예제 #1
0
파일: eval.c 프로젝트: 7shi/minix-tools
STATIC void
evalsubshell(union node *n, int flags)
{
	struct job *jp;
	int backgnd = (n->type == NBACKGND);

	expredir(n->nredir.redirect);
	jp = makejob(n, 1);
	if (forkshell(jp, n, backgnd) == 0) {
		if (backgnd)
			flags &=~ EV_TESTED;
		redirect(n->nredir.redirect, 0);
		evaltree(n->nredir.n, flags | EV_EXIT);	/* never returns */
	}
	if (! backgnd) {
		INTOFF;
		exitstatus = waitforjob(jp, (int *)NULL);
		INTON;
	}
}
예제 #2
0
static void
evalsubshell(union node *n, int flags)
{
	struct job *jp;
	int backgnd = (n->type == NBACKGND);

	oexitstatus = exitstatus;
	expredir(n->nredir.redirect);
	if ((!backgnd && flags & EV_EXIT && !have_traps()) ||
			forkshell(jp = makejob(n, 1), n, backgnd) == 0) {
		if (backgnd)
			flags &=~ EV_TESTED;
		redirect(n->nredir.redirect, 0);
		evaltree(n->nredir.n, flags | EV_EXIT);	/* never returns */
	} else if (! backgnd) {
		INTOFF;
		exitstatus = waitforjob(jp, (int *)NULL);
		INTON;
	}
}
예제 #3
0
파일: eval.c 프로젝트: dezelin/kBuild
STATIC void
evalsubshell(shinstance *psh, union node *n, int flags)
{
	struct job *jp;
	int backgnd = (n->type == NBACKGND);

	expredir(psh, n->nredir.redirect);
	INTOFF;
	jp = makejob(psh, n, 1);
	if (forkshell(psh, jp, n, backgnd ? FORK_BG : FORK_FG) == 0) {
		INTON;
		if (backgnd)
			flags &=~ EV_TESTED;
		redirect(psh, n->nredir.redirect, 0);
		/* never returns */
		evaltree(psh, n->nredir.n, flags | EV_EXIT);
	}
	if (! backgnd)
		psh->exitstatus = waitforjob(psh, jp);
	INTON;
}
예제 #4
0
파일: eval.c 프로젝트: dpl0/soc2013
static void
evalredir(union node *n, int flags)
{
	struct jmploc jmploc;
	struct jmploc *savehandler;
	volatile int in_redirect = 1;

	oexitstatus = exitstatus;
	expredir(n->nredir.redirect);
	savehandler = handler;
	if (setjmp(jmploc.loc)) {
		int e;

		handler = savehandler;
		e = exception;
		popredir();
		if (e == EXERROR || e == EXEXEC) {
			if (in_redirect) {
				exitstatus = 2;
				return;
			}
		}
		longjmp(handler->loc, 1);
	} else {
		INTOFF;
		handler = &jmploc;
		redirect(n->nredir.redirect, REDIR_PUSH);
		in_redirect = 0;
		INTON;
		evaltree(n->nredir.n, flags);
	}
	INTOFF;
	handler = savehandler;
	popredir();
	INTON;
}
예제 #5
0
파일: eval.c 프로젝트: dpl0/soc2013
static void
evalcommand(union node *cmd, int flags, struct backcmd *backcmd)
{
	union node *argp;
	struct arglist arglist;
	struct arglist varlist;
	char **argv;
	int argc;
	char **envp;
	int varflag;
	struct strlist *sp;
	int mode;
	int pip[2];
	struct cmdentry cmdentry;
	struct job *jp;
	struct jmploc jmploc;
	struct jmploc *savehandler;
	char *savecmdname;
	struct shparam saveparam;
	struct localvar *savelocalvars;
	struct parsefile *savetopfile;
	volatile int e;
	char *lastarg;
	int realstatus;
	int do_clearcmdentry;
	const char *path = pathval();

	/* First expand the arguments. */
	TRACE(("evalcommand(%p, %d) called\n", (void *)cmd, flags));
	arglist.lastp = &arglist.list;
	varlist.lastp = &varlist.list;
	varflag = 1;
	jp = NULL;
	do_clearcmdentry = 0;
	oexitstatus = exitstatus;
	exitstatus = 0;
	for (argp = cmd->ncmd.args ; argp ; argp = argp->narg.next) {
		if (varflag && isassignment(argp->narg.text)) {
			expandarg(argp, varflag == 1 ? &varlist : &arglist,
			    EXP_VARTILDE);
			continue;
		} else if (varflag == 1)
			varflag = isdeclarationcmd(&argp->narg) ? 2 : 0;
		expandarg(argp, &arglist, EXP_FULL | EXP_TILDE);
	}
	*arglist.lastp = NULL;
	*varlist.lastp = NULL;
	expredir(cmd->ncmd.redirect);
	argc = 0;
	for (sp = arglist.list ; sp ; sp = sp->next)
		argc++;
	/* Add one slot at the beginning for tryexec(). */
	argv = stalloc(sizeof (char *) * (argc + 2));
	argv++;

	for (sp = arglist.list ; sp ; sp = sp->next) {
		TRACE(("evalcommand arg: %s\n", sp->text));
		*argv++ = sp->text;
	}
	*argv = NULL;
	lastarg = NULL;
	if (iflag && funcnest == 0 && argc > 0)
		lastarg = argv[-1];
	argv -= argc;

	/* Print the command if xflag is set. */
	if (xflag) {
		char sep = 0;
		const char *p, *ps4;
		ps4 = expandstr(ps4val());
		out2str(ps4 != NULL ? ps4 : ps4val());
		for (sp = varlist.list ; sp ; sp = sp->next) {
			if (sep != 0)
				out2c(' ');
			p = strchr(sp->text, '=');
			if (p != NULL) {
				p++;
				outbin(sp->text, p - sp->text, out2);
				out2qstr(p);
			} else
				out2qstr(sp->text);
			sep = ' ';
		}
		for (sp = arglist.list ; sp ; sp = sp->next) {
			if (sep != 0)
				out2c(' ');
			/* Disambiguate command looking like assignment. */
			if (sp == arglist.list &&
					strchr(sp->text, '=') != NULL &&
					strchr(sp->text, '\'') == NULL) {
				out2c('\'');
				out2str(sp->text);
				out2c('\'');
			} else
				out2qstr(sp->text);
			sep = ' ';
		}
		out2c('\n');
		flushout(&errout);
	}

	/* Now locate the command. */
	if (argc == 0) {
		/* Variable assignment(s) without command */
		cmdentry.cmdtype = CMDBUILTIN;
		cmdentry.u.index = BLTINCMD;
		cmdentry.special = 0;
	} else {
		static const char PATH[] = "PATH=";
		int cmd_flags = 0, bltinonly = 0;

