/*
* Perform tilde expansion, placing the result in the stack string and
* returning the next position in the input string to process.
*/
static const char *
exptilde(const char *p, int flag)
{
char c;
const char *startp = p;
const char *user;
struct passwd *pw;
char *home;
int len;
for (;;) {
c = *p;
switch(c) {
case CTLESC: /* This means CTL* are always considered quoted. */
case CTLVAR:
case CTLBACKQ:
case CTLBACKQ | CTLQUOTE:
case CTLARI:
case CTLENDARI:
case CTLQUOTEMARK:
return (startp);
case ':':
if ((flag & EXP_VARTILDE) == 0)
break;
/* FALLTHROUGH */
case '\0':
case '/':
case CTLENDVAR:
len = p - startp - 1;
STPUTBIN(startp + 1, len, expdest);
STACKSTRNUL(expdest);
user = expdest - len;
if (*user == '\0') {
home = lookupvar("HOME");
} else {
pw = getpwnam(user);
home = pw != NULL ? pw->pw_dir : NULL;
}
STADJUST(-len, expdest);
if (home == NULL || *home == '\0')
return (startp);
strtodest(home, flag, VSNORMAL, 1, NULL);
return (p);
}
p++;
}
}
static char *
evalvar(char *p, int flag)
{
int subtype;
int varflags;
char *var;
const char *val;
int patloc;
int c;
int set;
int special;
int startloc;
int varlen;
int varlenb;
int easy;
int quotes = flag & (EXP_FULL | EXP_CASE);
int record = 0;
varflags = (unsigned char)*p++;
subtype = varflags & VSTYPE;
var = p;
special = 0;
if (! is_name(*p))
special = 1;
p = strchr(p, '=') + 1;
again: /* jump here after setting a variable with ${var=text} */
if (varflags & VSLINENO) {
set = 1;
special = 1;
val = NULL;
} else if (special) {
set = varisset(var, varflags & VSNUL);
val = NULL;
} else {
val = bltinlookup(var, 1);
if (val == NULL || ((varflags & VSNUL) && val[0] == '\0')) {
val = NULL;
set = 0;
} else
set = 1;
}
varlen = 0;
startloc = expdest - stackblock();
if (!set && uflag && *var != '@' && *var != '*') {
switch (subtype) {
case VSNORMAL:
case VSTRIMLEFT:
case VSTRIMLEFTMAX:
case VSTRIMRIGHT:
case VSTRIMRIGHTMAX:
case VSLENGTH:
error("%.*s: parameter not set", (int)(p - var - 1),
var);
}
}
if (set && subtype != VSPLUS) {
/* insert the value of the variable */
if (special) {
if (varflags & VSLINENO)
STPUTBIN(var, p - var - 1, expdest);
else
varvalue(var, varflags & VSQUOTE, subtype, flag);
if (subtype == VSLENGTH) {
varlenb = expdest - stackblock() - startloc;
varlen = varlenb;
if (localeisutf8) {
val = stackblock() + startloc;
for (;val != expdest; val++)
if ((*val & 0xC0) == 0x80)
varlen--;
}
STADJUST(-varlenb, expdest);
}
} else {
if (subtype == VSLENGTH) {
for (;*val; val++)
if (!localeisutf8 ||
(*val & 0xC0) != 0x80)
varlen++;
}
else
strtodest(val, flag, subtype,
varflags & VSQUOTE);
}
}
if (subtype == VSPLUS)
set = ! set;
easy = ((varflags & VSQUOTE) == 0 ||
(*var == '@' && shellparam.nparam != 1));
switch (subtype) {
case VSLENGTH:
expdest = cvtnum(varlen, expdest);
record = 1;
break;
case VSNORMAL:
record = easy;
break;
case VSPLUS:
case VSMINUS:
if (!set) {
argstr(p, flag | (flag & EXP_FULL ? EXP_SPLIT_LIT : 0) |
(varflags & VSQUOTE ? EXP_LIT_QUOTED : 0));
break;
}
record = easy;
break;
case VSTRIMLEFT:
case VSTRIMLEFTMAX:
case VSTRIMRIGHT:
case VSTRIMRIGHTMAX:
if (!set)
break;
/*
* Terminate the string and start recording the pattern
* right after it
*/
STPUTC('\0', expdest);
patloc = expdest - stackblock();
if (subevalvar(p, NULL, patloc, subtype,
startloc, varflags, quotes) == 0) {
int amount = (expdest - stackblock() - patloc) + 1;
STADJUST(-amount, expdest);
}
/* Remove any recorded regions beyond start of variable */
removerecordregions(startloc);
record = 1;
break;
case VSASSIGN:
case VSQUESTION:
if (!set) {
if (subevalvar(p, var, 0, subtype, startloc, varflags,
quotes)) {
varflags &= ~VSNUL;
/*
* Remove any recorded regions beyond
* start of variable
*/
removerecordregions(startloc);
goto again;
}
break;
}
record = easy;
break;
case VSERROR:
c = p - var - 1;
error("${%.*s%s}: Bad substitution", c, var,
(c > 0 && *p != CTLENDVAR) ? "..." : "");
default:
abort();
}
if (record)
recordregion(startloc, expdest - stackblock(),
varflags & VSQUOTE || (ifsset() && ifsval()[0] == '\0' &&
(*var == '@' || *var == '*')));
if (subtype != VSNORMAL) { /* skip to end of alternative */
int nesting = 1;
for (;;) {
if ((c = *p++) == CTLESC)
p++;
else if (c == CTLBACKQ || c == (CTLBACKQ|CTLQUOTE)) {
if (set)
argbackq = argbackq->next;
} else if (c == CTLVAR) {
if ((*p++ & VSTYPE) != VSNORMAL)
nesting++;
} else if (c == CTLENDVAR) {
if (--nesting == 0)
break;
}
}
}
return p;
}
