(s, ATEMP);
}
return s;
}
/* get variable integer value, with error checking */
long
intval(struct tbl *vp)
{
long num;
int base;
base = getint(vp, &num, false);
if (base == -1)
/* XXX check calls - is error here ok by POSIX? */
errorf("%s: bad number", str_val(vp));
return num;
}
/* set variable to string value */
int
setstr(struct tbl *vq, const char *s, int error_ok)
{
int no_ro_check = error_ok & 0x4;
error_ok &= ~0x4;
if ((vq->flag & RDONLY) && !no_ro_check) {
warningf(true, "%s: is read only", vq->name);
if (!error_ok)
errorfz();
return 0;
}
if (!(vq->flag&INTEGER)) { /* string dest */
if ((vq->flag&ALLOC)) {
/* debugging */
if (s >= vq->val.s &&
s <= vq->val.s + strlen(vq->val.s))
internal_errorf(
"setstr: %s=%s: assigning to self",
vq->name, s);
afree((void*)vq->val.s, vq->areap);
}
vq->flag &= ~(ISSET|ALLOC);
vq->type = 0;
if (s && (vq->flag & (UCASEV_AL|LCASEV|LJUST|RJUST)))
s = formatstr(vq, s);
if ((vq->flag&EXPORT))
export(vq, s);
else {
vq->val.s = str_save(s, vq->areap);
vq->flag |= ALLOC;
}
} else { /* integer dest */
if (!v_evaluate(vq, s, error_ok, true))
return 0;
}
vq->flag |= ISSET;
if ((vq->flag&SPECIAL))
setspec(vq);
return 1;
}
/* set variable to integer */
void
setint(struct tbl *vq, long int n)
{
if (!(vq->flag&INTEGER)) {
struct tbl *vp = &vtemp;
vp->flag = (ISSET|INTEGER);
vp->type = 0;
vp->areap = ATEMP;
vp->val.i = n;
/* setstr can't fail here */
setstr(vq, str_val(vp), KSH_RETURN_ERROR);
} else
vq->val.i = n;
vq->flag |= ISSET;
if ((vq->flag&SPECIAL))
setspec(vq);
}
int
getint(struct tbl *vp, long int *nump, bool arith)
{
char *s;
int c;
int base, neg;
int have_base = 0;
long num;
if (vp->flag&SPECIAL)
getspec(vp);
/* XXX is it possible for ISSET to be set and val.s to be 0? */
if (!(vp->flag&ISSET) || (!(vp->flag&INTEGER) && vp->val.s == NULL))
return -1;
if (vp->flag&INTEGER) {
*nump = vp->val.i;
return vp->type;
}
s = vp->val.s + vp->type;
if (s == NULL) /* redundant given initial test */
s = null;
base = 10;
num = 0;
neg = 0;
if (arith && *s == '0' && *(s+1)) {
s++;
if (*s == 'x' || *s == 'X') {
s++;
base = 16;
} else if (vp->flag & ZEROFIL) {
while (*s == '0')
s++;
} else
base = 8;
have_base++;
}
for (c = *s++; c ; c = *s++) {
if (c == '-') {
neg++;
continue;
} else if (c == '#') {
base = (int) num;
if (have_base || base < 2 || base > 36)
return -1;
num = 0;
have_base = 1;
continue;
} else if (ksh_isdigit(c))
c -= '0';
else if (ksh_islower(c))
c -= 'a' - 10;
else if (ksh_isupper(c))
c -= 'A' - 10;
else
return -1;
if (c < 0 || c >= base)
return -1;
num = num * base + c;
}
if (neg)
num = -num;
*nump = num;
return base;
}
/* convert variable vq to integer variable, setting its value from vp
* (vq and vp may be the same)
*/
struct tbl *
setint_v(struct tbl *vq, struct tbl *vp, bool arith)
{
int base;
long num;
if ((base = getint(vp, &num, arith)) == -1)
return NULL;
if (!(vq->flag & INTEGER) && (vq->flag & ALLOC)) {
vq->flag &= ~ALLOC;
afree(vq->val.s, vq->areap);
}
vq->val.i = num;
if (vq->type == 0) /* default base */
vq->type = base;
vq->flag |= ISSET|INTEGER;
if (vq->flag&SPECIAL)
setspec(vq);
return vq;
}
static char *
formatstr(struct tbl *vp, const char *s)
{
int olen, nlen;
char *p, *q;
olen = strlen(s);
if (vp->flag & (RJUST|LJUST)) {
if (!vp->u2.field) /* default field width */
vp->u2.field = olen;
nlen = vp->u2.field;
} else
nlen = olen;
