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mksh/eval.c

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/* $OpenBSD: eval.c,v 1.40 2013/09/14 20:09:30 millert Exp $ */
/*-
* Copyright (c) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010,
* 2011, 2012, 2013, 2014, 2015, 2016
* mirabilos <m@mirbsd.org>
*
* Provided that these terms and disclaimer and all copyright notices
* are retained or reproduced in an accompanying document, permission
* is granted to deal in this work without restriction, including un-
* limited rights to use, publicly perform, distribute, sell, modify,
* merge, give away, or sublicence.
*
* This work is provided "AS IS" and WITHOUT WARRANTY of any kind, to
* the utmost extent permitted by applicable law, neither express nor
* implied; without malicious intent or gross negligence. In no event
* may a licensor, author or contributor be held liable for indirect,
* direct, other damage, loss, or other issues arising in any way out
* of dealing in the work, even if advised of the possibility of such
* damage or existence of a defect, except proven that it results out
* of said person's immediate fault when using the work as intended.
*/
#include "sh.h"
__RCSID("$MirOS: src/bin/mksh/eval.c,v 1.179 2016/01/14 22:30:43 tg Exp $");
/*
* string expansion
*
* first pass: quoting, IFS separation, ~, ${}, $() and $(()) substitution.
* second pass: alternation ({,}), filename expansion (*?[]).
*/
/* expansion generator state */
typedef struct {
/* not including an "int type;" member, see expand() */
/* string */
const char *str;
/* source */
union {
/* string[] */
const char **strv;
/* file */
struct shf *shf;
} u;
/* variable in ${var...} */
struct tbl *var;
/* split "$@" / call waitlast in $() */
bool split;
} Expand;
#define XBASE 0 /* scanning original */
#define XSUB 1 /* expanding ${} string */
#define XARGSEP 2 /* ifs0 between "$*" */
#define XARG 3 /* expanding $*, $@ */
#define XCOM 4 /* expanding $() */
#define XNULLSUB 5 /* "$@" when $# is 0 (don't generate word) */
#define XSUBMID 6 /* middle of expanding ${} */
/* States used for field splitting */
#define IFS_WORD 0 /* word has chars (or quotes except "$@") */
#define IFS_WS 1 /* have seen IFS white-space */
#define IFS_NWS 2 /* have seen IFS non-white-space */
#define IFS_IWS 3 /* begin of word, ignore IFS WS */
#define IFS_QUOTE 4 /* beg.w/quote, become IFS_WORD unless "$@" */
static int varsub(Expand *, const char *, const char *, int *, int *);
static int comsub(Expand *, const char *, int);
static char *valsub(struct op *, Area *);
static char *trimsub(char *, char *, int);
static void glob(char *, XPtrV *, bool);
static void globit(XString *, char **, char *, XPtrV *, int);
static const char *maybe_expand_tilde(const char *, XString *, char **, bool);
#ifndef MKSH_NOPWNAM
static char *homedir(char *);
#endif
static void alt_expand(XPtrV *, char *, char *, char *, int);
static int utflen(const char *) MKSH_A_PURE;
static void utfincptr(const char *, mksh_ari_t *);
/* UTFMODE functions */
static int
utflen(const char *s)
{
size_t n;
if (UTFMODE) {
n = 0;
while (*s) {
s += utf_ptradj(s);
++n;
}
} else
n = strlen(s);
if (n > 2147483647)
n = 2147483647;
return ((int)n);
}
static void
utfincptr(const char *s, mksh_ari_t *lp)
{
const char *cp = s;
while ((*lp)--)
cp += utf_ptradj(cp);
*lp = cp - s;
}
/* compile and expand word */
char *
substitute(const char *cp, int f)
{
struct source *s, *sold;
sold = source;
s = pushs(SWSTR, ATEMP);
s->start = s->str = cp;
source = s;
if (yylex(ONEWORD) != LWORD)
internal_errorf("bad substitution");
source = sold;
afree(s, ATEMP);
return (evalstr(yylval.cp, f));
}
/*
* expand arg-list
*/
char **
eval(const char **ap, int f)
{
XPtrV w;
if (*ap == NULL) {
union mksh_ccphack vap;
vap.ro = ap;
return (vap.rw);
}
XPinit(w, 32);
/* space for shell name */
XPput(w, NULL);
while (*ap != NULL)
expand(*ap++, &w, f);
XPput(w, NULL);
return ((char **)XPclose(w) + 1);
}
/*
* expand string
*/
char *
evalstr(const char *cp, int f)
{
XPtrV w;
char *dp = null;
XPinit(w, 1);
expand(cp, &w, f);
if (XPsize(w))
dp = *XPptrv(w);
XPfree(w);
return (dp);
}
/*
* expand string - return only one component
* used from iosetup to expand redirection files
*/
char *
evalonestr(const char *cp, int f)
{
XPtrV w;
char *rv;
XPinit(w, 1);
expand(cp, &w, f);
switch (XPsize(w)) {
case 0:
rv = null;
break;
case 1:
rv = (char *) *XPptrv(w);
break;
default:
rv = evalstr(cp, f&~DOGLOB);
break;
}
XPfree(w);
return (rv);
}
/* for nested substitution: ${var:=$var2} */
typedef struct SubType {
struct tbl *var; /* variable for ${var..} */
struct SubType *prev; /* old type */
struct SubType *next; /* poped type (to avoid re-allocating) */
size_t base; /* begin position of expanded word */
