/*
* Perform parameter expansion, command substitution and arithmetic
* expansion, and tilde expansion if requested via EXP_TILDE/EXP_VARTILDE.
* Processing ends at a CTLENDVAR or CTLENDARI character as well as '\0'.
* This is used to expand word in ${var+word} etc.
* If EXP_FULL or EXP_CASE are set, keep and/or generate CTLESC
* characters to allow for further processing.
* If EXP_FULL is set, also preserve CTLQUOTEMARK characters.
*/
static char *
argstr(char *p, int flag)
{
char c;
int quotes = flag & (EXP_FULL | EXP_CASE); /* do CTLESC */
int firsteq = 1;
int split_lit;
int lit_quoted;
split_lit = flag & EXP_SPLIT_LIT;
lit_quoted = flag & EXP_LIT_QUOTED;
flag &= ~(EXP_SPLIT_LIT | EXP_LIT_QUOTED);
if (*p == '~' && (flag & (EXP_TILDE | EXP_VARTILDE)))
p = exptilde(p, flag);
for (;;) {
CHECKSTRSPACE(2, expdest);
switch (c = *p++) {
case '\0':
return (p - 1);
case CTLENDVAR:
case CTLENDARI:
return (p);
case CTLQUOTEMARK:
lit_quoted = 1;
/* "$@" syntax adherence hack */
if (p[0] == CTLVAR && p[2] == '@' && p[3] == '=')
break;
if ((flag & EXP_FULL) != 0)
USTPUTC(c, expdest);
break;
case CTLQUOTEEND:
lit_quoted = 0;
break;
case CTLESC:
if (quotes)
USTPUTC(c, expdest);
c = *p++;
USTPUTC(c, expdest);
if (split_lit && !lit_quoted)
recordregion(expdest - stackblock() -
(quotes ? 2 : 1),
expdest - stackblock(), 0);
break;
case CTLVAR:
p = evalvar(p, flag);
break;
case CTLBACKQ:
case CTLBACKQ|CTLQUOTE:
expbackq(argbackq->n, c & CTLQUOTE, flag);
argbackq = argbackq->next;
break;
case CTLARI:
p = expari(p);
break;
case ':':
case '=':
/*
* sort of a hack - expand tildes in variable
* assignments (after the first '=' and after ':'s).
*/
USTPUTC(c, expdest);
if (split_lit && !lit_quoted)
recordregion(expdest - stackblock() - 1,
expdest - stackblock(), 0);
if (flag & EXP_VARTILDE && *p == '~' &&
(c != '=' || firsteq)) {
if (c == '=')
firsteq = 0;
p = exptilde(p, flag);
}
break;
default:
USTPUTC(c, expdest);
if (split_lit && !lit_quoted)
recordregion(expdest - stackblock() - 1,
expdest - stackblock(), 0);
}
}
}
/*
* Perform command substitution.
*/
static void
expbackq(union node *cmd, int quoted, int flag, struct worddest *dst)
{
struct backcmd in;
int i;
char buf[128];
char *p;
char *dest = expdest;
struct nodelist *saveargbackq;
char lastc;
char const *syntax = quoted? DQSYNTAX : BASESYNTAX;
int quotes = flag & (EXP_GLOB | EXP_CASE);
size_t nnl;
const char *ifs;
INTOFF;
saveargbackq = argbackq;
p = grabstackstr(dest);
evalbackcmd(cmd, &in);
ungrabstackstr(p, dest);
argbackq = saveargbackq;
p = in.buf;
nnl = 0;
if (!quoted && flag & EXP_SPLIT)
ifs = ifsset() ? ifsval() : " \t\n";
else
ifs = "";
/* Don't copy trailing newlines */
for (;;) {
if (--in.nleft < 0) {
if (in.fd < 0)
break;
while ((i = read(in.fd, buf, sizeof buf)) < 0 && errno == EINTR);
TRACE(("expbackq: read returns %d\n", i));
if (i <= 0)
break;
p = buf;
in.nleft = i - 1;
}
lastc = *p++;
if (lastc == '\0')
continue;
if (lastc == '\n') {
nnl++;
} else {
if (nnl > 0) {
if (strchr(ifs, '\n') != NULL) {
NEXTWORD('\n', flag, dest, dst);
nnl = 0;
} else {
CHECKSTRSPACE(nnl + 2, dest);
while (nnl > 0) {
nnl--;
USTPUTC('\n', dest);
}
}
}
if (strchr(ifs, lastc) != NULL)
NEXTWORD(lastc, flag, dest, dst);
else {
CHECKSTRSPACE(2, dest);
if (quotes && syntax[(int)lastc] == CCTL)
USTPUTC(CTLESC, dest);
USTPUTC(lastc, dest);
}
}
}
if (in.fd >= 0)
close(in.fd);
if (in.buf)
ckfree(in.buf);
if (in.jp)
exitstatus = waitforjob(in.jp, (int *)NULL);
TRACE(("expbackq: size=%td: \"%.*s\"\n",
((dest - stackblock()) - startloc),
(int)((dest - stackblock()) - startloc),
stackblock() + startloc));
expdest = dest;
INTON;
}
/*
* Perform command substitution.