p = (char *) alloc(nlen + 1, ATEMP);
if (vp->flag & (RJUST|LJUST)) {
int slen;
if (vp->flag & RJUST) {
const char *qq = s + olen;
/* strip trailing spaces (at&t uses qq[-1] == ' ') */
while (qq > s && ksh_isspace(qq[-1]))
--qq;
slen = qq - s;
if (slen > vp->u2.field) {
s += slen - vp->u2.field;
slen = vp->u2.field;
}
if (vp->u2.field - slen)
memset(p, (vp->flag & ZEROFIL) ? '0' : ' ',
vp->u2.field - slen);
shf_snprintf(p + vp->u2.field - slen,
nlen + 1 - (vp->u2.field - slen),
"%.*s", slen, s);
} else {
/* strip leading spaces/zeros */
while (ksh_isspace(*s))
s++;
if (vp->flag & ZEROFIL)
while (*s == '0')
s++;
shf_snprintf(p, nlen + 1, "%-*.*s",
vp->u2.field, vp->u2.field, s);
}
} else
memcpy(p, s, olen + 1);
if (vp->flag & UCASEV_AL) {
for (q = p; *q; q++)
*q = ksh_toupper(*q);
} else if (vp->flag & LCASEV) {
for (q = p; *q; q++)
*q = ksh_tolower(*q);
}
return p;
}
/*
* make vp->val.s be "name=value" for quick exporting.
*/
static void
export(struct tbl *vp, const char *val)
{
char *xp;
char *op = (vp->flag&ALLOC) ? vp->val.s : NULL;
int namelen = strlen(vp->name);
int vallen = strlen(val) + 1;
vp->flag |= ALLOC;
xp = (char*)alloc(namelen + 1 + vallen, vp->areap);
memcpy(vp->val.s = xp, vp->name, namelen);
xp += namelen;
*xp++ = '=';
vp->type = xp - vp->val.s; /* offset to value */
memcpy(xp, val, vallen);
if (op != NULL)
afree((void*)op, vp->areap);
}
/*
* lookup variable (according to (set&LOCAL)),
* set its attributes (INTEGER, RDONLY, EXPORT, TRACE, LJUST, RJUST, ZEROFIL,
* LCASEV, UCASEV_AL), and optionally set its value if an assignment.
*/
struct tbl *
typeset(const char *var, Tflag set, Tflag clr, int field, int base)
{
struct tbl *vp;
struct tbl *vpbase, *t;
char *tvar;
const char *val;
/* check for valid variable name, search for value */
val = skip_varname(var, false);
if (val == var)
return NULL;
if (*val == '[') {
int len;
len = array_ref_len(val);
if (len == 0)
return NULL;
/* IMPORT is only used when the shell starts up and is
* setting up its environment. Allow only simple array
* references at this time since parameter/command substitution
* is preformed on the [expression] which would be a major
* security hole.
*/
if (set & IMPORT) {
int i;
for (i = 1; i < len - 1; i++)
if (!ksh_isdigit(val[i]))
return NULL;
}
val += len;
}
if (*val == '=')
tvar = str_nsave(var, val++ - var, ATEMP);
else {
/* Importing from original environment: must have an = */
if (set & IMPORT)
return NULL;
tvar = str_save(var, ATEMP);
val = NULL;
}
/* Prevent typeset from creating a local PATH/ENV/SHELL */
if (Flag(FRESTRICTED) && (strcmp(tvar, "PATH") == 0 ||
strcmp(tvar, "ENV") == 0 || strcmp(tvar, "SHELL") == 0))
errorf("%s: restricted", tvar);
vp = (set&LOCAL) ? local(tvar, (set & LOCAL_COPY) ? true : false) :
global(tvar);
set &= ~(LOCAL|LOCAL_COPY);
vpbase = (vp->flag & ARRAY) ? global(arrayname(var)) : vp;
/* only allow export flag to be set. at&t ksh allows any attribute to
* be changed which means it can be truncated or modified (-L/-R/-Z/-i)
*/
if ((vpbase->flag&RDONLY) &&
(val || clr || (set & ~EXPORT)))
/* XXX check calls - is error here ok by POSIX? */
errorf("%s: is read only", tvar);
afree(tvar, ATEMP);
/* most calls are with set/clr == 0 */
if (set | clr) {
int ok = 1;
/* XXX if x[0] isn't set, there will be problems: need to have
* one copy of attributes for arrays...
