Exemplo n.º 1
0
/*
 * Process here documents by providing the content, either as
 * result (globally allocated) string or in a temp file; if
 * unquoted, the string is expanded first.
 */
static int
hereinval(const char *content, int sub, char **resbuf, struct shf *shf)
{
	const char * volatile ccp = content;
	struct source *s, *osource;

	osource = source;
	newenv(E_ERRH);
	if (kshsetjmp(e->jbuf)) {
		source = osource;
		quitenv(shf);
		/* special to iosetup(): don't print error */
		return (-2);
	}
	if (sub) {
		/* do substitutions on the content of heredoc */
		s = pushs(SSTRING, ATEMP);
		s->start = s->str = ccp;
		source = s;
		if (yylex(sub) != LWORD)
			internal_errorf("%s: %s", "herein", "yylex");
		source = osource;
		ccp = evalstr(yylval.cp, 0);
	}

	if (resbuf == NULL)
		shf_puts(ccp, shf);
	else
		strdupx(*resbuf, ccp, APERM);

	quitenv(NULL);
	return (0);
}
Exemplo n.º 2
0
void
set_prompt(int to, Source *s)
{
	char *ps1;
	Area *saved_atemp;

	cur_prompt = to;

	switch (to) {
	case PS1: /* command */
		ps1 = str_save(str_val(global("PS1")), ATEMP);
		saved_atemp = ATEMP;	/* ps1 is freed by substitute() */
		newenv(E_ERRH);
		if (_setjmp(e->jbuf)) {
			prompt = safe_prompt;
			/* Don't print an error - assume it has already
			 * been printed.  Reason is we may have forked
			 * to run a command and the child may be
			 * unwinding its stack through this code as it
			 * exits.
			 */
		} else
			prompt = str_save(substitute(ps1, 0),
					 saved_atemp);
		quitenv(NULL);
		break;
	case PS2: /* command continuation */
		prompt = str_val(global("PS2"));
		break;
	}
}
Exemplo n.º 3
0
/* note: i MUST NOT be 0 */
void
unwind(int i)
{
	/*
	 * This is a kludge. We need to restore everything that was
	 * changed in the new environment, see cid 1005090337C7A669439
	 * and 10050903386452ACBF1, but fail to even save things most of
	 * the time. funcs.c:c_eval() changes FERREXIT temporarily to 0,
	 * which needs to be restored thus (related to Debian #696823).
	 * We did not save the shell flags, so we use a special or'd
	 * value here... this is mostly to clean up behind *other*
	 * callers of unwind(LERROR) here; exec.c has the regular case.
	 */
	if (Flag(FERREXIT) & 0x80) {
		/* GNU bash does not run this trapsig */
		trapsig(ksh_SIGERR);
		Flag(FERREXIT) &= ~0x80;
	}

	/* ordering for EXIT vs ERR is a bit odd (this is what AT&T ksh does) */
	if (i == LEXIT || ((i == LERROR || i == LINTR) &&
	    sigtraps[ksh_SIGEXIT].trap &&
	    (!Flag(FTALKING) || Flag(FERREXIT)))) {
		++trap_nested;
		runtrap(&sigtraps[ksh_SIGEXIT], trap_nested == 1);
		--trap_nested;
		i = LLEAVE;
	} else if (Flag(FERREXIT) == 1 && (i == LERROR || i == LINTR)) {
		++trap_nested;
		runtrap(&sigtraps[ksh_SIGERR], trap_nested == 1);
		--trap_nested;
		i = LLEAVE;
	}

	while (/* CONSTCOND */ 1) {
		switch (e->type) {
		case E_PARSE:
		case E_FUNC:
		case E_INCL:
		case E_LOOP:
		case E_ERRH:
			kshlongjmp(e->jbuf, i);
			/* NOTREACHED */
		case E_NONE:
			if (i == LINTR)
				e->flags |= EF_FAKE_SIGDIE;
			/* FALLTHROUGH */
		default:
			quitenv(NULL);
			/*
			 * quitenv() may have reclaimed the memory
			 * used by source which will end badly when
			 * we jump to a function that expects it to
			 * be valid
			 */
			source = NULL;
		}
	}
}
Exemplo n.º 4
0
void
set_prompt(int to, Source *s)
{
	cur_prompt = (uint8_t)to;

	switch (to) {
	/* command */
	case PS1:
		/*
		 * Substitute ! and !! here, before substitutions are done
		 * so ! in expanded variables are not expanded.
		 * NOTE: this is not what AT&T ksh does (it does it after
		 * substitutions, POSIX doesn't say which is to be done.
		 */
		{
			struct shf *shf;
			char * volatile ps1;
			Area *saved_atemp;
			int saved_lineno;

			ps1 = str_val(global("PS1"));
			shf = shf_sopen(NULL, strlen(ps1) * 2,
			    SHF_WR | SHF_DYNAMIC, NULL);
			while (*ps1)
				if (*ps1 != '!' || *++ps1 == '!')
					shf_putchar(*ps1++, shf);
				else
					shf_fprintf(shf, "%lu", s ?
					    (unsigned long)s->line + 1 : 0UL);
			ps1 = shf_sclose(shf);
			saved_lineno = current_lineno;
			if (s)
				current_lineno = s->line + 1;
			saved_atemp = ATEMP;
			newenv(E_ERRH);
			if (kshsetjmp(e->jbuf)) {
				prompt = safe_prompt;
				/*
				 * Don't print an error - assume it has already
				 * been printed. Reason is we may have forked
				 * to run a command and the child may be
				 * unwinding its stack through this code as it
				 * exits.
				 */
			} else {
				char *cp = substitute(ps1, 0);
				strdupx(prompt, cp, saved_atemp);
			}
			current_lineno = saved_lineno;
			quitenv(NULL);
		}
		break;
	/* command continuation */
	case PS2:
		prompt = str_val(global("PS2"));
		break;
	}
}
Exemplo n.º 5
0
Arquivo: c_sh.c Projeto: tomgrean/kash
int
c_exitreturn(char **wp)
{
	int how = LEXIT;
	int n;
	char *arg;

	if (!Flag(FPOSIX) 			// not posix
	    && *wp && *(wp + 1) && !*(wp + 2))  // only one argument passed
		arg=*(wp + 1);		        // code regardless of starting with '-' or not
	else {
		if (ksh_getopt(wp, &builtin_opt, null) == '?')
			return 1;
		arg = wp[builtin_opt.optind];
	}

	if (arg) {
	    if (!getn(arg, &n)) {
		    exstat = 1;
		    warningf(true, "%s: bad number", arg);
	    } else
		    exstat = n;
	}
	if (wp[0][0] == 'r') { /* return */
		struct env *ep;