short stype; /* [=+-?%#] action after expanded word */
short f; /* saved value of f (DOPAT, etc) */
uint8_t quotep; /* saved value of quote (for ${..[%#]..}) */
uint8_t quotew; /* saved value of quote (for ${..[+-=]..}) */
} SubType;
void
expand(
/* input word */
const char *ccp,
/* output words */
XPtrV *wp,
/* DO* flags */
int f)
{
int c = 0;
/* expansion type */
int type;
/* quoted */
int quote = 0;
/* destination string and live pointer */
XString ds;
char *dp;
/* source */
const char *sp;
/* second pass flags */
int fdo;
/* have word */
int word;
/* field splitting of parameter/command substitution */
int doblank;
/* expansion variables */
Expand x = {
NULL, { NULL }, NULL, 0
};
SubType st_head, *st;
/* record number of trailing newlines in COMSUB */
int newlines = 0;
bool saw_eq, make_magic;
unsigned int tilde_ok;
size_t len;
char *cp;
if (ccp == NULL)
internal_errorf("expand(NULL)");
/* for alias, readonly, set, typeset commands */
if ((f & DOVACHECK) && is_wdvarassign(ccp)) {
f &= ~(DOVACHECK | DOBLANK | DOGLOB | DOTILDE);
f |= DOASNTILDE | DOSCALAR;
}
if (Flag(FNOGLOB))
f &= ~DOGLOB;
if (Flag(FMARKDIRS))
f |= DOMARKDIRS;
if (Flag(FBRACEEXPAND) && (f & DOGLOB))
f |= DOBRACE;
/* init destination string */
Xinit(ds, dp, 128, ATEMP);
type = XBASE;
sp = ccp;
fdo = 0;
saw_eq = false;
/* must be 1/0 */
tilde_ok = (f & (DOTILDE | DOASNTILDE)) ? 1 : 0;
doblank = 0;
make_magic = false;
word = (f&DOBLANK) ? IFS_WS : IFS_WORD;
/* clang doesn't know OSUBST comes before CSUBST */
memset(&st_head, 0, sizeof(st_head));
st = &st_head;
while (/* CONSTCOND */ 1) {
Xcheck(ds, dp);
switch (type) {
case XBASE:
/* original prefixed string */
c = *sp++;
switch (c) {
case EOS:
c = 0;
break;
case CHAR:
c = *sp++;
break;
case QCHAR:
/* temporary quote */
quote |= 2;
c = *sp++;
break;
case OQUOTE:
if (word != IFS_WORD)
word = IFS_QUOTE;
tilde_ok = 0;
quote = 1;
continue;
case CQUOTE:
if (word == IFS_QUOTE)
word = IFS_WORD;
quote = st->quotew;
continue;
case COMSUB:
case FUNSUB:
case VALSUB:
tilde_ok = 0;
if (f & DONTRUNCOMMAND) {
word = IFS_WORD;
*dp++ = '$';
*dp++ = c == COMSUB ? '(' : '{';
if (c != COMSUB)
*dp++ = c == FUNSUB ? ' ' : '|';
while (*sp != '\0') {
Xcheck(ds, dp);
*dp++ = *sp++;
}
if (c != COMSUB) {
*dp++ = ';';
*dp++ = '}';
} else
*dp++ = ')';
} else {
type = comsub(&x, sp, c);
if (type != XBASE && (f & DOBLANK))
doblank++;
sp = strnul(sp) + 1;
newlines = 0;
}
continue;
case EXPRSUB:
tilde_ok = 0;
if (f & DONTRUNCOMMAND) {
word = IFS_WORD;
*dp++ = '$'; *dp++ = '('; *dp++ = '(';
while (*sp != '\0') {
Xcheck(ds, dp);
*dp++ = *sp++;
}
*dp++ = ')'; *dp++ = ')';
} else {
struct tbl v;
v.flag = DEFINED|ISSET|INTEGER;
/* not default */
v.type = 10;
v.name[0] = '\0';
v_evaluate(&v, substitute(sp, 0),
KSH_UNWIND_ERROR, true);
sp = strnul(sp) + 1;
x.str = str_val(&v);
type = XSUB;
if (f & DOBLANK)
doblank++;
}
continue;
case OSUBST: {
/* ${{#}var{:}[=+-?#%]word} */
/*-
* format is:
* OSUBST [{x] plain-variable-part \0
* compiled-word-part CSUBST [}x]
* This is where all syntax checking gets done...
*/
/* skip the { or x (}) */
const char *varname = ++sp;
int stype;
int slen = 0;
/* skip variable */
sp = cstrchr(sp, '\0') + 1;
type = varsub(&x, varname, sp, &stype, &slen);
if (type < 0) {
char *beg, *end, *str;
unwind_substsyn:
/* restore sp */
sp = varname - 2;
end = (beg = wdcopy(sp, ATEMP)) +
(wdscan(sp, CSUBST) - sp);
/* ({) the } or x is already skipped */
if (end < wdscan(beg, EOS))
*end = EOS;
str = snptreef(NULL, 64, "%S", beg);
afree(beg, ATEMP);
errorf("%s: %s", str, "bad substitution");
}
if (f & DOBLANK)
doblank++;
tilde_ok = 0;
if (word == IFS_QUOTE && type != XNULLSUB)
word = IFS_WORD;
if (type == XBASE) {
/* expand? */
if (!st->next) {
SubType *newst;
newst = alloc(sizeof(SubType), ATEMP);
newst->next = NULL;
newst->prev = st;
st->next = newst;
}
st = st->next;
st->stype = stype;
st->base = Xsavepos(ds, dp);
st->f = f;
if (x.var == &vtemp) {
st->var = tempvar();
st->var->flag &= ~INTEGER;
/* can't fail here */
setstr(st->var,
str_val(x.var),
KSH_RETURN_ERROR | 0x4);
} else
st->var = x.var;
st->quotew = st->quotep = quote;
/* skip qualifier(s) */
if (stype)
sp += slen;
switch (stype & 0x17F) {
case 0x100 | '#':
x.str = shf_smprintf("%08X",
(unsigned int)hash(str_val(st->var)));
break;
case 0x100 | 'Q': {
struct shf shf;
shf_sopen(NULL, 0, SHF_WR|SHF_DYNAMIC, &shf);
print_value_quoted(&shf, str_val(st->var));
x.str = shf_sclose(&shf);
break;
}
case '0': {
char *beg, *mid, *end, *stg;
mksh_ari_t from = 0, num = -1, flen, finc = 0;
beg = wdcopy(sp, ATEMP);
mid = beg + (wdscan(sp, ADELIM) - sp);
stg = beg + (wdscan(sp, CSUBST) - sp);
mid[-2] = EOS;
if (mid[-1] == /*{*/'}') {
sp += mid - beg - 1;
end = NULL;
} else {
end = mid +