		/*
		 * Modify the command lookup path, if a PATH= assignment
		 * is present
		 */
		for (sp = varlist.list ; sp ; sp = sp->next)
			if (strncmp(sp->text, PATH, sizeof(PATH) - 1) == 0) {
				path = sp->text + sizeof(PATH) - 1;
				/*
				 * On `PATH=... command`, we need to make
				 * sure that the command isn't using the
				 * non-updated hash table of the outer PATH
				 * setting and we need to make sure that
				 * the hash table isn't filled with items
				 * from the temporary setting.
				 *
				 * It would be better to forbit using and
				 * updating the table while this command
				 * runs, by the command finding mechanism
				 * is heavily integrated with hash handling,
				 * so we just delete the hash before and after
				 * the command runs. Partly deleting like
				 * changepatch() does doesn't seem worth the
				 * bookinging effort, since most such runs add
				 * directories in front of the new PATH.
				 */
				clearcmdentry();
				do_clearcmdentry = 1;
			}

		for (;;) {
			if (bltinonly) {
				cmdentry.u.index = find_builtin(*argv, &cmdentry.special);
				if (cmdentry.u.index < 0) {
					cmdentry.u.index = BLTINCMD;
					argv--;
					argc++;
					break;
				}
			} else
				find_command(argv[0], &cmdentry, cmd_flags, path);
			/* implement the bltin and command builtins here */
			if (cmdentry.cmdtype != CMDBUILTIN)
				break;
			if (cmdentry.u.index == BLTINCMD) {
				if (argc == 1)
					break;
				argv++;
				argc--;
				bltinonly = 1;
			} else if (cmdentry.u.index == COMMANDCMD) {
				if (argc == 1)
					break;
				if (!strcmp(argv[1], "-p")) {
					if (argc == 2)
						break;
					if (argv[2][0] == '-') {
						if (strcmp(argv[2], "--"))
							break;
						if (argc == 3)
							break;
						argv += 3;
						argc -= 3;
					} else {
						argv += 2;
						argc -= 2;
					}
					path = _PATH_STDPATH;
					clearcmdentry();
					do_clearcmdentry = 1;
				} else if (!strcmp(argv[1], "--")) {
					if (argc == 2)
						break;
					argv += 2;
					argc -= 2;
				} else if (argv[1][0] == '-')
					break;
				else {
					argv++;
					argc--;
				}
				cmd_flags |= DO_NOFUNC;
				bltinonly = 0;
			} else
				break;
		}
		/*
		 * Special builtins lose their special properties when
		 * called via 'command'.
		 */
		if (cmd_flags & DO_NOFUNC)
			cmdentry.special = 0;
	}

	/* Fork off a child process if necessary. */
	if (((cmdentry.cmdtype == CMDNORMAL || cmdentry.cmdtype == CMDUNKNOWN)
	    && ((flags & EV_EXIT) == 0 || have_traps()))
	 || ((flags & EV_BACKCMD) != 0
	    && (cmdentry.cmdtype != CMDBUILTIN ||
		 !safe_builtin(cmdentry.u.index, argc, argv)))) {
		jp = makejob(cmd, 1);
		mode = FORK_FG;
		if (flags & EV_BACKCMD) {
			mode = FORK_NOJOB;
			if (pipe(pip) < 0)
				error("Pipe call failed: %s", strerror(errno));
		}
		if (cmdentry.cmdtype == CMDNORMAL &&
		    cmd->ncmd.redirect == NULL &&
		    varlist.list == NULL &&
		    (mode == FORK_FG || mode == FORK_NOJOB) &&
		    !disvforkset() && !iflag && !mflag) {
			vforkexecshell(jp, argv, environment(), path,
			    cmdentry.u.index, flags & EV_BACKCMD ? pip : NULL);
			goto parent;
		}
		if (forkshell(jp, cmd, mode) != 0)
			goto parent;	/* at end of routine */
		if (flags & EV_BACKCMD) {
			FORCEINTON;
			close(pip[0]);
			if (pip[1] != 1) {
				dup2(pip[1], 1);
				close(pip[1]);
			}
			flags &= ~EV_BACKCMD;
		}
		flags |= EV_EXIT;
	}

	/* This is the child process if a fork occurred. */
	/* Execute the command. */
	if (cmdentry.cmdtype == CMDFUNCTION) {
#ifdef DEBUG
		trputs("Shell function:  ");  trargs(argv);
#endif
		saveparam = shellparam;
		shellparam.malloc = 0;
		shellparam.reset = 1;
		shellparam.nparam = argc - 1;
		shellparam.p = argv + 1;
		shellparam.optnext = NULL;
		INTOFF;
		savelocalvars = localvars;
		localvars = NULL;
		reffunc(cmdentry.u.func);
		savehandler = handler;
		if (setjmp(jmploc.loc)) {
			freeparam(&shellparam);
			shellparam = saveparam;
			popredir();
			unreffunc(cmdentry.u.func);
			poplocalvars();
			localvars = savelocalvars;
			funcnest--;
			handler = savehandler;
			longjmp(handler->loc, 1);
		}
		handler = &jmploc;
		funcnest++;
		redirect(cmd->ncmd.redirect, REDIR_PUSH);
		INTON;
		for (sp = varlist.list ; sp ; sp = sp->next)
			mklocal(sp->text);
		exitstatus = oexitstatus;
		evaltree(getfuncnode(cmdentry.u.func),
		    flags & (EV_TESTED | EV_EXIT));
		INTOFF;
		unreffunc(cmdentry.u.func);
		poplocalvars();
		localvars = savelocalvars;
		freeparam(&shellparam);
		shellparam = saveparam;
		handler = savehandler;
		funcnest--;
		popredir();
		INTON;
		if (evalskip == SKIPFUNC) {
			evalskip = 0;
			skipcount = 0;
		}
		if (jp)
			exitshell(exitstatus);
	} else if (cmdentry.cmdtype == CMDBUILTIN) {
#ifdef DEBUG
		trputs("builtin command:  ");  trargs(argv);
#endif
		mode = (cmdentry.u.index == EXECCMD)? 0 : REDIR_PUSH;
		if (flags == EV_BACKCMD) {
			memout.nleft = 0;
			memout.nextc = memout.buf;
			memout.bufsize = 64;
			mode |= REDIR_BACKQ;
		}
		savecmdname = commandname;
		savetopfile = getcurrentfile();
		cmdenviron = varlist.list;
		e = -1;
		savehandler = handler;
		if (setjmp(jmploc.loc)) {
			e = exception;
			if (e == EXINT)
				exitstatus = SIGINT+128;
			else if (e != EXEXIT)
				exitstatus = 2;
			goto cmddone;
		}
		handler = &jmploc;
		redirect(cmd->ncmd.redirect, mode);
		outclearerror(out1);
		/*
		 * If there is no command word, redirection errors should
		 * not be fatal but assignment errors should.
		 */
		if (argc == 0)
			cmdentry.special = 1;
		listsetvar(cmdenviron, cmdentry.special ? 0 : VNOSET);
		if (argc > 0)
			bltinsetlocale();
		commandname = argv[0];
		argptr = argv + 1;
		nextopt_optptr = NULL;		/* initialize nextopt */
		builtin_flags = flags;
		exitstatus = (*builtinfunc[cmdentry.u.index])(argc, argv);
		flushall();
		if (outiserror(out1)) {
			warning("write error on stdout");
			if (exitstatus == 0 || exitstatus == 1)
				exitstatus = 2;
		}
cmddone:
		if (argc > 0)
			bltinunsetlocale();
		cmdenviron = NULL;
		out1 = &output;
		out2 = &errout;
		freestdout();
		handler = savehandler;
		commandname = savecmdname;
		if (jp)
			exitshell(exitstatus);
		if (flags == EV_BACKCMD) {
			backcmd->buf = memout.buf;
			backcmd->nleft = memout.nextc - memout.buf;
			memout.buf = NULL;
		}
		if (cmdentry.u.index != EXECCMD)
			popredir();
		if (e != -1) {
			if ((e != EXERROR && e != EXEXEC)
			    || cmdentry.special)
				exraise(e);
			popfilesupto(savetopfile);
			if (flags != EV_BACKCMD)
				FORCEINTON;
		}
	} else {
#ifdef DEBUG
		trputs("normal command:  ");  trargs(argv);
#endif
		redirect(cmd->ncmd.redirect, 0);
		for (sp = varlist.list ; sp ; sp = sp->next)
			setvareq(sp->text, VEXPORT|VSTACK);
		envp = environment();
		shellexec(argv, envp, path, cmdentry.u.index);
		/*NOTREACHED*/
	}
	goto out;