*/
for (t = vpbase; t; t = t->u.array) {
int fake_assign;
char *s = NULL;
char *free_me = NULL;
fake_assign = (t->flag & ISSET) && (!val || t != vp) &&
((set & (UCASEV_AL|LCASEV|LJUST|RJUST|ZEROFIL)) ||
((t->flag & INTEGER) && (clr & INTEGER)) ||
(!(t->flag & INTEGER) && (set & INTEGER)));
if (fake_assign) {
if (t->flag & INTEGER) {
s = str_val(t);
free_me = NULL;
} else {
s = t->val.s + t->type;
free_me = (t->flag & ALLOC) ? t->val.s :
NULL;
}
t->flag &= ~ALLOC;
}
if (!(t->flag & INTEGER) && (set & INTEGER)) {
t->type = 0;
t->flag &= ~ALLOC;
}
t->flag = (t->flag | set) & ~clr;
/* Don't change base if assignment is to be done,
* in case assignment fails.
*/
if ((set & INTEGER) && base > 0 && (!val || t != vp))
t->type = base;
if (set & (LJUST|RJUST|ZEROFIL))
t->u2.field = field;
if (fake_assign) {
if (!setstr(t, s, KSH_RETURN_ERROR)) {
/* Somewhat arbitrary action here:
* zap contents of variable, but keep
* the flag settings.
*/
ok = 0;
if (t->flag & INTEGER)
t->flag &= ~ISSET;
else {
if (t->flag & ALLOC)
afree((void*) t->val.s,
t->areap);
t->flag &= ~(ISSET|ALLOC);
t->type = 0;
}
}
if (free_me)
afree((void *) free_me, t->areap);
}
}
if (!ok)
errorfz();
}
if (val != NULL) {
if (vp->flag&INTEGER) {
/* do not zero base before assignment */
setstr(vp, val, KSH_UNWIND_ERROR | 0x4);
/* Done after assignment to override default */
if (base > 0)
vp->type = base;
} else
/* setstr can't fail (readonly check already done) */
setstr(vp, val, KSH_RETURN_ERROR | 0x4);
}
/* only x[0] is ever exported, so use vpbase */
if ((vpbase->flag&EXPORT) && !(vpbase->flag&INTEGER) &&
vpbase->type == 0)
export(vpbase, (vpbase->flag&ISSET) ? vpbase->val.s : null);
return vp;
}
/* Unset a variable. array_ref is set if there was an array reference in
* the name lookup (eg, x[2]).
*/
void
unset(struct tbl *vp, int array_ref)
{
if (vp->flag & ALLOC)
afree((void*)vp->val.s, vp->areap);
if ((vp->flag & ARRAY) && !array_ref) {
struct tbl *a, *tmp;
/* Free up entire array */
for (a = vp->u.array; a; ) {
tmp = a;
a = a->u.array;
if (tmp->flag & ALLOC)
afree((void *) tmp->val.s, tmp->areap);
afree(tmp, tmp->areap);
}
vp->u.array = NULL;
}
/* If foo[0] is being unset, the remainder of the array is kept... */
vp->flag &= SPECIAL | (array_ref ? ARRAY|DEFINED : 0);
if (vp->flag & SPECIAL)
unsetspec(vp); /* responsible for 'unspecial'ing var */
}
/* return a pointer to the first char past a legal variable name (returns the
* argument if there is no legal name, returns * a pointer to the terminating
* null if whole string is legal).