(wdscan(mid, ADELIM) - mid);
if (end[-1] != /*{*/ '}')
/* more than max delimiters */
goto unwind_substsyn;
end[-2] = EOS;
sp += end - beg - 1;
}
evaluate(substitute(stg = wdstrip(beg, 0), 0),
&from, KSH_UNWIND_ERROR, true);
afree(stg, ATEMP);
if (end) {
evaluate(substitute(stg = wdstrip(mid, 0), 0),
&num, KSH_UNWIND_ERROR, true);
afree(stg, ATEMP);
}
afree(beg, ATEMP);
beg = str_val(st->var);
flen = utflen(beg);
if (from < 0) {
if (-from < flen)
finc = flen + from;
} else
finc = from < flen ? from : flen;
if (UTFMODE)
utfincptr(beg, &finc);
beg += finc;
flen = utflen(beg);
if (num < 0 || num > flen)
num = flen;
if (UTFMODE)
utfincptr(beg, &num);
strndupx(x.str, beg, num, ATEMP);
goto do_CSUBST;
}
case '/': {
char *s, *p, *d, *sbeg, *end;
char *pat, *rrep;
char fpat = 0, *tpat1, *tpat2;
s = wdcopy(sp, ATEMP);
p = s + (wdscan(sp, ADELIM) - sp);
d = s + (wdscan(sp, CSUBST) - sp);
p[-2] = EOS;
if (p[-1] == /*{*/'}')
d = NULL;
else
d[-2] = EOS;
sp += (d ? d : p) - s - 1;
if (!(stype & 0x80) &&
s[0] == CHAR &&
(s[1] == '#' || s[1] == '%'))
fpat = s[1];
pat = evalstr(s + (fpat ? 2 : 0),
DOTILDE | DOSCALAR | DOPAT);
rrep = d ? evalstr(p,
DOTILDE | DOSCALAR) : null;
afree(s, ATEMP);
/* check for special cases */
if (!*pat && !fpat) {
/*
* empty unanchored
* pattern => reject
*/
goto no_repl;
}
if ((stype & 0x80) &&
gmatchx(null, pat, false)) {
/*
* pattern matches empty
* string => don't loop
*/
stype &= ~0x80;
}
/* prepare string on which to work */
strdupx(s, str_val(st->var), ATEMP);
sbeg = s;
/* first see if we have any match at all */
if (fpat == '#') {
/* anchor at the beginning */
tpat1 = shf_smprintf("%s%c*", pat, MAGIC);
tpat2 = tpat1;
} else if (fpat == '%') {
/* anchor at the end */
tpat1 = shf_smprintf("%c*%s", MAGIC, pat);
tpat2 = pat;
} else {
/* float */
tpat1 = shf_smprintf("%c*%s%c*", MAGIC, pat, MAGIC);
tpat2 = tpat1 + 2;
}
again_repl:
/*
* this would not be necessary if gmatchx would return
* the start and end values of a match found, like re*
*/
if (!gmatchx(sbeg, tpat1, false))
goto end_repl;
end = strnul(s);
/* now anchor the beginning of the match */
if (fpat != '#')
while (sbeg <= end) {
if (gmatchx(sbeg, tpat2, false))
break;
else
sbeg++;
}
/* now anchor the end of the match */
p = end;
if (fpat != '%')
while (p >= sbeg) {
bool gotmatch;
c = *p;
*p = '\0';
gotmatch = tobool(gmatchx(sbeg, pat, false));
*p = c;
if (gotmatch)
break;
p--;
}
strndupx(end, s, sbeg - s, ATEMP);
d = shf_smprintf("%s%s%s", end, rrep, p);
afree(end, ATEMP);
sbeg = d + (sbeg - s) + strlen(rrep);
afree(s, ATEMP);
s = d;
if (stype & 0x80)
goto again_repl;
end_repl:
afree(tpat1, ATEMP);
x.str = s;
no_repl:
afree(pat, ATEMP);
if (rrep != null)
afree(rrep, ATEMP);
goto do_CSUBST;
}
case '#':
case '%':
/* ! DOBLANK,DOBRACE */
f = (f & DONTRUNCOMMAND) |
DOPAT | DOTILDE |
DOTEMP | DOSCALAR;
tilde_ok = 1;
st->quotew = quote = 0;
/*
* Prepend open pattern (so |
* in a trim will work as
* expected)
*/
if (!Flag(FSH)) {
*dp++ = MAGIC;
*dp++ = 0x80 | '@';
}
break;
case '=':
/*
* Enabling tilde expansion
* after :s here is
* non-standard ksh, but is
* consistent with rules for
* other assignments. Not
* sure what POSIX thinks of
* this.
* Not doing tilde expansion
* for integer variables is a
* non-POSIX thing - makes
* sense though, since ~ is
* a arithmetic operator.
*/
if (!(x.var->flag & INTEGER))
f |= DOASNTILDE | DOTILDE;
f |= DOTEMP;
/*
* These will be done after the
* value has been assigned.
*/
f &= ~(DOBLANK|DOGLOB|DOBRACE);
tilde_ok = 1;
break;
case '?':
if (*sp == CSUBST)
errorf("%s: parameter null or not set",
st->var->name);
f &= ~DOBLANK;
f |= DOTEMP;
/* FALLTHROUGH */
default:
/* '-' '+' '?' */
if (quote)
word = IFS_WORD;
else if (dp == Xstring(ds, dp))
word = IFS_IWS;
/* Enable tilde expansion */
tilde_ok = 1;
f |= DOTILDE;
}
} else
/* skip word */
sp += wdscan(sp, CSUBST) - sp;
continue;
}
case CSUBST:
/* only get here if expanding word */
do_CSUBST:
/* ({) skip the } or x */
sp++;
/* in case of ${unset:-} */
tilde_ok = 0;
*dp = '\0';
quote = st->quotep;
f = st->f;
if (f & DOBLANK)
doblank--;
switch (st->stype & 0x17F) {
case '#':
case '%':
if (!Flag(FSH)) {
/* Append end-pattern */
*dp++ = MAGIC;
*dp++ = ')';
}
*dp = '\0';
dp = Xrestpos(ds, dp, st->base);
/*
* Must use st->var since calling
* global would break things
* like x[i+=1].
*/
x.str = trimsub(str_val(st->var),
dp, st->stype);
if (x.str[0] != '\0') {
word = IFS_IWS;
type = XSUB;
} else if (quote) {
word = IFS_WORD;
type = XSUB;
} else {
if (dp == Xstring(ds, dp))
word = IFS_IWS;
type = XNULLSUB;
}
if (f & DOBLANK)
doblank++;
st = st->prev;
continue;
case '=':
/*
* Restore our position and substitute
* the value of st->var (may not be
* the assigned value in the presence
* of integer/right-adj/etc attributes).