		/* need to tell if this is exit or return so trap exit will
		 * work right (POSIX)
		 */
		for (ep = e; ep; ep = ep->oenv)
			if (STOP_RETURN(ep->type)) {
				how = LRETURN;
				break;
			}
	}

	if (how == LEXIT && !really_exit && j_stopped_running()) {
		really_exit = 1;
		how = LSHELL;
	}

	quitenv();	/* get rid of any i/o redirections */
	unwind(how);
	/*NOTREACHED*/
	return 0;
}
Exemplo n.º 6
0
int
c_exitreturn(char **wp)
{
	int how = LEXIT;
	int n;
	char *arg;

	if (ksh_getopt(wp, &builtin_opt, null) == '?')
		return 1;
	arg = wp[builtin_opt.optind];

	if (arg) {
		if (!getn(arg, &n)) {
			exstat = 1;
			warningf(true, "%s: bad number", arg);
		} else
			exstat = n;
	}
	if (wp[0][0] == 'r') { /* return */
		struct env *ep;

		/* need to tell if this is exit or return so trap exit will
		 * work right (POSIX)
		 */
		for (ep = e; ep; ep = ep->oenv)
			if (STOP_RETURN(ep->type)) {
				how = LRETURN;
				break;
			}
	}

	if (how == LEXIT && !really_exit && j_stopped_running()) {
		really_exit = 1;
		how = LSHELL;
	}

	quitenv(NULL);	/* get rid of any i/o redirections */
	unwind(how);
	/* NOTREACHED */
	return 0;
}
Exemplo n.º 7
0
static int
comexec(struct op *t, struct tbl * volatile tp, const char **ap,
    volatile int flags, volatile int *xerrok)
{
	int i;
	volatile int rv = 0;
	const char *cp;
	const char **lastp;
	/* Must be static (XXX but why?) */
	static struct op texec;
	int type_flags;
	bool keepasn_ok;
	int fcflags = FC_BI|FC_FUNC|FC_PATH;
	bool bourne_function_call = false;
	struct block *l_expand, *l_assign;

	/*
	 * snag the last argument for $_ XXX not the same as AT&T ksh,
	 * which only seems to set $_ after a newline (but not in
	 * functions/dot scripts, but in interactive and script) -
	 * perhaps save last arg here and set it in shell()?.
	 */
	if (Flag(FTALKING) && *(lastp = ap)) {
		while (*++lastp)
			;
		/* setstr() can't fail here */
		setstr(typeset("_", LOCAL, 0, INTEGER, 0), *--lastp,
		    KSH_RETURN_ERROR);
	}

	/**
	 * Deal with the shell builtins builtin, exec and command since
	 * they can be followed by other commands. This must be done before
	 * we know if we should create a local block which must be done
	 * before we can do a path search (in case the assignments change
	 * PATH).
	 * Odd cases:
	 *	FOO=bar exec >/dev/null		FOO is kept but not exported
	 *	FOO=bar exec foobar		FOO is exported
	 *	FOO=bar command exec >/dev/null	FOO is neither kept nor exported
	 *	FOO=bar command			FOO is neither kept nor exported
	 *	PATH=... foobar			use new PATH in foobar search
	 */
	keepasn_ok = true;
	while (tp && tp->type == CSHELL) {
		/* undo effects of command */
		fcflags = FC_BI|FC_FUNC|FC_PATH;
		if (tp->val.f == c_builtin) {
			if ((cp = *++ap) == NULL ||
			    (!strcmp(cp, "--") && (cp = *++ap) == NULL)) {
				tp = NULL;
				break;
			}
			if ((tp = findcom(cp, FC_BI)) == NULL)
				errorf("%s: %s: %s", Tbuiltin, cp, "not a builtin");
			continue;
		} else if (tp->val.f == c_exec) {
			if (ap[1] == NULL)
				break;
			ap++;
			flags |= XEXEC;
		} else if (tp->val.f == c_command) {
			int optc, saw_p = 0;

			/*
			 * Ugly dealing with options in two places (here
			 * and in c_command(), but such is life)
			 */
			ksh_getopt_reset(&builtin_opt, 0);
			while ((optc = ksh_getopt(ap, &builtin_opt, ":p")) == 'p')
				saw_p = 1;
			if (optc != EOF)
				/* command -vV or something */
				break;
			/* don't look for functions */
			fcflags = FC_BI|FC_PATH;
			if (saw_p) {
				if (Flag(FRESTRICTED)) {
					warningf(true, "%s: %s",
					    "command -p", "restricted");
					rv = 1;
					goto Leave;
				}
				fcflags |= FC_DEFPATH;
			}
			ap += builtin_opt.optind;
			/*
			 * POSIX says special builtins lose their status
			 * if accessed using command.
			 */
			keepasn_ok = false;
			if (!ap[0]) {
				/* ensure command with no args exits with 0 */
				subst_exstat = 0;
				break;
			}
#ifndef MKSH_NO_EXTERNAL_CAT
		} else if (tp->val.f == c_cat) {
			/*
			 * if we have any flags, do not use the builtin
			 * in theory, we could allow -u, but that would
			 * mean to use ksh_getopt here and possibly ad-
			 * ded complexity and more code and isn't worth
			 * additional hassle (and the builtin must call
			 * ksh_getopt already but can't come back here)
			 */
			if (ap[1] && ap[1][0] == '-' && ap[1][1] != '\0' &&
			    /* argument, begins with -, is not - or -- */
			    (ap[1][1] != '-' || ap[1][2] != '\0'))
				/* don't look for builtins or functions */
				fcflags = FC_PATH;
			else
				/* go on, use the builtin */
				break;
#endif
#if !defined(MKSH_SMALL)
		} else if (tp->val.f == c_trap) {
			t->u.evalflags &= ~DOTCOMEXEC;
			break;
#endif
		} else
			break;
		tp = findcom(ap[0], fcflags & (FC_BI|FC_FUNC));
	}
#if !defined(MKSH_SMALL)
	if (t->u.evalflags & DOTCOMEXEC)
		flags |= XEXEC;
#endif
	l_expand = e->loc;
	if (keepasn_ok && (!ap[0] || (tp && (tp->flag & KEEPASN))))
		type_flags = 0;
	else {
		/* create new variable/function block */
		newblock();
		/* ksh functions don't keep assignments, POSIX functions do. */
		if (keepasn_ok && tp && tp->type == CFUNC &&
		    !(tp->flag & FKSH)) {
			bourne_function_call = true;
			type_flags = EXPORT;
		} else
			type_flags = LOCAL|LOCAL_COPY|EXPORT;
	}
	l_assign = e->loc;
	if (Flag(FEXPORT))
		type_flags |= EXPORT;
	for (i = 0; t->vars[i]; i++) {
		/* do NOT lookup in the new var/fn block just created */
		e->loc = l_expand;
		cp = evalstr(t->vars[i], DOASNTILDE);
		e->loc = l_assign;
		/* but assign in there as usual */