*/
const char *
skip_varname(const char *s, int aok)
{
int alen;
if (s && ksh_isalphx(*s)) {
while (*++s && ksh_isalnux(*s))
;
if (aok && *s == '[' && (alen = array_ref_len(s)))
s += alen;
}
return (s);
}
/* Return a pointer to the first character past any legal variable name. */
const char *
skip_wdvarname(const char *s,
int aok) /* skip array de-reference? */
{
if (s[0] == CHAR && ksh_isalphx(s[1])) {
do {
s += 2;
} while (s[0] == CHAR && ksh_isalnux(s[1]));
if (aok && s[0] == CHAR && s[1] == '[') {
/* skip possible array de-reference */
const char *p = s;
char c;
int depth = 0;
while (1) {
if (p[0] != CHAR)
break;
c = p[1];
p += 2;
if (c == '[')
depth++;
else if (c == ']' && --depth == 0) {
s = p;
break;
}
}
}
}
return (s);
}
/* Check if coded string s is a variable name */
int
is_wdvarname(const char *s, int aok)
{
const char *p = skip_wdvarname(s, aok);
return p != s && p[0] == EOS;
}
/* Check if coded string s is a variable assignment */
int
is_wdvarassign(const char *s)
{
const char *p = skip_wdvarname(s, true);
return p != s && p[0] == CHAR && p[1] == '=';
}
/*
* Make the exported environment from the exported names in the dictionary.
*/
char **
makenv(void)
{
struct block *l;
XPtrV env;
struct tbl *vp, **vpp;
int i;
XPinit(env, 64);
for (l = e->loc; l != NULL; l = l->next)
for (vpp = l->vars.tbls, i = l->vars.size; --i >= 0; )
if ((vp = *vpp++) != NULL &&
(vp->flag&(ISSET|EXPORT)) == (ISSET|EXPORT)) {
struct block *l2;
struct tbl *vp2;
unsigned h = hash(vp->name);
/* unexport any redefined instances */
for (l2 = l->next; l2 != NULL; l2 = l2->next) {
vp2 = ktsearch(&l2->vars, vp->name, h);
if (vp2 != NULL)
vp2->flag &= ~EXPORT;
}
if ((vp->flag&INTEGER)) {
/* integer to string */
char *val;
val = str_val(vp);
vp->flag &= ~(INTEGER|RDONLY);
/* setstr can't fail here */
setstr(vp, val, KSH_RETURN_ERROR);
}
XPput(env, vp->val.s);
}
XPput(env, NULL);
return (char **) XPclose(env);
}
/*
* Get us a random number, either from rand(3) or arc4random(3), with
* the latter being preferred. If Flag(FARC4RANDOM) is 0, we use rand(3),
* otherwise arc4random(3). We have static caches to make change_random
* and writes to $RANDOM a cheap operation.
*/
#if HAVE_ARC4RANDOM
static uint64_t rnd_cache = 0;
static char rnd_lastflag = 2;
#endif
static int
rnd_get(void)
{
#if HAVE_ARC4RANDOM
#if HAVE_ARC4RANDOM_PUSHB
uint32_t rv = 0;
#endif
if (Flag(FARC4RANDOM) != rnd_lastflag) {
if (Flag(FARC4RANDOM) == 0) {
/* transition to 0 by set: srand */
srand(arc4random() & 0x7FFF);
} else if (rnd_lastflag == 0) {
/* transition from 0: addrandom */
rnd_cache ^= rand();
}
rnd_lastflag = Flag(FARC4RANDOM);
}
if (Flag(FARC4RANDOM)) {
if (rnd_cache)
#if HAVE_ARC4RANDOM_PUSHB
rv = arc4random_pushb(&rnd_cache, sizeof (rnd_cache));
#else
arc4random_addrandom((void *)&rnd_cache,
sizeof (rnd_cache));
#endif
rnd_cache = 0;
return ((
#if HAVE_ARC4RANDOM_PUSHB
rv ? rv :
#endif
arc4random()) & 0x7FFF);
}
#endif
return (rand() & 0x7FFF);
}
static void
rnd_set(long newval)
{
#if HAVE_ARC4RANDOM
rnd_cache ^= (((uint64_t)newval) << 15) | rand();
if (Flag(FARC4RANDOM) == 1)
return;
if (Flag(FARC4RANDOM) == 2)
Flag(FARC4RANDOM) = 0;
/* transition to 0 by write: only srand */
rnd_lastflag = 0;
#endif
srand(newval & 0x7FFF);
}
/*
* Called after a fork in parent to bump the random number generator.