parent:	/* parent process gets here (if we forked) */
	if (mode == FORK_FG) {	/* argument to fork */
		INTOFF;
		exitstatus = waitforjob(jp, &realstatus);
		INTON;
		if (iflag && loopnest > 0 && WIFSIGNALED(realstatus)) {
			evalskip = SKIPBREAK;
			skipcount = loopnest;
		}
	} else if (mode == FORK_NOJOB) {
		backcmd->fd = pip[0];
		close(pip[1]);
		backcmd->jp = jp;
	}

out:
	if (lastarg)
		setvar("_", lastarg, 0);
	if (do_clearcmdentry)
		clearcmdentry();
}
예제 #6
0
파일: eval.c 프로젝트: chenguo/dash
void
evaltree(union node *n, int flags)
{
	int checkexit = 0;
	void (*evalfn)(union node *, int);
	unsigned isor;
	int status;
	if (n == NULL) {
		//TRACE(("evaltree(NULL) called\n"));
		goto out;
	}
#ifndef SMALL
	displayhist = 1;	/* show history substitutions done with fc */
#endif
	TRACE(("pid %d, evaltree(%p: %d, %d, %p) called\n",
	    getpid(), n, n->type, flags));
	switch (n->type) {
	default:
#ifdef DEBUG
#ifndef USE_GLIBC_STDIO
		flushout(out1);
#endif
		break;
#endif
	case NNOT:
		evaltree(n->nnot.com, EV_TESTED);
		status = !exitstatus;
		goto setstatus;
	case NREDIR:
		expredir(n->nredir.redirect);
		status = redirectsafe(n->nredir.redirect, REDIR_PUSH);
		if (!status) {
			evaltree(n->nredir.n, flags & EV_TESTED);
			status = exitstatus;
		}
		popredir(0);
		goto setstatus;
	case NCMD:
#ifdef notyet
		if (eflag && !(flags & EV_TESTED))
			checkexit = ~0;
		evalcommand(n, flags, (struct backcmd *)NULL);
		break;
#else
		evalfn = evalcommand;
checkexit:
		if (eflag && !(flags & EV_TESTED))
			checkexit = ~0;
		goto calleval;
#endif
	case NFOR:
		evalfn = evalfor;
		goto calleval;
	case NWHILE:
	case NUNTIL:
		evalfn = evalloop;
		goto calleval;
	case NSUBSHELL:
	case NBACKGND:
		evalfn = evalsubshell;
		evalsubshell (n, flags);
	case NPIPE:
		evalfn = evalpipe;
#ifdef notyet
		if (eflag && !(flags & EV_TESTED))
			checkexit = ~0;
		goto calleval;
#else
		goto checkexit;
#endif
	case NCASE:
		evalfn = evalcase;
		goto calleval;
	case NAND:
	case NOR:
	case NSEMI:
#if NAND + 1 != NOR
#error NAND + 1 != NOR
#endif
#if NOR + 1 != NSEMI
#error NOR + 1 != NSEMI
#endif
		isor = n->type - NAND;
		evaltree(
			n->nbinary.ch1,
			(flags | ((isor >> 1) - 1)) & EV_TESTED
		);
		if (!exitstatus == isor)
			break;
		if (!evalskip) {
			n = n->nbinary.ch2;
evaln:
			evaltree(n, flags);
			break;
calleval:
			evalfn(n, flags);
			break;
		}
		break;
	case NIF:
		evaltree(n->nif.test, EV_TESTED);
		if (evalskip)
			break;
		if (exitstatus == 0) {
			n = n->nif.ifpart;
			goto evaln;
		} else if (n->nif.elsepart) {
			n = n->nif.elsepart;
			goto evaln;
		}
		goto success;
	case NDEFUN:
		defun(n->narg.text, n->narg.next);
success:
		status = 0;
setstatus:
		exitstatus = status;
		break;
	}
out:
	if ((checkexit & exitstatus) ||
	    (pendingsigs && dotrap()) ||
	    (flags & EV_EXIT))
		exraise(EXEXIT);
}
예제 #7
0
static void
evalcommand(union node *cmd, int flags, struct backcmd *backcmd)
{
	struct stackmark smark;
	union node *argp;
	struct arglist arglist;
	struct arglist varlist;
	char **argv;
	int argc;
	char **envp;
	int varflag;
	struct strlist *sp;
	int mode;
	int pip[2];
	struct cmdentry cmdentry;
	struct job *jp;
	struct jmploc jmploc;
	struct jmploc *savehandler;
	char *savecmdname;
	struct shparam saveparam;
	struct localvar *savelocalvars;
	volatile int e;
	char *lastarg;
	int realstatus;
	int do_clearcmdentry;