		if (Flag(FXTRACE)) {
			if (i == 0)
				shf_puts(substitute(str_val(global("PS4")), 0),
				    shl_out);
			shf_fprintf(shl_out, "%s%c", cp,
			    t->vars[i + 1] ? ' ' : '\n');
			if (!t->vars[i + 1])
				shf_flush(shl_out);
		}
		typeset(cp, type_flags, 0, 0, 0);
		if (bourne_function_call && !(type_flags & EXPORT))
			typeset(cp, LOCAL|LOCAL_COPY|EXPORT, 0, 0, 0);
	}

	if ((cp = *ap) == NULL) {
		rv = subst_exstat;
		goto Leave;
	} else if (!tp) {
		if (Flag(FRESTRICTED) && vstrchr(cp, '/')) {
			warningf(true, "%s: %s", cp, "restricted");
			rv = 1;
			goto Leave;
		}
		tp = findcom(cp, fcflags);
	}

	switch (tp->type) {

	/* shell built-in */
	case CSHELL:
		rv = call_builtin(tp, (const char **)ap, null);
		if (!keepasn_ok && tp->val.f == c_shift) {
			l_expand->argc = l_assign->argc;
			l_expand->argv = l_assign->argv;
		}
		break;

	/* function call */
	case CFUNC: {
		volatile unsigned char old_xflag;
		volatile uint32_t old_inuse;
		const char * volatile old_kshname;

		if (!(tp->flag & ISSET)) {
			struct tbl *ftp;

			if (!tp->u.fpath) {
				rv = (tp->u2.errnov == ENOENT) ? 127 : 126;
				warningf(true, "%s: %s %s: %s", cp,
				    "can't find", "function definition file",
				    cstrerror(tp->u2.errnov));
				break;
			}
			if (include(tp->u.fpath, 0, NULL, false) < 0) {
				rv = errno;
				warningf(true, "%s: %s %s %s: %s", cp,
				    "can't open", "function definition file",
				    tp->u.fpath, cstrerror(rv));
				rv = 127;
				break;
			}
			if (!(ftp = findfunc(cp, hash(cp), false)) ||
			    !(ftp->flag & ISSET)) {
				warningf(true, "%s: %s %s", cp,
				    "function not defined by", tp->u.fpath);
				rv = 127;
				break;
			}
			tp = ftp;
		}

		/*
		 * ksh functions set $0 to function name, POSIX
		 * functions leave $0 unchanged.
		 */
		old_kshname = kshname;
		if (tp->flag & FKSH)
			kshname = ap[0];
		else
			ap[0] = kshname;
		e->loc->argv = ap;
		for (i = 0; *ap++ != NULL; i++)
			;
		e->loc->argc = i - 1;
		/*
		 * ksh-style functions handle getopts sanely,
		 * Bourne/POSIX functions are insane...
		 */
		if (tp->flag & FKSH) {
			e->loc->flags |= BF_DOGETOPTS;
			e->loc->getopts_state = user_opt;
			getopts_reset(1);
		}

		old_xflag = Flag(FXTRACE);
		Flag(FXTRACE) |= tp->flag & TRACE ? 1 : 0;

		old_inuse = tp->flag & FINUSE;
		tp->flag |= FINUSE;

		e->type = E_FUNC;
		if (!(i = kshsetjmp(e->jbuf))) {
			execute(tp->val.t, flags & XERROK, NULL);
			i = LRETURN;
		}
		kshname = old_kshname;
		Flag(FXTRACE) = old_xflag;
		tp->flag = (tp->flag & ~FINUSE) | old_inuse;
		/*
		 * Were we deleted while executing? If so, free the
		 * execution tree. TODO: Unfortunately, the table entry
		 * is never re-used until the lookup table is expanded.
		 */
		if ((tp->flag & (FDELETE|FINUSE)) == FDELETE) {
			if (tp->flag & ALLOC) {
				tp->flag &= ~ALLOC;
				tfree(tp->val.t, tp->areap);
			}
			tp->flag = 0;
		}
		switch (i) {
		case LRETURN:
		case LERROR:
			rv = exstat & 0xFF;
			break;
		case LINTR:
		case LEXIT:
		case LLEAVE:
		case LSHELL:
			quitenv(NULL);
			unwind(i);
			/* NOTREACHED */
		default:
			quitenv(NULL);
			internal_errorf("%s %d", "CFUNC", i);
		}
		break;
	}

	/* executable command */
	case CEXEC:
	/* tracked alias */
	case CTALIAS:
		if (!(tp->flag&ISSET)) {
			if (tp->u2.errnov == ENOENT) {
				rv = 127;
				warningf(true, "%s: %s", cp, "not found");
			} else {
				rv = 126;
				warningf(true, "%s: %s: %s", cp, "can't execute",
				    cstrerror(tp->u2.errnov));
			}
			break;
		}

		/* set $_ to programme's full path */
		/* setstr() can't fail here */
		setstr(typeset("_", LOCAL|EXPORT, 0, INTEGER, 0),
		    tp->val.s, KSH_RETURN_ERROR);

		if (flags&XEXEC) {
			j_exit();
			if (!(flags&XBGND)
#ifndef MKSH_UNEMPLOYED
			    || Flag(FMONITOR)
#endif
			    ) {
				setexecsig(&sigtraps[SIGINT], SS_RESTORE_ORIG);
				setexecsig(&sigtraps[SIGQUIT], SS_RESTORE_ORIG);
			}
		}

		/* to fork we set up a TEXEC node and call execute */
		texec.type = TEXEC;
		/* for tprint */
		texec.left = t;
		texec.str = tp->val.s;
		texec.args = ap;
		rv = exchild(&texec, flags, xerrok, -1);
		break;
	}
 Leave:
	if (flags & XEXEC) {
		exstat = rv & 0xFF;
		unwind(LLEAVE);
	}
	return (rv);
}
Exemplo n.º 8
0
/*
 * execute command tree
 */
int
execute(struct op * volatile t,
    /* if XEXEC don't fork */
    volatile int flags,
    volatile int * volatile xerrok)
{
	int i;
	volatile int rv = 0, dummy = 0;
	int pv[2];
	const char ** volatile ap = NULL;
	char ** volatile up;
	const char *s, *ccp;
	struct ioword **iowp;
	struct tbl *tp = NULL;
	char *cp;

	if (t == NULL)
		return (0);