* Done to ensure children will not get the same random number sequence
* if the parent doesn't use $RANDOM.
*/
void
change_random(uint64_t newval)
{
int rval = 0;
newval &= 0x00001FFFFFFFFFFF;
newval |= (uint64_t)rand() << 45;
#if HAVE_ARC4RANDOM
if (Flag(FARC4RANDOM)) {
rnd_cache ^= newval;
return;
}
#endif
rval += newval & 0x7FFF;
newval >>= 15;
rval += newval & 0x7FFF;
newval >>= 15;
rval += newval & 0x7FFF;
newval >>= 15;
rval += newval;
rval = (rval & 0x7FFF) ^ (rval >> 15);
srand(rval);
}
/*
* handle special variables with side effects - PATH, SECONDS.
*/
/* Test if name is a special parameter */
static int
special(const char *name)
{
struct tbl *tp;
tp = ktsearch(&specials, name, hash(name));
return tp && (tp->flag & ISSET) ? tp->type : V_NONE;
}
/* Make a variable non-special */
static void
unspecial(const char *name)
{
struct tbl *tp;
tp = ktsearch(&specials, name, hash(name));
if (tp)
ktdelete(tp);
}
static time_t seconds; /* time SECONDS last set */
static int user_lineno; /* what user set $LINENO to */
static void
getspec(struct tbl *vp)
{
switch (special(vp->name)) {
case V_SECONDS:
vp->flag &= ~SPECIAL;
/* On start up the value of SECONDS is used before seconds
* has been set - don't do anything in this case
* (see initcoms[] in main.c).
*/
if (vp->flag & ISSET) {
struct timeval tv;
gettimeofday(&tv, NULL);
setint(vp, tv.tv_sec - seconds);
}
vp->flag |= SPECIAL;
break;
case V_RANDOM:
vp->flag &= ~SPECIAL;
setint(vp, rnd_get());
vp->flag |= SPECIAL;
break;
case V_HISTSIZE:
vp->flag &= ~SPECIAL;
setint(vp, (long) histsize);
vp->flag |= SPECIAL;
break;
case V_OPTIND:
vp->flag &= ~SPECIAL;
setint(vp, (long) user_opt.uoptind);
vp->flag |= SPECIAL;
break;
case V_LINENO:
vp->flag &= ~SPECIAL;
setint(vp, (long) current_lineno + user_lineno);
vp->flag |= SPECIAL;
break;
}
}
static void
setspec(struct tbl *vp)
{
char *s;
switch (special(vp->name)) {
case V_PATH:
if (path)
afree(path, APERM);
s = str_val(vp);
path = str_save(s, APERM);
flushcom(1); /* clear tracked aliases */
break;
case V_IFS:
setctypes(s = str_val(vp), C_IFS);
ifs0 = *s;
break;
case V_OPTIND:
vp->flag &= ~SPECIAL;
getopts_reset((int)intval(vp));
vp->flag |= SPECIAL;
break;
case V_TMPDIR:
if (tmpdir) {
afree(tmpdir, APERM);
tmpdir = NULL;
}
/* Use tmpdir iff it is an absolute path, is writable and
* searchable and is a directory...