	/* First expand the arguments. */
	TRACE(("evalcommand(%p, %d) called\n", (void *)cmd, flags));
	setstackmark(&smark);
	arglist.lastp = &arglist.list;
	varlist.lastp = &varlist.list;
	varflag = 1;
	do_clearcmdentry = 0;
	oexitstatus = exitstatus;
	exitstatus = 0;
	for (argp = cmd->ncmd.args ; argp ; argp = argp->narg.next) {
		char *p = argp->narg.text;
		if (varflag && is_name(*p)) {
			do {
				p++;
			} while (is_in_name(*p));
			if (*p == '=') {
				expandarg(argp, &varlist, EXP_VARTILDE);
				continue;
			}
		}
		expandarg(argp, &arglist, EXP_FULL | EXP_TILDE);
		varflag = 0;
	}
	*arglist.lastp = NULL;
	*varlist.lastp = NULL;
	expredir(cmd->ncmd.redirect);
	argc = 0;
	for (sp = arglist.list ; sp ; sp = sp->next)
		argc++;
	argv = stalloc(sizeof (char *) * (argc + 1));

	for (sp = arglist.list ; sp ; sp = sp->next) {
		TRACE(("evalcommand arg: %s\n", sp->text));
		*argv++ = sp->text;
	}
	*argv = NULL;
	lastarg = NULL;
	if (iflag && funcnest == 0 && argc > 0)
		lastarg = argv[-1];
	argv -= argc;

	/* Print the command if xflag is set. */
	if (xflag) {
		char sep = 0;
		const char *p;
		out2str(ps4val());
		for (sp = varlist.list ; sp ; sp = sp->next) {
			if (sep != 0)
				outc(' ', &errout);
			p = sp->text;
			while (*p != '=' && *p != '\0')
				out2c(*p++);
			if (*p != '\0') {
				out2c(*p++);
				out2qstr(p);
			}
			sep = ' ';
		}
		for (sp = arglist.list ; sp ; sp = sp->next) {
			if (sep != 0)
				outc(' ', &errout);
			/* Disambiguate command looking like assignment. */
			if (sp == arglist.list &&
					strchr(sp->text, '=') != NULL &&
					strchr(sp->text, '\'') == NULL) {
				out2c('\'');
				out2str(sp->text);
				out2c('\'');
			} else
				out2qstr(sp->text);
			sep = ' ';
		}
		outc('\n', &errout);
		flushout(&errout);
	}

	/* Now locate the command. */
	if (argc == 0) {
		/* Variable assignment(s) without command */
		cmdentry.cmdtype = CMDBUILTIN;
		cmdentry.u.index = BLTINCMD;
		cmdentry.special = 1;
	} else {
		static const char PATH[] = "PATH=";
		char *path = pathval();

		/*
		 * Modify the command lookup path, if a PATH= assignment
		 * is present
		 */
		for (sp = varlist.list ; sp ; sp = sp->next)
			if (strncmp(sp->text, PATH, sizeof(PATH) - 1) == 0) {
				path = sp->text + sizeof(PATH) - 1;
				/*
				 * On `PATH=... command`, we need to make
				 * sure that the command isn't using the
				 * non-updated hash table of the outer PATH
				 * setting and we need to make sure that
				 * the hash table isn't filled with items
				 * from the temporary setting.
				 *
				 * It would be better to forbit using and
				 * updating the table while this command
				 * runs, by the command finding mechanism
				 * is heavily integrated with hash handling,
				 * so we just delete the hash before and after
				 * the command runs. Partly deleting like
				 * changepatch() does doesn't seem worth the
				 * bookinging effort, since most such runs add
				 * directories in front of the new PATH.
				 */
				clearcmdentry(0);
				do_clearcmdentry = 1;
			}

		find_command(argv[0], &cmdentry, 1, path);
		if (cmdentry.cmdtype == CMDUNKNOWN) {	/* command not found */
			exitstatus = 127;
			flushout(&errout);
			return;
		}
		/* implement the bltin builtin here */
		if (cmdentry.cmdtype == CMDBUILTIN && cmdentry.u.index == BLTINCMD) {
			for (;;) {
				argv++;
				if (--argc == 0)
					break;
				if ((cmdentry.u.index = find_builtin(*argv,
				    &cmdentry.special)) < 0) {
					outfmt(&errout, "%s: not found\n", *argv);
					exitstatus = 127;
					flushout(&errout);
					return;
				}
				if (cmdentry.u.index != BLTINCMD)
					break;
			}
		}
	}

	/* Fork off a child process if necessary. */
	if (cmd->ncmd.backgnd
	 || (cmdentry.cmdtype == CMDNORMAL
	    && ((flags & EV_EXIT) == 0 || have_traps()))
	 || ((flags & EV_BACKCMD) != 0
	    && (cmdentry.cmdtype != CMDBUILTIN
		 || cmdentry.u.index == CDCMD
		 || cmdentry.u.index == DOTCMD
		 || cmdentry.u.index == EVALCMD))
	 || (cmdentry.cmdtype == CMDBUILTIN &&
	    cmdentry.u.index == COMMANDCMD)) {
		jp = makejob(cmd, 1);
		mode = cmd->ncmd.backgnd;
		if (flags & EV_BACKCMD) {
			mode = FORK_NOJOB;
			if (pipe(pip) < 0)
				error("Pipe call failed: %s", strerror(errno));
		}
		if (forkshell(jp, cmd, mode) != 0)
			goto parent;	/* at end of routine */
		if (flags & EV_BACKCMD) {
			FORCEINTON;
			close(pip[0]);
			if (pip[1] != 1) {
				dup2(pip[1], 1);
				close(pip[1]);
			}
		}
		flags |= EV_EXIT;
	}