*/
dp = Xrestpos(ds, dp, st->base);
/*
* Must use st->var since calling
* global would cause with things
* like x[i+=1] to be evaluated twice.
*/
/*
* Note: not exported by FEXPORT
* in AT&T ksh.
*/
/*
* XXX POSIX says readonly is only
* fatal for special builtins (setstr
* does readonly check).
*/
len = strlen(dp) + 1;
setstr(st->var,
debunk(alloc(len, ATEMP),
dp, len), KSH_UNWIND_ERROR);
x.str = str_val(st->var);
type = XSUB;
if (f & DOBLANK)
doblank++;
st = st->prev;
word = quote || (!*x.str && (f & DOSCALAR)) ? IFS_WORD : IFS_IWS;
continue;
case '?':
dp = Xrestpos(ds, dp, st->base);
errorf("%s: %s", st->var->name,
debunk(dp, dp, strlen(dp) + 1));
break;
case '0':
case '/':
case 0x100 | '#':
case 0x100 | 'Q':
dp = Xrestpos(ds, dp, st->base);
type = XSUB;
word = quote || (!*x.str && (f & DOSCALAR)) ? IFS_WORD : IFS_IWS;
if (f & DOBLANK)
doblank++;
st = st->prev;
continue;
/* default: '-' '+' */
}
st = st->prev;
type = XBASE;
continue;
case OPAT:
/* open pattern: *(foo|bar) */
/* Next char is the type of pattern */
make_magic = true;
c = *sp++ | 0x80;
break;
case SPAT:
/* pattern separator (|) */
make_magic = true;
c = '|';
break;
case CPAT:
/* close pattern */
make_magic = true;
c = /*(*/ ')';
break;
}
break;
case XNULLSUB:
/*
* Special case for "$@" (and "${foo[@]}") - no
* word is generated if $# is 0 (unless there is
* other stuff inside the quotes).
*/
type = XBASE;
if (f & DOBLANK) {
doblank--;
if (dp == Xstring(ds, dp) && word != IFS_WORD)
word = IFS_IWS;
}
continue;
case XSUB:
case XSUBMID:
if ((c = *x.str++) == 0) {
type = XBASE;
if (f & DOBLANK)
doblank--;
continue;
}
break;
case XARGSEP:
type = XARG;
quote = 1;
/* FALLTHROUGH */
case XARG:
if ((c = *x.str++) == '\0') {
/*
* force null words to be created so
* set -- "" 2 ""; echo "$@" will do
* the right thing
*/
if (quote && x.split)
word = IFS_WORD;
if ((x.str = *x.u.strv++) == NULL) {
type = XBASE;
if (f & DOBLANK)
doblank--;
continue;
}
c = ifs0;
if ((f & DOHEREDOC)) {
/* pseudo-field-split reliably */
if (c == 0)
c = ' ';
break;
}
if ((f & DOSCALAR)) {
/* do not field-split */
if (x.split) {
c = ' ';
break;
}
if (c == 0)
continue;
}
if (c == 0) {
if (quote && !x.split)
continue;
if (!quote && word == IFS_WS)
continue;
/* this is so we don't terminate */
c = ' ';
/* now force-emit a word */
goto emit_word;
}
if (quote && x.split) {
/* terminate word for "$@" */
type = XARGSEP;
quote = 0;
}
}
break;
case XCOM:
if (x.u.shf == NULL) {
/* $(<...) failed */
subst_exstat = 1;
/* fake EOF */
c = -1;
} else if (newlines) {
/* spit out saved NLs */
c = '\n';
--newlines;
} else {
while ((c = shf_getc(x.u.shf)) == 0 || c == '\n')
if (c == '\n')
/* save newlines */
newlines++;
if (newlines && c != -1) {
shf_ungetc(c, x.u.shf);
c = '\n';
--newlines;
}
}
if (c == -1) {
newlines = 0;
if (x.u.shf)
shf_close(x.u.shf);
if (x.split)
subst_exstat = waitlast();
type = XBASE;
if (f & DOBLANK)
doblank--;
continue;
}
break;
}
/* check for end of word or IFS separation */
if (c == 0 || (!quote && (f & DOBLANK) && doblank &&
!make_magic && ctype(c, C_IFS))) {
/*-
* How words are broken up:
* | value of c
* word | ws nws 0
* -----------------------------------
* IFS_WORD w/WS w/NWS w
* IFS_WS -/WS -/NWS -
* IFS_NWS -/NWS w/NWS -
* IFS_IWS -/WS w/NWS -
* (w means generate a word)
*/
if ((word == IFS_WORD) || (word == IFS_QUOTE) || (c &&
(word == IFS_IWS || word == IFS_NWS) &&
!ctype(c, C_IFSWS))) {
emit_word:
if (f & DOHERESTR)
*dp++ = '\n';
*dp++ = '\0';
cp = Xclose(ds, dp);
if (fdo & DOBRACE)
/* also does globbing */
alt_expand(wp, cp, cp,
cp + Xlength(ds, (dp - 1)),
fdo | (f & DOMARKDIRS));
else if (fdo & DOGLOB)
glob(cp, wp, tobool(f & DOMARKDIRS));
else if ((f & DOPAT) || !(fdo & DOMAGIC))
XPput(*wp, cp);
else
XPput(*wp, debunk(cp, cp,
strlen(cp) + 1));
fdo = 0;
saw_eq = false;
/* must be 1/0 */
tilde_ok = (f & (DOTILDE | DOASNTILDE)) ? 1 : 0;
if (c == 0)
return;
Xinit(ds, dp, 128, ATEMP);
} else if (c == 0) {
return;
} else if (type == XSUB && ctype(c, C_IFS) &&
!ctype(c, C_IFSWS) && Xlength(ds, dp) == 0) {
*(cp = alloc(1, ATEMP)) = '\0';
XPput(*wp, cp);
type = XSUBMID;
}
if (word != IFS_NWS)
word = ctype(c, C_IFSWS) ? IFS_WS : IFS_NWS;
} else {
if (type == XSUB) {
if (word == IFS_NWS &&
Xlength(ds, dp) == 0) {
*(cp = alloc(1, ATEMP)) = '\0';
XPput(*wp, cp);
}
type = XSUBMID;
}
/* age tilde_ok info - ~ code tests second bit */
tilde_ok <<= 1;
/* mark any special second pass chars */
if (!quote)
switch (c) {
case '[':
case '!':
case '-':
case ']':
/*
* For character classes - doesn't hurt
* to have magic !,-,]s outside of
* [...] expressions.