	/* Caller doesn't care if XERROK should propagate. */
	if (xerrok == NULL)
		xerrok = &dummy;

	if ((flags&XFORK) && !(flags&XEXEC) && t->type != TPIPE)
		/* run in sub-process */
		return (exchild(t, flags & ~XTIME, xerrok, -1));

	newenv(E_EXEC);
	if (trap)
		runtraps(0);

	/* we want to run an executable, do some variance checks */
	if (t->type == TCOM) {
		/* check if this is 'var=<<EOF' */
		if (
		    /* we have zero arguments, i.e. no programme to run */
		    t->args[0] == NULL &&
		    /* we have exactly one variable assignment */
		    t->vars[0] != NULL && t->vars[1] == NULL &&
		    /* we have exactly one I/O redirection */
		    t->ioact != NULL && t->ioact[0] != NULL &&
		    t->ioact[1] == NULL &&
		    /* of type "here document" (or "here string") */
		    (t->ioact[0]->flag & IOTYPE) == IOHERE &&
		    /* the variable assignment begins with a valid varname */
		    (ccp = skip_wdvarname(t->vars[0], true)) != t->vars[0] &&
		    /* and has no right-hand side (i.e. "varname=") */
		    ccp[0] == CHAR && ccp[1] == '=' && ccp[2] == EOS &&
		    /* plus we can have a here document content */
		    herein(t->ioact[0], &cp) == 0 && cp && *cp) {
			char *sp = cp, *dp;
			size_t n = ccp - t->vars[0] + 2, z;

			/* drop redirection (will be garbage collected) */
			t->ioact = NULL;

			/* set variable to its expanded value */
			z = strlen(cp) + 1;
			if (notoktomul(z, 2) || notoktoadd(z * 2, n))
				internal_errorf(Toomem, (unsigned long)-1);
			dp = alloc(z * 2 + n, ATEMP);
			memcpy(dp, t->vars[0], n);
			t->vars[0] = dp;
			dp += n;
			while (*sp) {
				*dp++ = QCHAR;
				*dp++ = *sp++;
			}
			*dp = EOS;
			/* free the expanded value */
			afree(cp, APERM);
		}

		/*
		 * Clear subst_exstat before argument expansion. Used by
		 * null commands (see comexec() and c_eval()) and by c_set().
		 */
		subst_exstat = 0;

		/* for $LINENO */
		current_lineno = t->lineno;

		/*
		 * POSIX says expand command words first, then redirections,
		 * and assignments last..
		 */
		up = eval(t->args, t->u.evalflags | DOBLANK | DOGLOB | DOTILDE);
		if (flags & XTIME)
			/* Allow option parsing (bizarre, but POSIX) */
			timex_hook(t, &up);
		ap = (const char **)up;
		if (Flag(FXTRACE) && ap[0]) {
			shf_puts(substitute(str_val(global("PS4")), 0),
			    shl_out);
			for (i = 0; ap[i]; i++)
				shf_fprintf(shl_out, "%s%c", ap[i],
				    ap[i + 1] ? ' ' : '\n');
			shf_flush(shl_out);
		}
		if (ap[0])
			tp = findcom(ap[0], FC_BI|FC_FUNC);
	}
	flags &= ~XTIME;

	if (t->ioact != NULL || t->type == TPIPE || t->type == TCOPROC) {
		e->savefd = alloc2(NUFILE, sizeof(short), ATEMP);
		/* initialise to not redirected */
		memset(e->savefd, 0, NUFILE * sizeof(short));
	}

	/* mark for replacement later (unless TPIPE) */
	vp_pipest->flag |= INT_L;

	/* do redirection, to be restored in quitenv() */
	if (t->ioact != NULL)
		for (iowp = t->ioact; *iowp != NULL; iowp++) {
			if (iosetup(*iowp, tp) < 0) {
				exstat = rv = 1;
				/*
				 * Redirection failures for special commands
				 * cause (non-interactive) shell to exit.
				 */
				if (tp && tp->type == CSHELL &&
				    (tp->flag & SPEC_BI))
					errorfz();
				/* Deal with FERREXIT, quitenv(), etc. */
				goto Break;
			}
		}

	switch (t->type) {
	case TCOM:
		rv = comexec(t, tp, (const char **)ap, flags, xerrok);
		break;

	case TPAREN:
		rv = execute(t->left, flags | XFORK, xerrok);
		break;

	case TPIPE:
		flags |= XFORK;
		flags &= ~XEXEC;
		e->savefd[0] = savefd(0);
		e->savefd[1] = savefd(1);
		while (t->type == TPIPE) {
			openpipe(pv);
			/* stdout of curr */
			ksh_dup2(pv[1], 1, false);
			/**
			 * Let exchild() close pv[0] in child
			 * (if this isn't done, commands like
			 *	(: ; cat /etc/termcap) | sleep 1
			 * will hang forever).
			 */
			exchild(t->left, flags | XPIPEO | XCCLOSE,
			    NULL, pv[0]);
			/* stdin of next */
			ksh_dup2(pv[0], 0, false);
			closepipe(pv);
			flags |= XPIPEI;
			t = t->right;
		}
		/* stdout of last */
		restfd(1, e->savefd[1]);
		/* no need to re-restore this */
		e->savefd[1] = 0;
		/* Let exchild() close 0 in parent, after fork, before wait */
		i = exchild(t, flags | XPCLOSE | XPIPEST, xerrok, 0);
		if (!(flags&XBGND) && !(flags&XXCOM))
			rv = i;
		break;

	case TLIST:
		while (t->type == TLIST) {
			execute(t->left, flags & XERROK, NULL);
			t = t->right;
		}
		rv = execute(t, flags & XERROK, xerrok);
		break;

	case TCOPROC: {
#ifndef MKSH_NOPROSPECTOFWORK
		sigset_t omask;

		/*
		 * Block sigchild as we are using things changed in the
		 * signal handler
		 */
		sigprocmask(SIG_BLOCK, &sm_sigchld, &omask);
		e->type = E_ERRH;
		if ((i = kshsetjmp(e->jbuf))) {
			sigprocmask(SIG_SETMASK, &omask, NULL);
			quitenv(NULL);
			unwind(i);
			/* NOTREACHED */
		}
#endif
		/* Already have a (live) co-process? */
		if (coproc.job && coproc.write >= 0)
			errorf("coprocess already exists");