*/
{
struct stat statb;
s = str_val(vp);
if (s[0] == '/' && access(s, W_OK|X_OK) == 0 &&
stat(s, &statb) == 0 && S_ISDIR(statb.st_mode))
tmpdir = str_save(s, APERM);
}
break;
case V_HISTSIZE:
vp->flag &= ~SPECIAL;
sethistsize((int)intval(vp));
vp->flag |= SPECIAL;
break;
#if HAVE_PERSISTENT_HISTORY
case V_HISTFILE:
sethistfile(str_val(vp));
break;
#endif
case V_COLUMNS:
if ((x_cols = intval(vp)) <= MIN_COLS)
x_cols = MIN_COLS;
break;
case V_RANDOM:
vp->flag &= ~SPECIAL;
rnd_set(intval(vp));
vp->flag |= SPECIAL;
break;
case V_SECONDS:
vp->flag &= ~SPECIAL;
{
struct timeval tv;
gettimeofday(&tv, NULL);
seconds = tv.tv_sec - intval(vp);
}
vp->flag |= SPECIAL;
break;
case V_TMOUT:
/* at&t ksh seems to do this (only listen if integer) */
if (vp->flag & INTEGER)
ksh_tmout = vp->val.i >= 0 ? vp->val.i : 0;
break;
case V_LINENO:
vp->flag &= ~SPECIAL;
/* The -1 is because line numbering starts at 1. */
user_lineno = (unsigned int)intval(vp) - current_lineno - 1;
vp->flag |= SPECIAL;
break;
}
}
static void
unsetspec(struct tbl *vp)
{
switch (special(vp->name)) {
case V_PATH:
if (path)
afree(path, APERM);
path = str_save(def_path, APERM);
flushcom(1); /* clear tracked aliases */
break;
case V_IFS:
setctypes(" \t\n", C_IFS);
ifs0 = ' ';
break;
case V_TMPDIR:
/* should not become unspecial */
if (tmpdir) {
afree(tmpdir, APERM);
tmpdir = NULL;
}
break;
case V_LINENO:
case V_RANDOM:
case V_SECONDS:
case V_TMOUT: /* at&t ksh leaves previous value in place */
unspecial(vp->name);
break;
/* at&t ksh man page says OPTIND, OPTARG and _ lose special meaning,
* but OPTARG does not (still set by getopts) and _ is also still
* set in various places.
* Don't know what at&t does for:
* HISTSIZE, HISTFILE,
* Unsetting these in at&t ksh does not loose the 'specialness':
* no effect: IFS, COLUMNS, PATH, TMPDIR
*/
}
}
/*
* Search for (and possibly create) a table entry starting with
* vp, indexed by val.
*/
static struct tbl *
arraysearch(struct tbl *vp, int val)
{
struct tbl *prev, *curr, *new;
size_t namelen = strlen(vp->name) + 1;
vp->flag |= ARRAY|DEFINED;
vp->index = 0;
/* The table entry is always [0] */
if (val == 0)
return vp;
prev = vp;
curr = vp->u.array;
while (curr && curr->index < val) {
prev = curr;
curr = curr->u.array;
}
if (curr && curr->index == val) {
if (curr->flag&ISSET)
return curr;
else
new = curr;
} else
new = (struct tbl *)alloc(sizeof(struct tbl) + namelen,
vp->areap);
strlcpy(new->name, vp->name, namelen);
new->flag = vp->flag & ~(ALLOC|DEFINED|ISSET|SPECIAL);
new->type = vp->type;
new->areap = vp->areap;
new->u2.field = vp->u2.field;
new->index = val;
if (curr != new) { /* not reusing old array entry */
prev->u.array = new;
new->u.array = curr;
}
return new;
}
/* Return the length of an array reference (eg, [1+2]) - cp is assumed
* to point to the open bracket. Returns 0 if there is no matching closing
* bracket.
*/
int
array_ref_len(const char *cp)
{
const char *s = cp;
int c;
int depth = 0;
while ((c = *s++) && (c != ']' || --depth))
if (c == '[')
depth++;
if (!c)
return 0;
return s - cp;
}
/*
* Make a copy of the base of an array name
*/
char *
arrayname(const char *str)
{
const char *p;
if ((p = cstrchr(str, '[')) == 0)
/* Shouldn't happen, but why worry? */
return str_save(str, ATEMP);
return str_nsave(str, p - str, ATEMP);
}
/* Set (or overwrite, if !reset) the array variable var to the values in vals.
*/
void
set_array(const char *var, int reset, const char **vals)
{
struct tbl *vp, *vq;
int i;
/* to get local array, use "typeset foo; set -A foo" */
vp = global(var);
/* Note: at&t ksh allows set -A but not set +A of a read-only var */
if ((vp->flag&RDONLY))
errorf("%s: is read only", var);
/* This code is quite non-optimal */
if (reset > 0)
/* trash existing values and attributes */
unset(vp, 0);
/* todo: would be nice for assignment to completely succeed or
* completely fail. Only really effects integer arrays:
* evaluation of some of vals[] may fail...
*/
for (i = 0; vals[i]; i++) {
vq = arraysearch(vp, i);
/* would be nice to deal with errors here... (see above) */
setstr(vq, vals[i], KSH_RETURN_ERROR);
}
}
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