*/
if (f & (DOPAT | DOGLOB)) {
fdo |= DOMAGIC;
if (c == '[')
fdo |= f & DOGLOB;
*dp++ = MAGIC;
}
break;
case '*':
case '?':
if (f & (DOPAT | DOGLOB)) {
fdo |= DOMAGIC | (f & DOGLOB);
*dp++ = MAGIC;
}
break;
case '{':
case '}':
case ',':
if ((f & DOBRACE) && (c == '{' /*}*/ ||
(fdo & DOBRACE))) {
fdo |= DOBRACE|DOMAGIC;
*dp++ = MAGIC;
}
break;
case '=':
/* Note first unquoted = for ~ */
if (!(f & DOTEMP) && (!Flag(FPOSIX) ||
(f & DOASNTILDE)) && !saw_eq) {
saw_eq = true;
tilde_ok = 1;
}
break;
case ':':
/* : */
/* Note unquoted : for ~ */
if (!(f & DOTEMP) && (f & DOASNTILDE))
tilde_ok = 1;
break;
case '~':
/*
* tilde_ok is reset whenever
* any of ' " $( $(( ${ } are seen.
* Note that tilde_ok must be preserved
* through the sequence ${A=a=}~
*/
if (type == XBASE &&
(f & (DOTILDE | DOASNTILDE)) &&
(tilde_ok & 2)) {
const char *tcp;
char *tdp = dp;
tcp = maybe_expand_tilde(sp,
&ds, &tdp,
tobool(f & DOASNTILDE));
if (tcp) {
if (dp != tdp)
word = IFS_WORD;
dp = tdp;
sp = tcp;
continue;
}
}
break;
}
else
/* undo temporary */
quote &= ~2;
if (make_magic) {
make_magic = false;
fdo |= DOMAGIC | (f & DOGLOB);
*dp++ = MAGIC;
} else if (ISMAGIC(c)) {
fdo |= DOMAGIC;
*dp++ = MAGIC;
}
/* save output char */
*dp++ = c;
word = IFS_WORD;
}
}
}
static bool
hasnonempty(const char **strv)
{
size_t i = 0;
while (strv[i])
if (*strv[i++])
return (true);
return (false);
}
/*
* Prepare to generate the string returned by ${} substitution.
*/
static int
varsub(Expand *xp, const char *sp, const char *word,
int *stypep, /* becomes qualifier type */
int *slenp) /* " " len (=, :=, etc.) valid iff *stypep != 0 */
{
int c;
int state; /* next state: XBASE, XARG, XSUB, XNULLSUB */
int stype; /* substitution type */
int slen;
const char *p;
struct tbl *vp;
bool zero_ok = false;
if ((stype = sp[0]) == '\0')
/* Bad variable name */
return (-1);
xp->var = NULL;
/*-
* ${#var}, string length (-U: characters, +U: octets) or array size
* ${%var}, string width (-U: screen columns, +U: octets)
*/
c = sp[1];
if (stype == '%' && c == '\0')
return (-1);
if ((stype == '#' || stype == '%') && c != '\0') {
/* Can't have any modifiers for ${#...} or ${%...} */
if (*word != CSUBST)
return (-1);
sp++;
/* Check for size of array */
if ((p = cstrchr(sp, '[')) && (p[1] == '*' || p[1] == '@') &&
p[2] == ']') {
int n = 0;
if (stype != '#')
return (-1);
vp = global(arrayname(sp));
if (vp->flag & (ISSET|ARRAY))
zero_ok = true;
for (; vp; vp = vp->u.array)
if (vp->flag & ISSET)
n++;
c = n;
} else if (c == '*' || c == '@') {
if (stype != '#')
return (-1);
c = e->loc->argc;
} else {
p = str_val(global(sp));
zero_ok = p != null;
if (stype == '#')
c = utflen(p);
else {
/* partial utf_mbswidth reimplementation */
const char *s = p;
unsigned int wc;
size_t len;
int cw;
c = 0;
while (*s) {
if (!UTFMODE || (len = utf_mbtowc(&wc,
s)) == (size_t)-1)
/* not UTFMODE or not UTF-8 */
wc = (unsigned char)(*s++);
else
/* UTFMODE and UTF-8 */
s += len;
/* wc == char or wchar at s++ */
if ((cw = utf_wcwidth(wc)) == -1) {
/* 646, 8859-1, 10646 C0/C1 */
c = -1;
break;
}
c += cw;
}
}
}
if (Flag(FNOUNSET) && c == 0 && !zero_ok)
errorf("%s: %s", sp, "parameter not set");
/* unqualified variable/string substitution */
*stypep = 0;
xp->str = shf_smprintf("%d", c);
return (XSUB);
}
/* Check for qualifiers in word part */
stype = 0;
c = word[slen = 0] == CHAR ? word[1] : 0;
if (c == ':') {
slen += 2;
stype = 0x80;
c = word[slen + 0] == CHAR ? word[slen + 1] : 0;
}
if (!stype && c == '/') {
slen += 2;
stype = c;
if (word[slen] == ADELIM) {
slen += 2;
stype |= 0x80;
}
} else if (stype == 0x80 && (c == ' ' || c == '0')) {
stype |= '0';
} else if (ctype(c, C_SUBOP1)) {
slen += 2;
stype |= c;
} else if (ctype(c, C_SUBOP2)) {
/* Note: ksh88 allows :%, :%%, etc */
slen += 2;
stype = c;
if (word[slen + 0] == CHAR && c == word[slen + 1]) {
stype |= 0x80;
slen += 2;
}
} else if (c == '@') {
/* @x where x is command char */
slen += 2;
stype |= 0x100;
if (word[slen] == CHAR) {
stype |= word[slen + 1];
slen += 2;
}
} else if (stype)
/* : is not ok */
return (-1);
if (!stype && *word != CSUBST)
return (-1);
*stypep = stype;
*slenp = slen;
c = sp[0];
if (c == '*' || c == '@') {
switch (stype & 0x17F) {
/* can't assign to a vector */
case '=':
/* can't trim a vector (yet) */
case '%':
case '#':
case '0':
case '/':
case 0x100 | '#':
case 0x100 | 'Q':
return (-1);
}
if (e->loc->argc == 0) {
xp->str = null;
xp->var = global(sp);
state = c == '@' ? XNULLSUB : XSUB;
} else {
xp->u.strv = (const char **)e->loc->argv + 1;
xp->str = *xp->u.strv++;
/* $@ */
xp->split = tobool(c == '@');
state = XARG;
}
/* POSIX 2009? */
zero_ok = true;
} else {
if ((p = cstrchr(sp, '[')) && (p[1] == '*' || p[1] == '@') &&
p[2] == ']') {
XPtrV wv;
switch (stype & 0x17F) {
/* can't assign to a vector */
case '=':
/* can't trim a vector (yet) */
case '%':
case '#':
case '?':
case '0':
case '/':
case 0x100 | '#':
case 0x100 | 'Q':
return (-1);
}
XPinit(wv, 32);
if ((c = sp[0]) == '!')