		/* Can we re-use the existing co-process pipe? */
		coproc_cleanup(true);

		/* do this before opening pipes, in case these fail */
		e->savefd[0] = savefd(0);
		e->savefd[1] = savefd(1);

		openpipe(pv);
		if (pv[0] != 0) {
			ksh_dup2(pv[0], 0, false);
			close(pv[0]);
		}
		coproc.write = pv[1];
		coproc.job = NULL;

		if (coproc.readw >= 0)
			ksh_dup2(coproc.readw, 1, false);
		else {
			openpipe(pv);
			coproc.read = pv[0];
			ksh_dup2(pv[1], 1, false);
			/* closed before first read */
			coproc.readw = pv[1];
			coproc.njobs = 0;
			/* create new coprocess id */
			++coproc.id;
		}
#ifndef MKSH_NOPROSPECTOFWORK
		sigprocmask(SIG_SETMASK, &omask, NULL);
		/* no more need for error handler */
		e->type = E_EXEC;
#endif

		/*
		 * exchild() closes coproc.* in child after fork,
		 * will also increment coproc.njobs when the
		 * job is actually created.
		 */
		flags &= ~XEXEC;
		exchild(t->left, flags | XBGND | XFORK | XCOPROC | XCCLOSE,
		    NULL, coproc.readw);
		break;
	}

	case TASYNC:
		/*
		 * XXX non-optimal, I think - "(foo &)", forks for (),
		 * forks again for async... parent should optimise
		 * this to "foo &"...
		 */
		rv = execute(t->left, (flags&~XEXEC)|XBGND|XFORK, xerrok);
		break;

	case TOR:
	case TAND:
		rv = execute(t->left, XERROK, xerrok);
		if ((rv == 0) == (t->type == TAND))
			rv = execute(t->right, XERROK, xerrok);
		flags |= XERROK;
		if (xerrok)
			*xerrok = 1;
		break;

	case TBANG:
		rv = !execute(t->right, XERROK, xerrok);
		flags |= XERROK;
		if (xerrok)
			*xerrok = 1;
		break;

	case TDBRACKET: {
		Test_env te;

		te.flags = TEF_DBRACKET;
		te.pos.wp = t->args;
		te.isa = dbteste_isa;
		te.getopnd = dbteste_getopnd;
		te.eval = test_eval;
		te.error = dbteste_error;

		rv = test_parse(&te);
		break;
	}

	case TFOR:
	case TSELECT: {
		volatile bool is_first = true;
		ap = (t->vars == NULL) ? e->loc->argv + 1 :
		    (const char **)eval((const char **)t->vars,
		    DOBLANK | DOGLOB | DOTILDE);
		e->type = E_LOOP;
		while ((i = kshsetjmp(e->jbuf))) {
			if ((e->flags&EF_BRKCONT_PASS) ||
			    (i != LBREAK && i != LCONTIN)) {
				quitenv(NULL);
				unwind(i);
			} else if (i == LBREAK) {
				rv = 0;
				goto Break;
			}
		}
		/* in case of a continue */
		rv = 0;
		if (t->type == TFOR) {
			while (*ap != NULL) {
				setstr(global(t->str), *ap++, KSH_UNWIND_ERROR);
				rv = execute(t->left, flags & XERROK, xerrok);
			}
		} else {
			/* TSELECT */
			for (;;) {
				if (!(ccp = do_selectargs(ap, is_first))) {
					rv = 1;
					break;
				}
				is_first = false;
				setstr(global(t->str), ccp, KSH_UNWIND_ERROR);
				execute(t->left, flags & XERROK, xerrok);
			}
		}
		break;
	}

	case TWHILE:
	case TUNTIL:
		e->type = E_LOOP;
		while ((i = kshsetjmp(e->jbuf))) {
			if ((e->flags&EF_BRKCONT_PASS) ||
			    (i != LBREAK && i != LCONTIN)) {
				quitenv(NULL);
				unwind(i);
			} else if (i == LBREAK) {
				rv = 0;
				goto Break;
			}
		}
		/* in case of a continue */
		rv = 0;
		while ((execute(t->left, XERROK, NULL) == 0) ==
		    (t->type == TWHILE))
			rv = execute(t->right, flags & XERROK, xerrok);
		break;

	case TIF:
	case TELIF:
		if (t->right == NULL)
			/* should be error */
			break;
		rv = execute(t->left, XERROK, NULL) == 0 ?
		    execute(t->right->left, flags & XERROK, xerrok) :
		    execute(t->right->right, flags & XERROK, xerrok);
		break;

	case TCASE:
		i = 0;
		ccp = evalstr(t->str, DOTILDE);
		for (t = t->left; t != NULL && t->type == TPAT; t = t->right) {
			for (ap = (const char **)t->vars; *ap; ap++) {
				if (i || ((s = evalstr(*ap, DOTILDE|DOPAT)) &&
				    gmatchx(ccp, s, false))) {
					rv = execute(t->left, flags & XERROK,
					    xerrok);
					i = 0;
					switch (t->u.charflag) {
					case '&':
						i = 1;
						/* FALLTHROUGH */
					case '|':
						goto TCASE_next;
					}
					goto TCASE_out;
				}
			}
			i = 0;
 TCASE_next:
			/* empty */;
		}
 TCASE_out:
		break;

	case TBRACE:
		rv = execute(t->left, flags & XERROK, xerrok);
		break;

	case TFUNCT:
		rv = define(t->str, t);
		break;

	case TTIME:
		/*
		 * Clear XEXEC so nested execute() call doesn't exit
		 * (allows "ls -l | time grep foo").
		 */
		rv = timex(t, flags & ~XEXEC, xerrok);
		break;

	case TEXEC:
		/* an eval'd TCOM */
		s = t->args[0];
		up = makenv();
		restoresigs();
		cleanup_proc_env();
		{
			union mksh_ccphack cargs;

			cargs.ro = t->args;
			execve(t->str, cargs.rw, up);
			rv = errno;
		}
		if (rv == ENOEXEC)
			scriptexec(t, (const char **)up);
		else
			errorf("%s: %s", s, cstrerror(rv));
	}
 Break:
	exstat = rv & 0xFF;
	if (vp_pipest->flag & INT_L) {
		unset(vp_pipest, 1);
		vp_pipest->flag = DEFINED | ISSET | INTEGER | RDONLY |
		    ARRAY | INT_U;
		vp_pipest->val.i = rv;
	}