	/* This is the child process if a fork occurred. */
	/* Execute the command. */
	if (cmdentry.cmdtype == CMDFUNCTION) {
#ifdef DEBUG
		trputs("Shell function:  ");  trargs(argv);
#endif
		redirect(cmd->ncmd.redirect, REDIR_PUSH);
		saveparam = shellparam;
		shellparam.malloc = 0;
		shellparam.reset = 1;
		shellparam.nparam = argc - 1;
		shellparam.p = argv + 1;
		shellparam.optnext = NULL;
		INTOFF;
		savelocalvars = localvars;
		localvars = NULL;
		reffunc(cmdentry.u.func);
		INTON;
		savehandler = handler;
		if (setjmp(jmploc.loc)) {
			if (exception == EXSHELLPROC)
				freeparam(&saveparam);
			else {
				freeparam(&shellparam);
				shellparam = saveparam;
			}
			unreffunc(cmdentry.u.func);
			poplocalvars();
			localvars = savelocalvars;
			handler = savehandler;
			longjmp(handler->loc, 1);
		}
		handler = &jmploc;
		for (sp = varlist.list ; sp ; sp = sp->next)
			mklocal(sp->text);
		funcnest++;
		exitstatus = oexitstatus;
		if (flags & EV_TESTED)
			evaltree(getfuncnode(cmdentry.u.func), EV_TESTED);
		else
			evaltree(getfuncnode(cmdentry.u.func), 0);
		funcnest--;
		INTOFF;
		unreffunc(cmdentry.u.func);
		poplocalvars();
		localvars = savelocalvars;
		freeparam(&shellparam);
		shellparam = saveparam;
		handler = savehandler;
		popredir();
		INTON;
		if (evalskip == SKIPFUNC) {
			evalskip = 0;
			skipcount = 0;
		}
		if (flags & EV_EXIT)
			exitshell(exitstatus);
	} else if (cmdentry.cmdtype == CMDBUILTIN) {
#ifdef DEBUG
		trputs("builtin command:  ");  trargs(argv);
#endif
		mode = (cmdentry.u.index == EXECCMD)? 0 : REDIR_PUSH;
		if (flags == EV_BACKCMD) {
			memout.nleft = 0;
			memout.nextc = memout.buf;
			memout.bufsize = 64;
			mode |= REDIR_BACKQ;
		}
		savecmdname = commandname;
		cmdenviron = varlist.list;
		e = -1;
		savehandler = handler;
		if (setjmp(jmploc.loc)) {
			e = exception;
			exitstatus = (e == EXINT)? SIGINT+128 : 2;
			goto cmddone;
		}
		handler = &jmploc;
		redirect(cmd->ncmd.redirect, mode);
		if (cmdentry.special)
			listsetvar(cmdenviron);
		commandname = argv[0];
		argptr = argv + 1;
		nextopt_optptr = NULL;		/* initialize nextopt */
		builtin_flags = flags;
		exitstatus = (*builtinfunc[cmdentry.u.index])(argc, argv);
		flushall();
cmddone:
		cmdenviron = NULL;
		out1 = &output;
		out2 = &errout;
		freestdout();
		if (e != EXSHELLPROC) {
			commandname = savecmdname;
			if (flags & EV_EXIT) {
				exitshell(exitstatus);
			}
		}
		handler = savehandler;
		if (e != -1) {
			if ((e != EXERROR && e != EXEXEC)
			    || cmdentry.special)
				exraise(e);
			FORCEINTON;
		}
		if (cmdentry.u.index != EXECCMD)
			popredir();
		if (flags == EV_BACKCMD) {
			backcmd->buf = memout.buf;
			backcmd->nleft = memout.nextc - memout.buf;
			memout.buf = NULL;
		}
	} else {
#ifdef DEBUG
		trputs("normal command:  ");  trargs(argv);
#endif
		clearredir();
		redirect(cmd->ncmd.redirect, 0);
		for (sp = varlist.list ; sp ; sp = sp->next)
			setvareq(sp->text, VEXPORT|VSTACK);
		envp = environment();
		shellexec(argv, envp, pathval(), cmdentry.u.index);
		/*NOTREACHED*/
	}
	goto out;

parent:	/* parent process gets here (if we forked) */
	if (mode == FORK_FG) {	/* argument to fork */
		INTOFF;
		exitstatus = waitforjob(jp, &realstatus);
		INTON;
		if (iflag && loopnest > 0 && WIFSIGNALED(realstatus)) {
			evalskip = SKIPBREAK;
			skipcount = loopnest;
		}
	} else if (mode == FORK_NOJOB) {
		backcmd->fd = pip[0];
		close(pip[1]);
		backcmd->jp = jp;
	}

out:
	if (lastarg)
		setvar("_", lastarg, 0);
	if (do_clearcmdentry)
		clearcmdentry(0);
	popstackmark(&smark);
}
예제 #8
0
void
evaltree(union node *n, int flags)
{
	int do_etest;

	do_etest = 0;
	if (n == NULL) {
		TRACE(("evaltree(NULL) called\n"));
		exitstatus = 0;
		goto out;
	}
#ifndef NO_HISTORY
	displayhist = 1;	/* show history substitutions done with fc */
#endif
	TRACE(("evaltree(%p: %d) called\n", (void *)n, n->type));
	switch (n->type) {
	case NSEMI:
		evaltree(n->nbinary.ch1, flags & ~EV_EXIT);
		if (evalskip)
			goto out;
		evaltree(n->nbinary.ch2, flags);
		break;
	case NAND:
		evaltree(n->nbinary.ch1, EV_TESTED);
		if (evalskip || exitstatus != 0) {
			goto out;
		}
		evaltree(n->nbinary.ch2, flags);
		break;
	case NOR:
		evaltree(n->nbinary.ch1, EV_TESTED);
		if (evalskip || exitstatus == 0)
			goto out;
		evaltree(n->nbinary.ch2, flags);
		break;
	case NREDIR:
		oexitstatus = exitstatus;
		expredir(n->nredir.redirect);
		redirect(n->nredir.redirect, REDIR_PUSH);
		evaltree(n->nredir.n, flags);
		popredir();
		break;
	case NSUBSHELL:
		evalsubshell(n, flags);
		do_etest = !(flags & EV_TESTED);
		break;
	case NBACKGND:
		evalsubshell(n, flags);
		break;
	case NIF: {
		evaltree(n->nif.test, EV_TESTED);
		if (evalskip)
			goto out;
		if (exitstatus == 0)
			evaltree(n->nif.ifpart, flags);
		else if (n->nif.elsepart)
			evaltree(n->nif.elsepart, flags);
		else
			exitstatus = 0;
		break;
	}
	case NWHILE:
	case NUNTIL:
		evalloop(n, flags & ~EV_EXIT);
		break;
	case NFOR:
		evalfor(n, flags & ~EV_EXIT);
		break;
	case NCASE:
		evalcase(n, flags);
		break;
	case NDEFUN:
		defun(n->narg.text, n->narg.next);
		exitstatus = 0;
		break;
	case NNOT:
		evaltree(n->nnot.com, EV_TESTED);
		exitstatus = !exitstatus;
		break;

	case NPIPE:
		evalpipe(n);
		do_etest = !(flags & EV_TESTED);
		break;
	case NCMD:
		evalcommand(n, flags, (struct backcmd *)NULL);
		do_etest = !(flags & EV_TESTED);
		break;
	default:
		out1fmt("Node type = %d\n", n->type);
		flushout(&output);
		break;
	}
out:
	if (pendingsigs)
		dotrap();
	if ((flags & EV_EXIT) || (eflag && exitstatus != 0 && do_etest))
		exitshell(exitstatus);
}
예제 #9
0
파일: eval.c 프로젝트: dezelin/kBuild
STATIC void
evalcommand(shinstance *psh, union node *cmd, int flags, struct backcmd *backcmd)
{
	struct stackmark smark;
	union node *argp;
	struct arglist arglist;
	struct arglist varlist;
	char **argv;
	int argc;
	char **envp;
	int varflag;
	struct strlist *sp;
	int mode;
	int pip[2];
	struct cmdentry cmdentry;
	struct job *jp;
	struct jmploc jmploc;
	struct jmploc *volatile savehandler;
	char *volatile savecmdname;
	volatile struct shparam saveparam;
	struct localvar *volatile savelocalvars;
	volatile int e;
	char *lastarg;
	const char *path = pathval(psh);
	volatile int temp_path;
#if __GNUC__
	/* Avoid longjmp clobbering */
	(void) &argv;
	(void) &argc;
	(void) &lastarg;
	(void) &flags;
#endif