++sp;
vp = global(arrayname(sp));
for (; vp; vp = vp->u.array) {
if (!(vp->flag&ISSET))
continue;
XPput(wv, c == '!' ? shf_smprintf("%lu",
arrayindex(vp)) :
str_val(vp));
}
if (XPsize(wv) == 0) {
xp->str = null;
state = p[1] == '@' ? XNULLSUB : XSUB;
XPfree(wv);
} else {
XPput(wv, 0);
xp->u.strv = (const char **)XPptrv(wv);
xp->str = *xp->u.strv++;
/* ${foo[@]} */
xp->split = tobool(p[1] == '@');
state = XARG;
}
} else {
/* Can't assign things like $! or $1 */
if ((stype & 0x17F) == '=' &&
ctype(*sp, C_VAR1 | C_DIGIT))
return (-1);
if (*sp == '!' && sp[1]) {
++sp;
xp->var = global(sp);
if (vstrchr(sp, '['))
xp->str = shf_smprintf("%s[%lu]",
xp->var->name,
arrayindex(xp->var));
else
xp->str = xp->var->name;
} else {
xp->var = global(sp);
xp->str = str_val(xp->var);
}
state = XSUB;
}
}
c = stype & 0x7F;
/* test the compiler's code generator */
if (((stype < 0x100) && (ctype(c, C_SUBOP2) || c == '/' ||
(((stype & 0x80) ? *xp->str == '\0' : xp->str == null) &&
(state != XARG || (ifs0 || xp->split ?
(xp->u.strv[0] == NULL) : !hasnonempty(xp->u.strv))) ?
c == '=' || c == '-' || c == '?' : c == '+'))) ||
stype == (0x80 | '0') || stype == (0x100 | '#') ||
stype == (0x100 | 'Q'))
/* expand word instead of variable value */
state = XBASE;
if (Flag(FNOUNSET) && xp->str == null && !zero_ok &&
(ctype(c, C_SUBOP2) || (state != XBASE && c != '+')))
errorf("%s: %s", sp, "parameter not set");
return (state);
}
/*
* Run the command in $(...) and read its output.
*/
static int
comsub(Expand *xp, const char *cp, int fn MKSH_A_UNUSED)
{
Source *s, *sold;
struct op *t;
struct shf *shf;
uint8_t old_utfmode = UTFMODE;
s = pushs(SSTRING, ATEMP);
s->start = s->str = cp;
sold = source;
t = compile(s, true);
afree(s, ATEMP);
source = sold;
UTFMODE = old_utfmode;
if (t == NULL)
return (XBASE);
/* no waitlast() unless specifically enabled later */
xp->split = false;
if (t->type == TCOM &&
*t->args == NULL && *t->vars == NULL && t->ioact != NULL) {
/* $(<file) */
struct ioword *io = *t->ioact;
char *name;
if ((io->ioflag & IOTYPE) != IOREAD)
errorf("%s: %s", "funny $() command",
snptreef(NULL, 32, "%R", io));
shf = shf_open(name = evalstr(io->ioname, DOTILDE), O_RDONLY,
0, SHF_MAPHI | SHF_CLEXEC);
if (shf == NULL)
warningf(!Flag(FTALKING), "%s: %s %s: %s", name,
"can't open", "$(<...) input", cstrerror(errno));
} else if (fn == FUNSUB) {
int ofd1;
struct temp *tf = NULL;
/*
* create a temporary file, open for reading and writing,
* with an shf open for reading (buffered) but yet unused
*/
maketemp(ATEMP, TT_FUNSUB, &tf);
if (!tf->shf) {
errorf("can't %s temporary file %s: %s",
"create", tf->tffn, cstrerror(errno));
}
/* extract shf from temporary file, unlink and free it */
shf = tf->shf;
unlink(tf->tffn);
afree(tf, ATEMP);
/* save stdout and let it point to the tempfile */
ofd1 = savefd(1);
ksh_dup2(shf_fileno(shf), 1, false);
/*
* run tree, with output thrown into the tempfile,
* in a new function block
*/
valsub(t, NULL);
subst_exstat = exstat & 0xFF;
/* rewind the tempfile and restore regular stdout */
lseek(shf_fileno(shf), (off_t)0, SEEK_SET);
restfd(1, ofd1);
} else if (fn == VALSUB) {
xp->str = valsub(t, ATEMP);
subst_exstat = exstat & 0xFF;
return (XSUB);
} else {
int ofd1, pv[2];
openpipe(pv);
shf = shf_fdopen(pv[0], SHF_RD, NULL);
ofd1 = savefd(1);
if (pv[1] != 1) {
ksh_dup2(pv[1], 1, false);
close(pv[1]);
}
execute(t, XXCOM | XPIPEO | XFORK, NULL);
restfd(1, ofd1);
startlast();
/* waitlast() */
xp->split = true;
}
xp->u.shf = shf;
return (XCOM);
}
/*
* perform #pattern and %pattern substitution in ${}
*/
static char *
trimsub(char *str, char *pat, int how)
{
char *end = strnul(str);
char *p, c;
switch (how & 0xFF) {
case '#':
/* shortest match at beginning */
for (p = str; p <= end; p += utf_ptradj(p)) {
c = *p; *p = '\0';
if (gmatchx(str, pat, false)) {
*p = c;
return (p);
}
*p = c;
}
break;
case '#'|0x80:
/* longest match at beginning */
for (p = end; p >= str; p--) {
c = *p; *p = '\0';
if (gmatchx(str, pat, false)) {
*p = c;
return (p);
}
*p = c;
}
break;
case '%':
/* shortest match at end */
p = end;
while (p >= str) {
if (gmatchx(p, pat, false))
goto trimsub_match;
if (UTFMODE) {
char *op = p;
while ((p-- > str) && ((*p & 0xC0) == 0x80))
;
if ((p < str) || (p + utf_ptradj(p) != op))
p = op - 1;
} else
--p;
}
break;
case '%'|0x80:
/* longest match at end */
for (p = str; p <= end; p++)
if (gmatchx(p, pat, false)) {
trimsub_match:
strndupx(end, str, p - str, ATEMP);
return (end);
}
break;
}
/* no match, return string */
return (str);
}
/*
* glob
* Name derived from V6's /etc/glob, the program that expanded filenames.