	/* restores IO */
	quitenv(NULL);
	if ((flags&XEXEC))
		/* exit child */
		unwind(LEXIT);
	if (rv != 0 && !(flags & XERROK) &&
	    (xerrok == NULL || !*xerrok)) {
		if (Flag(FERREXIT) & 0x80) {
			/* inside eval */
			Flag(FERREXIT) = 0;
		} else {
			trapsig(ksh_SIGERR);
			if (Flag(FERREXIT))
				unwind(LERROR);
		}
	}
	return (rv);
}
Exemplo n.º 9
0
/*
 * run the commands from the input source, returning status.
 */
int
shell(Source * volatile s, volatile int level)
{
	struct op *t;
	volatile bool wastty = tobool(s->flags & SF_TTY);
	volatile uint8_t attempts = 13;
	volatile bool interactive = (level == 0) && Flag(FTALKING);
	volatile bool sfirst = true;
	Source *volatile old_source = source;
	int i;

	newenv(level == 2 ? E_EVAL : E_PARSE);
	if (interactive)
		really_exit = false;
	switch ((i = kshsetjmp(e->jbuf))) {
	case 0:
		break;
	case LBREAK:
	case LCONTIN:
		if (level != 2) {
			source = old_source;
			quitenv(NULL);
			internal_errorf(Tf_cant_s, Tshell,
			    i == LBREAK ? Tbreak : Tcontinue);
			/* NOTREACHED */
		}
		/* assert: interactive == false */
		/* FALLTHROUGH */
	case LINTR:
		/* we get here if SIGINT not caught or ignored */
	case LERROR:
	case LSHELL:
		if (interactive) {
			if (i == LINTR)
				shellf("\n");
			/*
			 * Reset any eof that was read as part of a
			 * multiline command.
			 */
			if (Flag(FIGNOREEOF) && s->type == SEOF && wastty)
				s->type = SSTDIN;
			/*
			 * Used by exit command to get back to
			 * top level shell. Kind of strange since
			 * interactive is set if we are reading from
			 * a tty, but to have stopped jobs, one only
			 * needs FMONITOR set (not FTALKING/SF_TTY)...
			 */
			/* toss any input we have so far */
			yyrecursive_pop(true);
			s->start = s->str = null;
			retrace_info = NULL;
			herep = heres;
			break;
		}
		/* FALLTHROUGH */
	case LEXIT:
	case LLEAVE:
	case LRETURN:
		source = old_source;
		quitenv(NULL);
		/* keep on going */
		unwind(i);
		/* NOTREACHED */
	default:
		source = old_source;
		quitenv(NULL);
		internal_errorf(Tunexpected_type, Tunwind, Tshell, i);
		/* NOTREACHED */
	}
	while (/* CONSTCOND */ 1) {
		if (trap)
			runtraps(0);

		if (s->next == NULL) {
			if (Flag(FVERBOSE))
				s->flags |= SF_ECHO;
			else
				s->flags &= ~SF_ECHO;
		}
		if (interactive) {
			j_notify();
			set_prompt(PS1, s);
		}
		t = compile(s, sfirst, true);
		if (interactive)
			histsave(&s->line, NULL, HIST_FLUSH, true);
		sfirst = false;
		if (!t)
			goto source_no_tree;
		if (t->type == TEOF) {
			if (wastty && Flag(FIGNOREEOF) && --attempts > 0) {
				shellf("Use 'exit' to leave mksh\n");
				s->type = SSTDIN;
			} else if (wastty && !really_exit &&
			    j_stopped_running()) {
				really_exit = true;
				s->type = SSTDIN;
			} else {
				/*
				 * this for POSIX which says EXIT traps
				 * shall be taken in the environment
				 * immediately after the last command
				 * executed.
				 */
				if (level == 0)
					unwind(LEXIT);
				break;
			}
		} else if ((s->flags & SF_MAYEXEC) && t->type == TCOM)
			t->u.evalflags |= DOTCOMEXEC;
		if (!Flag(FNOEXEC) || (s->flags & SF_TTY))
			exstat = execute(t, 0, NULL) & 0xFF;

		if (t->type != TEOF && interactive && really_exit)
			really_exit = false;

 source_no_tree:
		reclaim();
	}
	quitenv(NULL);
	source = old_source;
	return (exstat & 0xFF);
}
Exemplo n.º 10
0
int
include(const char *name, int argc, const char **argv, bool intr_ok)
{
	Source *volatile s = NULL;
	struct shf *shf;
	const char **volatile old_argv;
	volatile int old_argc;
	int i;

	shf = shf_open(name, O_RDONLY, 0, SHF_MAPHI | SHF_CLEXEC);
	if (shf == NULL)
		return (-1);

	if (argv) {
		old_argv = e->loc->argv;
		old_argc = e->loc->argc;
	} else {
		old_argv = NULL;
		old_argc = 0;
	}
	newenv(E_INCL);
	if ((i = kshsetjmp(e->jbuf))) {
		quitenv(s ? s->u.shf : NULL);
		if (old_argv) {
			e->loc->argv = old_argv;
			e->loc->argc = old_argc;
		}
		switch (i) {
		case LRETURN:
		case LERROR:
			/* see below */
			return (exstat & 0xFF);
		case LINTR:
			/*
			 * intr_ok is set if we are including .profile or $ENV.
			 * If user ^Cs out, we don't want to kill the shell...
			 */
			if (intr_ok && ((exstat & 0xFF) - 128) != SIGTERM)
				return (1);
			/* FALLTHROUGH */
		case LEXIT:
		case LLEAVE:
		case LSHELL:
			unwind(i);
			/* NOTREACHED */
		default:
			internal_errorf(Tunexpected_type, Tunwind, Tsource, i);
			/* NOTREACHED */
		}
	}
	if (argv) {
		e->loc->argv = argv;
		e->loc->argc = argc;
	}
	s = pushs(SFILE, ATEMP);
	s->u.shf = shf;
	strdupx(s->file, name, ATEMP);
	i = shell(s, 1);
	quitenv(s->u.shf);
	if (old_argv) {
		e->loc->argv = old_argv;
		e->loc->argc = old_argc;
	}
	/* & 0xff to ensure value not -1 */
	return (i & 0xFF);
}
Exemplo n.º 11
0
static int
comexec(struct op *t, struct tbl * volatile tp, const char **ap,
    volatile int flags, volatile int *xerrok)
{
	int i;
	volatile int rv = 0;
	const char *cp;
	const char **lastp;
	/* Must be static (XXX but why?) */
	static struct op texec;
	int type_flags;
	bool resetspec;
	int fcflags = FC_BI|FC_FUNC|FC_PATH;
	struct block *l_expand, *l_assign;
	int optc;
	const char *exec_argv0 = NULL;
	bool exec_clrenv = false;