	psh->vforked = 0;
	/* First expand the arguments. */
	TRACE((psh, "evalcommand(0x%lx, %d) called\n", (long)cmd, flags));
	setstackmark(psh, &smark);
	psh->back_exitstatus = 0;

	arglist.lastp = &arglist.list;
	varflag = 1;
	/* Expand arguments, ignoring the initial 'name=value' ones */
	for (argp = cmd->ncmd.args ; argp ; argp = argp->narg.next) {
		char *p = argp->narg.text;
		if (varflag && is_name(*p)) {
			do {
				p++;
			} while (is_in_name(*p));
			if (*p == '=')
				continue;
		}
		expandarg(psh, argp, &arglist, EXP_FULL | EXP_TILDE);
		varflag = 0;
	}
	*arglist.lastp = NULL;

	expredir(psh, cmd->ncmd.redirect);

	/* Now do the initial 'name=value' ones we skipped above */
	varlist.lastp = &varlist.list;
	for (argp = cmd->ncmd.args ; argp ; argp = argp->narg.next) {
		char *p = argp->narg.text;
		if (!is_name(*p))
			break;
		do
			p++;
		while (is_in_name(*p));
		if (*p != '=')
			break;
		expandarg(psh, argp, &varlist, EXP_VARTILDE);
	}
	*varlist.lastp = NULL;

	argc = 0;
	for (sp = arglist.list ; sp ; sp = sp->next)
		argc++;
	argv = stalloc(psh, sizeof (char *) * (argc + 1));

	for (sp = arglist.list ; sp ; sp = sp->next) {
		TRACE((psh, "evalcommand arg: %s\n", sp->text));
		*argv++ = sp->text;
	}
	*argv = NULL;
	lastarg = NULL;
	if (iflag(psh) && psh->funcnest == 0 && argc > 0)
		lastarg = argv[-1];
	argv -= argc;

	/* Print the command if xflag is set. */
	if (xflag(psh)) {
		char sep = 0;
		out2str(psh, ps4val(psh));
		for (sp = varlist.list ; sp ; sp = sp->next) {
			if (sep != 0)
				outc(sep, &psh->errout);
			out2str(psh, sp->text);
			sep = ' ';
		}
		for (sp = arglist.list ; sp ; sp = sp->next) {
			if (sep != 0)
				outc(sep, &psh->errout);
			out2str(psh, sp->text);
			sep = ' ';
		}
		outc('\n', &psh->errout);
		flushout(&psh->errout);
	}

	/* Now locate the command. */
	if (argc == 0) {
		cmdentry.cmdtype = CMDSPLBLTIN;
		cmdentry.u.bltin = bltincmd;
	} else {
		static const char PATH[] = "PATH=";
		int cmd_flags = DO_ERR;

		/*
		 * Modify the command lookup path, if a PATH= assignment
		 * is present
		 */
		for (sp = varlist.list; sp; sp = sp->next)
			if (strncmp(sp->text, PATH, sizeof(PATH) - 1) == 0)
				path = sp->text + sizeof(PATH) - 1;

		do {
			int argsused, use_syspath;
			find_command(psh, argv[0], &cmdentry, cmd_flags, path);
			if (cmdentry.cmdtype == CMDUNKNOWN) {
				psh->exitstatus = 127;
				flushout(&psh->errout);
				goto out;
			}

			/* implement the 'command' builtin here */
			if (cmdentry.cmdtype != CMDBUILTIN ||
			    cmdentry.u.bltin != bltincmd)
				break;
			cmd_flags |= DO_NOFUNC;
			argsused = parse_command_args(psh, argc, argv, &use_syspath);
			if (argsused == 0) {
				/* use 'type' builting to display info */
				cmdentry.u.bltin = typecmd;
				break;
			}
			argc -= argsused;
			argv += argsused;
			if (use_syspath)
				path = syspath(psh) + 5;
		} while (argc != 0);
		if (cmdentry.cmdtype == CMDSPLBLTIN && cmd_flags & DO_NOFUNC)
			/* posix mandates that 'command <splbltin>' act as if
			   <splbltin> was a normal builtin */
			cmdentry.cmdtype = CMDBUILTIN;
	}

	/* Fork off a child process if necessary. */
	if (cmd->ncmd.backgnd
	 || (cmdentry.cmdtype == CMDNORMAL && (flags & EV_EXIT) == 0)
	 || ((flags & EV_BACKCMD) != 0
	    && ((cmdentry.cmdtype != CMDBUILTIN && cmdentry.cmdtype != CMDSPLBLTIN)
		 || cmdentry.u.bltin == dotcmd
		 || cmdentry.u.bltin == evalcmd))) {
		INTOFF;
		jp = makejob(psh, cmd, 1);
		mode = cmd->ncmd.backgnd;
		if (flags & EV_BACKCMD) {
			mode = FORK_NOJOB;
			if (sh_pipe(psh, pip) < 0)
				error(psh, "Pipe call failed");
		}
#ifdef DO_SHAREDVFORK
		/* It is essential that if DO_SHAREDVFORK is defined that the
		 * child's address space is actually shared with the parent as
		 * we rely on this.
		 */
		if (cmdentry.cmdtype == CMDNORMAL) {
			pid_t	pid;

			savelocalvars = psh->localvars;
			psh->localvars = NULL;
			psh->vforked = 1;
			switch (pid = vfork()) {
			case -1:
				TRACE((psh, "Vfork failed, errno=%d\n", errno));
				INTON;
				error(psh, "Cannot vfork");
				break;
			case 0:
				/* Make sure that exceptions only unwind to
				 * after the vfork(2)
				 */
				if (setjmp(jmploc.loc)) {
					if (psh->exception == EXSHELLPROC) {
						/* We can't progress with the vfork,
						 * so, set vforked = 2 so the parent
						 * knows, and _exit();
						 */
						psh->vforked = 2;
						sh__exit(psh, 0);
					} else {
						sh__exit(psh, psh->exerrno);
					}
				}
				savehandler = psh->handler;
				psh->handler = &jmploc;
				listmklocal(psh, varlist.list, VEXPORT | VNOFUNC);
				forkchild(psh, jp, cmd, mode, psh->vforked);
				break;
			default:
				psh->handler = savehandler;	/* restore from vfork(2) */
				poplocalvars(psh);
				psh->localvars = savelocalvars;
				if (psh->vforked == 2) {
					psh->vforked = 0;