*/
static void
expbackq(union node *cmd, int quoted, int flag)
{
struct backcmd in;
int i;
char buf[128];
char *p;
char *dest = expdest;
struct ifsregion saveifs, *savelastp;
struct nodelist *saveargbackq;
char lastc;
int startloc = dest - stackblock();
char const *syntax = quoted? DQSYNTAX : BASESYNTAX;
int quotes = flag & (EXP_FULL | EXP_CASE);
size_t nnl;
INTOFF;
saveifs = ifsfirst;
savelastp = ifslastp;
saveargbackq = argbackq;
p = grabstackstr(dest);
evalbackcmd(cmd, &in);
ungrabstackstr(p, dest);
ifsfirst = saveifs;
ifslastp = savelastp;
argbackq = saveargbackq;
p = in.buf;
lastc = '\0';
nnl = 0;
/* Don't copy trailing newlines */
for (;;) {
if (--in.nleft < 0) {
if (in.fd < 0)
break;
while ((i = read(in.fd, buf, sizeof buf)) < 0 && errno == EINTR);
TRACE(("expbackq: read returns %d\n", i));
if (i <= 0)
break;
p = buf;
in.nleft = i - 1;
}
lastc = *p++;
if (lastc != '\0') {
if (lastc == '\n') {
nnl++;
} else {
CHECKSTRSPACE(nnl + 2, dest);
while (nnl > 0) {
nnl--;
USTPUTC('\n', dest);
}
if (quotes && syntax[(int)lastc] == CCTL)
USTPUTC(CTLESC, dest);
USTPUTC(lastc, dest);
}
}
}
if (in.fd >= 0)
close(in.fd);
if (in.buf)
ckfree(in.buf);
if (in.jp)
exitstatus = waitforjob(in.jp, (int *)NULL);
if (quoted == 0)
recordregion(startloc, dest - stackblock(), 0);
TRACE(("expbackq: size=%td: \"%.*s\"\n",
((dest - stackblock()) - startloc),
(int)((dest - stackblock()) - startloc),
stackblock() + startloc));
expdest = dest;
INTON;
}
/*
* Perform parameter expansion, command substitution and arithmetic
* expansion, and tilde expansion if requested via EXP_TILDE/EXP_VARTILDE.
* Processing ends at a CTLENDVAR or CTLENDARI character as well as '\0'.
* This is used to expand word in ${var+word} etc.
* If EXP_GLOB or EXP_CASE are set, keep and/or generate CTLESC
* characters to allow for further processing.
*
* If EXP_SPLIT is set, dst receives any complete words produced.
*/
static const char *
argstr(const char *p, int flag, struct worddest *dst)
{
char c;
int quotes = flag & (EXP_GLOB | EXP_CASE); /* do CTLESC */
int firsteq = 1;
int split_lit;
int lit_quoted;
split_lit = flag & EXP_SPLIT_LIT;
lit_quoted = flag & EXP_LIT_QUOTED;
flag &= ~(EXP_SPLIT_LIT | EXP_LIT_QUOTED);
if (*p == '~' && (flag & (EXP_TILDE | EXP_VARTILDE)))
p = exptilde(p, flag);
for (;;) {
CHECKSTRSPACE(2, expdest);
switch (c = *p++) {
case '\0':
return (p - 1);
case CTLENDVAR:
case CTLENDARI:
return (p);
case CTLQUOTEMARK:
lit_quoted = 1;
/* "$@" syntax adherence hack */
if (p[0] == CTLVAR && (p[1] & VSQUOTE) != 0 &&
p[2] == '@' && p[3] == '=')
break;
if ((flag & EXP_SPLIT) != 0 && expdest == stackblock())
dst->state = WORD_QUOTEMARK;
break;
case CTLQUOTEEND:
lit_quoted = 0;
break;
case CTLESC:
c = *p++;
if (split_lit && !lit_quoted &&
strchr(ifsset() ? ifsval() : " \t\n", c) != NULL) {
NEXTWORD(c, flag, expdest, dst);
break;
}
if (quotes)
USTPUTC(CTLESC, expdest);
USTPUTC(c, expdest);
break;
case CTLVAR:
p = evalvar(p, flag, dst);
break;
case CTLBACKQ:
case CTLBACKQ|CTLQUOTE:
expbackq(argbackq->n, c & CTLQUOTE, flag, dst);
argbackq = argbackq->next;
break;
case CTLARI:
p = expari(p, flag, dst);
break;
case ':':
case '=':
/*
* sort of a hack - expand tildes in variable
* assignments (after the first '=' and after ':'s).
*/
if (split_lit && !lit_quoted &&
strchr(ifsset() ? ifsval() : " \t\n", c) != NULL) {
NEXTWORD(c, flag, expdest, dst);
break;
}
USTPUTC(c, expdest);
if (flag & EXP_VARTILDE && *p == '~' &&
(c != '=' || firsteq)) {
if (c == '=')
firsteq = 0;
p = exptilde(p, flag);
}
break;
default:
if (split_lit && !lit_quoted &&
strchr(ifsset() ? ifsval() : " \t\n", c) != NULL) {
NEXTWORD(c, flag, expdest, dst);
break;
}
USTPUTC(c, expdest);
}
}
}