	/* snag the last argument for $_ */
	if (Flag(FTALKING) && *(lastp = ap)) {
		/*
		 * XXX not the same as AT&T ksh, which only seems to set $_
		 * after a newline (but not in functions/dot scripts, but in
		 * interactive and script) - perhaps save last arg here and
		 * set it in shell()?.
		 */
		while (*++lastp)
			;
		/* setstr() can't fail here */
		setstr(typeset("_", LOCAL, 0, INTEGER, 0), *--lastp,
		    KSH_RETURN_ERROR);
	}

	/**
	 * Deal with the shell builtins builtin, exec and command since
	 * they can be followed by other commands. This must be done before
	 * we know if we should create a local block which must be done
	 * before we can do a path search (in case the assignments change
	 * PATH).
	 * Odd cases:
	 *	FOO=bar exec >/dev/null		FOO is kept but not exported
	 *	FOO=bar exec foobar		FOO is exported
	 *	FOO=bar command exec >/dev/null	FOO is neither kept nor exported
	 *	FOO=bar command			FOO is neither kept nor exported
	 *	PATH=... foobar			use new PATH in foobar search
	 */
	resetspec = false;
	while (tp && tp->type == CSHELL) {
		/* undo effects of command */
		fcflags = FC_BI|FC_FUNC|FC_PATH;
		if (tp->val.f == c_builtin) {
			if ((cp = *++ap) == NULL ||
			    (!strcmp(cp, "--") && (cp = *++ap) == NULL)) {
				tp = NULL;
				break;
			}
			if ((tp = findcom(cp, FC_BI)) == NULL)
				errorf("%s: %s: %s", Tbuiltin, cp, "not a builtin");
			if (tp->type == CSHELL && (tp->val.f == c_cat
#ifdef MKSH_PRINTF_BUILTIN
			    || tp->val.f == c_printf
#endif
			    ))
				break;
			continue;
		} else if (tp->val.f == c_exec) {
			if (ap[1] == NULL)
				break;
			ksh_getopt_reset(&builtin_opt, GF_ERROR);
			while ((optc = ksh_getopt(ap, &builtin_opt, "a:c")) != -1)
				switch (optc) {
				case 'a':
					exec_argv0 = builtin_opt.optarg;
					break;
				case 'c':
					exec_clrenv = true;
					/* ensure we can actually do this */
					resetspec = true;
					break;
				default:
					rv = 2;
					goto Leave;
				}
			ap += builtin_opt.optind;
			flags |= XEXEC;
		} else if (tp->val.f == c_command) {
			bool saw_p = false;

			/*
			 * Ugly dealing with options in two places (here
			 * and in c_command(), but such is life)
			 */
			ksh_getopt_reset(&builtin_opt, 0);
			while ((optc = ksh_getopt(ap, &builtin_opt, ":p")) == 'p')
				saw_p = true;
			if (optc != -1)
				/* command -vV or something */
				break;
			/* don't look for functions */
			fcflags = FC_BI|FC_PATH;
			if (saw_p) {
				if (Flag(FRESTRICTED)) {
					warningf(true, "%s: %s",
					    "command -p", "restricted");
					rv = 1;
					goto Leave;
				}
				fcflags |= FC_DEFPATH;
			}
			ap += builtin_opt.optind;
			/*
			 * POSIX says special builtins lose their status
			 * if accessed using command.
			 */
			resetspec = true;
			if (!ap[0]) {
				/* ensure command with no args exits with 0 */
				subst_exstat = 0;
				break;
			}
		} else if (tp->val.f == c_cat) {
			/* if we have any flags, do not use the builtin */
			if (ap[1] && ap[1][0] == '-' && ap[1][1] != '\0' &&
			    /* argument, begins with -, is not - or -- */
			    (ap[1][1] != '-' || ap[1][2] != '\0')) {
				struct tbl *ext_cat;

				ext_cat = findcom(Tcat, FC_PATH | FC_FUNC);
				if (ext_cat && (ext_cat->type != CTALIAS ||
				    (ext_cat->flag & ISSET)))
					tp = ext_cat;
			}
			break;
#ifdef MKSH_PRINTF_BUILTIN
		} else if (tp->val.f == c_printf) {
			struct tbl *ext_printf;

			ext_printf = findcom(Tprintf, FC_PATH | FC_FUNC);
			if (ext_printf && (ext_printf->type != CTALIAS ||
			    (ext_printf->flag & ISSET)))
				tp = ext_printf;
			break;
#endif
		} else if (tp->val.f == c_trap) {
			t->u.evalflags &= ~DOTCOMEXEC;
			break;
		} else
			break;
		tp = findcom(ap[0], fcflags & (FC_BI|FC_FUNC));
	}
	if (t->u.evalflags & DOTCOMEXEC)
		flags |= XEXEC;
	l_expand = e->loc;
	if (!resetspec && (!ap[0] || (tp && (tp->flag & KEEPASN))))
		type_flags = 0;
	else {
		/* create new variable/function block */
		newblock();
		/* ksh functions don't keep assignments, POSIX functions do. */
		if (!resetspec && tp && tp->type == CFUNC &&
		    !(tp->flag & FKSH))
			type_flags = EXPORT;
		else
			type_flags = LOCAL|LOCAL_COPY|EXPORT;
	}
	l_assign = e->loc;
	if (exec_clrenv)
		l_assign->flags |= BF_STOPENV;
	if (Flag(FEXPORT))
		type_flags |= EXPORT;
	if (Flag(FXTRACE))
		change_xtrace(2, false);
	for (i = 0; t->vars[i]; i++) {
		/* do NOT lookup in the new var/fn block just created */
		e->loc = l_expand;
		cp = evalstr(t->vars[i], DOASNTILDE | DOSCALAR);
		e->loc = l_assign;
		if (Flag(FXTRACE)) {
			const char *ccp;

			ccp = skip_varname(cp, true);
			if (*ccp == '+')
				++ccp;
			if (*ccp == '=')
				++ccp;
			shf_write(cp, ccp - cp, shl_xtrace);
			print_value_quoted(shl_xtrace, ccp);
			shf_putc(' ', shl_xtrace);
		}
		/* but assign in there as usual */
		typeset(cp, type_flags, 0, 0, 0);
	}

	if (Flag(FXTRACE)) {
		change_xtrace(2, false);
		if (ap[rv = 0]) {
 xtrace_ap_loop:
			print_value_quoted(shl_xtrace, ap[rv]);
			if (ap[++rv]) {
				shf_putc(' ', shl_xtrace);
				goto xtrace_ap_loop;
			}
		}
		change_xtrace(1, false);
	}

	if ((cp = *ap) == NULL) {
		rv = subst_exstat;
		goto Leave;
	} else if (!tp) {
		if (Flag(FRESTRICTED) && vstrchr(cp, '/')) {
			warningf(true, "%s: %s", cp, "restricted");
			rv = 1;
			goto Leave;
		}
		tp = findcom(cp, fcflags);
	}

	switch (tp->type) {

	/* shell built-in */
	case CSHELL:
 do_call_builtin:
		rv = call_builtin(tp, (const char **)ap, null, resetspec);
		if (resetspec && tp->val.f == c_shift) {
			l_expand->argc = l_assign->argc;
			l_expand->argv = l_assign->argv;
		}
		break;