					(void)sh_waitpid(psh, pid, NULL, 0);
					/* We need to progress in a normal fork fashion */
					goto normal_fork;
				}
				psh->vforked = 0;
				forkparent(psh, jp, cmd, mode, pid);
				goto parent;
			}
		} else {
normal_fork:
#endif
			if (forkshell(psh, jp, cmd, mode) != 0)
				goto parent;	/* at end of routine */
			FORCEINTON;
#ifdef DO_SHAREDVFORK
		}
#endif
		if (flags & EV_BACKCMD) {
			if (!psh->vforked) {
				FORCEINTON;
			}
			shfile_close(&psh->fdtab, pip[0]);
			if (pip[1] != 1) {
				movefd(psh, pip[1], 1);
			}
		}
		flags |= EV_EXIT;
	}

	/* This is the child process if a fork occurred. */
	/* Execute the command. */
	switch (cmdentry.cmdtype) {
	case CMDFUNCTION:
#ifdef DEBUG
		trputs(psh, "Shell function:  ");  trargs(psh, argv);
#endif
		redirect(psh, cmd->ncmd.redirect, REDIR_PUSH);
		saveparam = psh->shellparam;
		psh->shellparam.malloc = 0;
		psh->shellparam.reset = 1;
		psh->shellparam.nparam = argc - 1;
		psh->shellparam.p = argv + 1;
		psh->shellparam.optnext = NULL;
		INTOFF;
		savelocalvars = psh->localvars;
		psh->localvars = NULL;
		INTON;
		if (setjmp(jmploc.loc)) {
			if (psh->exception == EXSHELLPROC) {
				freeparam(psh, (volatile struct shparam *)
				    &saveparam);
			} else {
				freeparam(psh, &psh->shellparam);
				psh->shellparam = saveparam;
			}
			poplocalvars(psh);
			psh->localvars = savelocalvars;
			psh->handler = savehandler;
			longjmp(psh->handler->loc, 1);
		}
		savehandler = psh->handler;
		psh->handler = &jmploc;
		listmklocal(psh, varlist.list, 0);
		/* stop shell blowing its stack */
		if (++psh->funcnest > 1000)
			error(psh, "too many nested function calls");
		evaltree(psh, cmdentry.u.func, flags & EV_TESTED);
		psh->funcnest--;
		INTOFF;
		poplocalvars(psh);
		psh->localvars = savelocalvars;
		freeparam(psh, &psh->shellparam);
		psh->shellparam = saveparam;
		psh->handler = savehandler;
		popredir(psh);
		INTON;
		if (psh->evalskip == SKIPFUNC) {
			psh->evalskip = 0;
			psh->skipcount = 0;
		}
		if (flags & EV_EXIT)
			exitshell(psh, psh->exitstatus);
		break;

	case CMDBUILTIN:
	case CMDSPLBLTIN:
#ifdef DEBUG
		trputs(psh, "builtin command:  ");  trargs(psh, argv);
#endif
		mode = (cmdentry.u.bltin == execcmd) ? 0 : REDIR_PUSH;
		if (flags == EV_BACKCMD) {
			psh->memout.nleft = 0;
			psh->memout.nextc = psh->memout.buf;
			psh->memout.bufsize = 64;
			mode |= REDIR_BACKQ;
		}
		e = -1;
		savehandler = psh->handler;
		savecmdname = psh->commandname;
		psh->handler = &jmploc;
		if (!setjmp(jmploc.loc)) {
			/* We need to ensure the command hash table isn't
			 * corruped by temporary PATH assignments.
			 * However we must ensure the 'local' command works!
			 */
			if (path != pathval(psh) && (cmdentry.u.bltin == hashcmd ||
			    cmdentry.u.bltin == typecmd)) {
				savelocalvars = psh->localvars;
				psh->localvars = 0;
				mklocal(psh, path - 5 /* PATH= */, 0);
				temp_path = 1;
			} else
				temp_path = 0;
			redirect(psh, cmd->ncmd.redirect, mode);

			/* exec is a special builtin, but needs this list... */
			psh->cmdenviron = varlist.list;
			/* we must check 'readonly' flag for all builtins */
			listsetvar(psh, varlist.list,
				cmdentry.cmdtype == CMDSPLBLTIN ? 0 : VNOSET);
			psh->commandname = argv[0];
			/* initialize nextopt */
			psh->argptr = argv + 1;
			psh->optptr = NULL;
			/* and getopt */
#if 0 /** @todo fix getop usage! */
#if defined(__FreeBSD__) || defined(__EMX__) || defined(__APPLE__)
			optreset = 1;
			optind = 1;
#else
			optind = 0; /* init */
#endif
#endif

			psh->exitstatus = cmdentry.u.bltin(psh, argc, argv);
		} else {
			e = psh->exception;
			psh->exitstatus = e == EXINT ? SIGINT + 128 :
					e == EXEXEC ? psh->exerrno : 2;
		}
		psh->handler = savehandler;
		output_flushall(psh);
		psh->out1 = &psh->output;
		psh->out2 = &psh->errout;
		freestdout(psh);
		if (temp_path) {
			poplocalvars(psh);
			psh->localvars = savelocalvars;
		}
		psh->cmdenviron = NULL;
		if (e != EXSHELLPROC) {
			psh->commandname = savecmdname;
			if (flags & EV_EXIT)
				exitshell(psh, psh->exitstatus);
		}
		if (e != -1) {
			if ((e != EXERROR && e != EXEXEC)
			    || cmdentry.cmdtype == CMDSPLBLTIN)
				exraise(psh, e);
			FORCEINTON;
		}
		if (cmdentry.u.bltin != execcmd)
			popredir(psh);
		if (flags == EV_BACKCMD) {
			backcmd->buf = psh->memout.buf;
			backcmd->nleft = (int)(psh->memout.nextc - psh->memout.buf);
			psh->memout.buf = NULL;
		}
		break;

	default:
#ifdef DEBUG
		trputs(psh, "normal command:  ");  trargs(psh, argv);
#endif
		clearredir(psh, psh->vforked);
		redirect(psh, cmd->ncmd.redirect, psh->vforked ? REDIR_VFORK : 0);
		if (!psh->vforked)
			for (sp = varlist.list ; sp ; sp = sp->next)
				setvareq(psh, sp->text, VEXPORT|VSTACK);
		envp = environment(psh);
		shellexec(psh, argv, envp, path, cmdentry.u.index, psh->vforked);
		break;
	}
	goto out;