*/
/* XXX cp not const 'cause slashes are temporarily replaced with NULs... */
static void
glob(char *cp, XPtrV *wp, bool markdirs)
{
int oldsize = XPsize(*wp);
if (glob_str(cp, wp, markdirs) == 0)
XPput(*wp, debunk(cp, cp, strlen(cp) + 1));
else
qsort(XPptrv(*wp) + oldsize, XPsize(*wp) - oldsize,
sizeof(void *), xstrcmp);
}
#define GF_NONE 0
#define GF_EXCHECK BIT(0) /* do existence check on file */
#define GF_GLOBBED BIT(1) /* some globbing has been done */
#define GF_MARKDIR BIT(2) /* add trailing / to directories */
/*
* Apply file globbing to cp and store the matching files in wp. Returns
* the number of matches found.
*/
int
glob_str(char *cp, XPtrV *wp, bool markdirs)
{
int oldsize = XPsize(*wp);
XString xs;
char *xp;
Xinit(xs, xp, 256, ATEMP);
globit(&xs, &xp, cp, wp, markdirs ? GF_MARKDIR : GF_NONE);
Xfree(xs, xp);
return (XPsize(*wp) - oldsize);
}
static void
globit(XString *xs, /* dest string */
char **xpp, /* ptr to dest end */
char *sp, /* source path */
XPtrV *wp, /* output list */
int check) /* GF_* flags */
{
char *np; /* next source component */
char *xp = *xpp;
char *se;
char odirsep;
/* This to allow long expansions to be interrupted */
intrcheck();
if (sp == NULL) {
/* end of source path */
/*
* We only need to check if the file exists if a pattern
* is followed by a non-pattern (eg, foo*x/bar; no check
* is needed for foo* since the match must exist) or if
* any patterns were expanded and the markdirs option is set.
* Symlinks make things a bit tricky...
*/
if ((check & GF_EXCHECK) ||
((check & GF_MARKDIR) && (check & GF_GLOBBED))) {
#define stat_check() (stat_done ? stat_done : (stat_done = \
stat(Xstring(*xs, xp), &statb) < 0 ? -1 : 1))
struct stat lstatb, statb;
/* -1: failed, 1 ok, 0 not yet done */
int stat_done = 0;
if (mksh_lstat(Xstring(*xs, xp), &lstatb) < 0)
return;
/*
* special case for systems which strip trailing
* slashes from regular files (eg, /etc/passwd/).
* SunOS 4.1.3 does this...
*/
if ((check & GF_EXCHECK) && xp > Xstring(*xs, xp) &&
xp[-1] == '/' && !S_ISDIR(lstatb.st_mode) &&
(!S_ISLNK(lstatb.st_mode) ||
stat_check() < 0 || !S_ISDIR(statb.st_mode)))
return;
/*
* Possibly tack on a trailing / if there isn't already
* one and if the file is a directory or a symlink to a
* directory
*/
if (((check & GF_MARKDIR) && (check & GF_GLOBBED)) &&
xp > Xstring(*xs, xp) && xp[-1] != '/' &&
(S_ISDIR(lstatb.st_mode) ||
(S_ISLNK(lstatb.st_mode) && stat_check() > 0 &&
S_ISDIR(statb.st_mode)))) {
*xp++ = '/';
*xp = '\0';
}
}
strndupx(np, Xstring(*xs, xp), Xlength(*xs, xp), ATEMP);
XPput(*wp, np);
return;
}
if (xp > Xstring(*xs, xp))
*xp++ = '/';
while (*sp == '/') {
Xcheck(*xs, xp);
*xp++ = *sp++;
}
np = strchr(sp, '/');
if (np != NULL) {
se = np;
/* don't assume '/', can be multiple kinds */
odirsep = *np;
*np++ = '\0';
} else {
odirsep = '\0'; /* keep gcc quiet */
se = sp + strlen(sp);
}
/*
* Check if sp needs globbing - done to avoid pattern checks for strings
* containing MAGIC characters, open [s without the matching close ],
* etc. (otherwise opendir() will be called which may fail because the
* directory isn't readable - if no globbing is needed, only execute
* permission should be required (as per POSIX)).