	/* function call */
	case CFUNC: {
		volatile uint32_t old_inuse;
		const char * volatile old_kshname;
		volatile uint8_t old_flags[FNFLAGS];

		if (!(tp->flag & ISSET)) {
			struct tbl *ftp;

			if (!tp->u.fpath) {
				rv = (tp->u2.errnov == ENOENT) ? 127 : 126;
				warningf(true, "%s: %s %s: %s", cp,
				    "can't find", "function definition file",
				    cstrerror(tp->u2.errnov));
				break;
			}
			if (include(tp->u.fpath, 0, NULL, false) < 0) {
				if (!strcmp(cp, Tcat)) {
 no_cat_in_FPATH:
					tp = findcom(Tcat, FC_BI);
					goto do_call_builtin;
				}
#ifdef MKSH_PRINTF_BUILTIN
				if (!strcmp(cp, Tprintf)) {
 no_printf_in_FPATH:
					tp = findcom(Tprintf, FC_BI);
					goto do_call_builtin;
				}
#endif
				warningf(true, "%s: %s %s %s: %s", cp,
				    "can't open", "function definition file",
				    tp->u.fpath, cstrerror(errno));
				rv = 127;
				break;
			}
			if (!(ftp = findfunc(cp, hash(cp), false)) ||
			    !(ftp->flag & ISSET)) {
				if (!strcmp(cp, Tcat))
					goto no_cat_in_FPATH;
#ifdef MKSH_PRINTF_BUILTIN
				if (!strcmp(cp, Tprintf))
					goto no_printf_in_FPATH;
#endif
				warningf(true, "%s: %s %s", cp,
				    "function not defined by", tp->u.fpath);
				rv = 127;
				break;
			}
			tp = ftp;
		}

		/*
		 * ksh functions set $0 to function name, POSIX
		 * functions leave $0 unchanged.
		 */
		old_kshname = kshname;
		if (tp->flag & FKSH)
			kshname = ap[0];
		else
			ap[0] = kshname;
		e->loc->argv = ap;
		for (i = 0; *ap++ != NULL; i++)
			;
		e->loc->argc = i - 1;
		/*
		 * ksh-style functions handle getopts sanely,
		 * Bourne/POSIX functions are insane...
		 */
		if (tp->flag & FKSH) {
			e->loc->flags |= BF_DOGETOPTS;
			e->loc->getopts_state = user_opt;
			getopts_reset(1);
		}

		for (type_flags = 0; type_flags < FNFLAGS; ++type_flags)
			old_flags[type_flags] = shell_flags[type_flags];
		change_xtrace((Flag(FXTRACEREC) ? Flag(FXTRACE) : 0) |
		    ((tp->flag & TRACE) ? 1 : 0), false);
		old_inuse = tp->flag & FINUSE;
		tp->flag |= FINUSE;

		e->type = E_FUNC;
		if (!(i = kshsetjmp(e->jbuf))) {
			execute(tp->val.t, flags & XERROK, NULL);
			i = LRETURN;
		}

		kshname = old_kshname;
		change_xtrace(old_flags[(int)FXTRACE], false);
#ifndef MKSH_LEGACY_MODE
		if (tp->flag & FKSH) {
			/* Korn style functions restore Flags on return */
			old_flags[(int)FXTRACE] = Flag(FXTRACE);
			for (type_flags = 0; type_flags < FNFLAGS; ++type_flags)
				shell_flags[type_flags] = old_flags[type_flags];
		}
#endif
		tp->flag = (tp->flag & ~FINUSE) | old_inuse;

		/*
		 * Were we deleted while executing? If so, free the
		 * execution tree.
		 */
		if ((tp->flag & (FDELETE|FINUSE)) == FDELETE) {
			if (tp->flag & ALLOC) {
				tp->flag &= ~ALLOC;
				tfree(tp->val.t, tp->areap);
			}
			tp->flag = 0;
		}
		switch (i) {
		case LRETURN:
		case LERROR:
			rv = exstat & 0xFF;
			break;
		case LINTR:
		case LEXIT:
		case LLEAVE:
		case LSHELL:
			quitenv(NULL);
			unwind(i);
			/* NOTREACHED */
		default:
			quitenv(NULL);
			internal_errorf("%s %d", "CFUNC", i);
		}
		break;
	}

	/* executable command */
	case CEXEC:
	/* tracked alias */
	case CTALIAS:
		if (!(tp->flag&ISSET)) {
			if (tp->u2.errnov == ENOENT) {
				rv = 127;
				warningf(true, "%s: %s", cp, "not found");
			} else {
				rv = 126;
				warningf(true, "%s: %s: %s", cp, "can't execute",
				    cstrerror(tp->u2.errnov));
			}
			break;
		}

		/* set $_ to program's full path */
		/* setstr() can't fail here */
		setstr(typeset("_", LOCAL | EXPORT, 0, INTEGER, 0),
		    tp->val.s, KSH_RETURN_ERROR);

		/* to fork, we set up a TEXEC node and call execute */
		texec.type = TEXEC;
		/* for vistree/dumptree */
		texec.left = t;
		texec.str = tp->val.s;
		texec.args = ap;

		/* in this case we do not fork, of course */
		if (flags & XEXEC) {
			if (exec_argv0)
				texec.args[0] = exec_argv0;
			j_exit();
			if (!(flags & XBGND)
#ifndef MKSH_UNEMPLOYED
			    || Flag(FMONITOR)
#endif
			    ) {
				setexecsig(&sigtraps[SIGINT], SS_RESTORE_ORIG);
				setexecsig(&sigtraps[SIGQUIT], SS_RESTORE_ORIG);
			}
		}

		rv = exchild(&texec, flags, xerrok, -1);
		break;
	}
 Leave:
	if (flags & XEXEC) {
		exstat = rv & 0xFF;
		unwind(LLEAVE);
	}
	return (rv);
}