*/
if (!has_globbing(sp, se)) {
XcheckN(*xs, xp, se - sp + 1);
debunk(xp, sp, Xnleft(*xs, xp));
xp += strlen(xp);
*xpp = xp;
globit(xs, xpp, np, wp, check);
} else {
DIR *dirp;
struct dirent *d;
char *name;
size_t len, prefix_len;
/* xp = *xpp; copy_non_glob() may have re-alloc'd xs */
*xp = '\0';
prefix_len = Xlength(*xs, xp);
dirp = opendir(prefix_len ? Xstring(*xs, xp) : ".");
if (dirp == NULL)
goto Nodir;
while ((d = readdir(dirp)) != NULL) {
name = d->d_name;
if (name[0] == '.' &&
(name[1] == 0 || (name[1] == '.' && name[2] == 0)))
/* always ignore . and .. */
continue;
if ((*name == '.' && *sp != '.') ||
!gmatchx(name, sp, true))
continue;
len = strlen(d->d_name) + 1;
XcheckN(*xs, xp, len);
memcpy(xp, name, len);
*xpp = xp + len - 1;
globit(xs, xpp, np, wp,
(check & GF_MARKDIR) | GF_GLOBBED
| (np ? GF_EXCHECK : GF_NONE));
xp = Xstring(*xs, xp) + prefix_len;
}
closedir(dirp);
Nodir:
;
}
if (np != NULL)
*--np = odirsep;
}
/* remove MAGIC from string */
char *
debunk(char *dp, const char *sp, size_t dlen)
{
char *d;
const char *s;
if ((s = cstrchr(sp, MAGIC))) {
if (s - sp >= (ssize_t)dlen)
return (dp);
memmove(dp, sp, s - sp);
for (d = dp + (s - sp); *s && (d - dp < (ssize_t)dlen); s++)
if (!ISMAGIC(*s) || !(*++s & 0x80) ||
!vstrchr("*+?@! ", *s & 0x7f))
*d++ = *s;
else {
/* extended pattern operators: *+?@! */
if ((*s & 0x7f) != ' ')
*d++ = *s & 0x7f;
if (d - dp < (ssize_t)dlen)
*d++ = '(';
}
*d = '\0';
} else if (dp != sp)
strlcpy(dp, sp, dlen);
return (dp);
}
/*
* Check if p is an unquoted name, possibly followed by a / or :. If so
* puts the expanded version in *dcp,dp and returns a pointer in p just
* past the name, otherwise returns 0.
*/
static const char *
maybe_expand_tilde(const char *p, XString *dsp, char **dpp, bool isassign)
{
XString ts;
char *dp = *dpp;
char *tp;
const char *r;
Xinit(ts, tp, 16, ATEMP);
/* : only for DOASNTILDE form */
while (p[0] == CHAR && p[1] != '/' && (!isassign || p[1] != ':'))
{
Xcheck(ts, tp);
*tp++ = p[1];
p += 2;
}
*tp = '\0';
r = (p[0] == EOS || p[0] == CHAR || p[0] == CSUBST) ?
do_tilde(Xstring(ts, tp)) : NULL;
Xfree(ts, tp);
if (r) {
while (*r) {
Xcheck(*dsp, dp);
if (ISMAGIC(*r))
*dp++ = MAGIC;
*dp++ = *r++;
}
*dpp = dp;
r = p;
}
return (r);
}
/*
* tilde expansion
*
* based on a version by Arnold Robbins
*/
char *
do_tilde(char *cp)
{
char *dp = null;
if (cp[0] == '\0')
dp = str_val(global("HOME"));
else if (cp[0] == '+' && cp[1] == '\0')
dp = str_val(global("PWD"));
else if (ksh_isdash(cp))
dp = str_val(global("OLDPWD"));
#ifndef MKSH_NOPWNAM
else
dp = homedir(cp);
#endif
/* If HOME, PWD or OLDPWD are not set, don't expand ~ */
return (dp == null ? NULL : dp);
}
#ifndef MKSH_NOPWNAM
/*
* map userid to user's home directory.
* note that 4.3's getpw adds more than 6K to the shell,
* and the YP version probably adds much more.
* we might consider our own version of getpwnam() to keep the size down.
*/
static char *
homedir(char *name)
{
struct tbl *ap;
ap = ktenter(&homedirs, name, hash(name));
if (!(ap->flag & ISSET)) {
struct passwd *pw;
pw = getpwnam(name);
if (pw == NULL)
return (NULL);
strdupx(ap->val.s, pw->pw_dir, APERM);
ap->flag |= DEFINED|ISSET|ALLOC;
}
return (ap->val.s);
}
#endif
static void
alt_expand(XPtrV *wp, char *start, char *exp_start, char *end, int fdo)
{
unsigned int count = 0;
char *brace_start, *brace_end, *comma = NULL;
char *field_start;
char *p = exp_start;
/* search for open brace */
while ((p = strchr(p, MAGIC)) && p[1] != '{' /*}*/)
p += 2;
brace_start = p;
/* find matching close brace, if any */
if (p) {
comma = NULL;
count = 1;
p += 2;
while (*p && count) {
if (ISMAGIC(*p++)) {
if (*p == '{' /*}*/)
++count;
else if (*p == /*{*/ '}')
--count;
else if (*p == ',' && count == 1)
comma = p;
++p;
}
}
}
/* no valid expansions... */
if (!p || count != 0) {
/*
* Note that given a{{b,c} we do not expand anything (this is
* what AT&T ksh does. This may be changed to do the {b,c}
* expansion. }
*/
if (fdo & DOGLOB)
glob(start, wp, tobool(fdo & DOMARKDIRS));
else
XPput(*wp, debunk(start, start, end - start));
return;
}
brace_end = p;
if (!comma) {
alt_expand(wp, start, brace_end, end, fdo);
return;
}
/* expand expression */
field_start = brace_start + 2;
count = 1;
for (p = brace_start + 2; p != brace_end; p++) {
if (ISMAGIC(*p)) {
if (*++p == '{' /*}*/)
++count;
else if ((*p == /*{*/ '}' && --count == 0) ||
(*p == ',' && count == 1)) {
char *news;
int l1, l2, l3;
/*
* addition safe since these operate on
* one string (separate substrings)
*/
l1 = brace_start - start;
l2 = (p - 1) - field_start;
l3 = end - brace_end;
news = alloc(l1 + l2 + l3 + 1, ATEMP);
memcpy(news, start, l1);
memcpy(news + l1, field_start, l2);
memcpy(news + l1 + l2, brace_end, l3);
news[l1 + l2 + l3] = '\0';
alt_expand(wp, news, news + l1,
news + l1 + l2 + l3, fdo);
field_start = p + 1;
}
}
}
return;
}
/* helper function due to setjmp/longjmp woes */
static char *
valsub(struct op *t, Area *ap)
{
char * volatile cp = NULL;
struct tbl * volatile vp = NULL;
newenv(E_FUNC);
newblock();
if (ap)
vp = local("REPLY", false);
if (!kshsetjmp(e->jbuf))
execute(t, XXCOM | XERROK, NULL);
if (vp)
strdupx(cp, str_val(vp), ap);
quitenv(NULL);
return (cp);
}
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