parent:	/* parent process gets here (if we forked) */
	if (mode == FORK_FG) {	/* argument to fork */
		psh->exitstatus = waitforjob(psh, jp);
	} else if (mode == FORK_NOJOB) {
		backcmd->fd = pip[0];
		shfile_close(&psh->fdtab, pip[1]);
		backcmd->jp = jp;
	}
	FORCEINTON;

out:
	if (lastarg)
		/* dsl: I think this is intended to be used to support
		 * '_' in 'vi' command mode during line editing...
		 * However I implemented that within libedit itself.
		 */
		setvar(psh, "_", lastarg, 0);
	popstackmark(psh, &smark);

	if (eflag(psh) && psh->exitstatus && !(flags & EV_TESTED))
		exitshell(psh, psh->exitstatus);
}
예제 #10
0
파일: eval.c 프로젝트: dezelin/kBuild
void
evaltree(shinstance *psh, union node *n, int flags)
{
	if (n == NULL) {
		TRACE((psh, "evaltree(NULL) called\n"));
		psh->exitstatus = 0;
		goto out;
	}
#ifndef SMALL
	psh->displayhist = 1;	/* show history substitutions done with fc */
#endif
	TRACE((psh, "pid %d, evaltree(%p: %d, %d) called\n",
	       sh_getpid(psh), n, n->type, flags));
	switch (n->type) {
	case NSEMI:
		evaltree(psh, n->nbinary.ch1, flags & EV_TESTED);
		if (psh->evalskip)
			goto out;
		evaltree(psh, n->nbinary.ch2, flags);
		break;
	case NAND:
		evaltree(psh, n->nbinary.ch1, EV_TESTED);
		if (psh->evalskip || psh->exitstatus != 0)
			goto out;
		evaltree(psh, n->nbinary.ch2, flags);
		break;
	case NOR:
		evaltree(psh, n->nbinary.ch1, EV_TESTED);
		if (psh->evalskip || psh->exitstatus == 0)
			goto out;
		evaltree(psh, n->nbinary.ch2, flags);
		break;
	case NREDIR:
		expredir(psh, n->nredir.redirect);
		redirect(psh, n->nredir.redirect, REDIR_PUSH);
		evaltree(psh, n->nredir.n, flags);
		popredir(psh);
		break;
	case NSUBSHELL:
		evalsubshell(psh, n, flags);
		break;
	case NBACKGND:
		evalsubshell(psh, n, flags);
		break;
	case NIF: {
		evaltree(psh, n->nif.test, EV_TESTED);
		if (psh->evalskip)
			goto out;
		if (psh->exitstatus == 0)
			evaltree(psh, n->nif.ifpart, flags);
		else if (n->nif.elsepart)
			evaltree(psh, n->nif.elsepart, flags);
		else
			psh->exitstatus = 0;
		break;
	}
	case NWHILE:
	case NUNTIL:
		evalloop(psh, n, flags);
		break;
	case NFOR:
		evalfor(psh, n, flags);
		break;
	case NCASE:
		evalcase(psh, n, flags);
		break;
	case NDEFUN:
		defun(psh, n->narg.text, n->narg.next);
		psh->exitstatus = 0;
		break;
	case NNOT:
		evaltree(psh, n->nnot.com, EV_TESTED);
		psh->exitstatus = !psh->exitstatus;
		break;
	case NPIPE:
		evalpipe(psh, n);
		break;
	case NCMD:
		evalcommand(psh, n, flags, (struct backcmd *)NULL);
		break;
	default:
		out1fmt(psh, "Node type = %d\n", n->type);
		flushout(&psh->output);
		break;
	}
out:
	if (psh->pendingsigs)
		dotrap(psh);
	if ((flags & EV_EXIT) != 0)
		exitshell(psh, psh->exitstatus);
}
예제 #11
0
void
evaltree(union node *n, int flags)
{
	bool do_etest;

	do_etest = false;
	if (n == NULL || nflag) {
		TRACE(("evaltree(%s) called\n", n == NULL ? "NULL" : "-n"));
		if (nflag == 0)
			exitstatus = 0;
		goto out;
	}
#ifndef SMALL
	displayhist = 1;	/* show history substitutions done with fc */
#endif
#ifdef NODETYPENAME
	TRACE(("pid %d, evaltree(%p: %s(%d), %#x) called\n",
	    getpid(), n, NODETYPENAME(n->type), n->type, flags));
#else
	TRACE(("pid %d, evaltree(%p: %d, %#x) called\n",
	    getpid(), n, n->type, flags));
#endif
	switch (n->type) {
	case NSEMI:
		evaltree(n->nbinary.ch1, flags & EV_TESTED);
		if (nflag || evalskip)
			goto out;
		evaltree(n->nbinary.ch2, flags);
		break;
	case NAND:
		evaltree(n->nbinary.ch1, EV_TESTED);
		if (nflag || evalskip || exitstatus != 0)
			goto out;
		evaltree(n->nbinary.ch2, flags);
		break;
	case NOR:
		evaltree(n->nbinary.ch1, EV_TESTED);
		if (nflag || evalskip || exitstatus == 0)
			goto out;
		evaltree(n->nbinary.ch2, flags);
		break;
	case NREDIR:
		expredir(n->nredir.redirect);
		redirect(n->nredir.redirect, REDIR_PUSH | REDIR_KEEP);
		evaltree(n->nredir.n, flags);
		popredir();
		break;
	case NSUBSHELL:
		evalsubshell(n, flags);
		do_etest = !(flags & EV_TESTED);
		break;
	case NBACKGND:
		evalsubshell(n, flags);
		break;
	case NIF: {
		evaltree(n->nif.test, EV_TESTED);
		if (nflag || evalskip)
			goto out;
		if (exitstatus == 0)
			evaltree(n->nif.ifpart, flags);
		else if (n->nif.elsepart)
			evaltree(n->nif.elsepart, flags);
		else
			exitstatus = 0;
		break;
	}
	case NWHILE:
	case NUNTIL:
		evalloop(n, flags);
		break;
	case NFOR:
		evalfor(n, flags);
		break;
	case NCASE:
		evalcase(n, flags);
		break;
	case NDEFUN:
		defun(n->narg.text, n->narg.next);
		exitstatus = 0;
		break;
	case NNOT:
		evaltree(n->nnot.com, EV_TESTED);
		exitstatus = !exitstatus;
		break;
	case NPIPE:
		evalpipe(n);
		do_etest = !(flags & EV_TESTED);
		break;
	case NCMD:
		evalcommand(n, flags, NULL);
		do_etest = !(flags & EV_TESTED);
		break;
	default:
#ifdef NODETYPENAME
		out1fmt("Node type = %d(%s)\n", n->type, NODETYPENAME(n->type));
#else
		out1fmt("Node type = %d\n", n->type);
#endif
		flushout(&output);
		break;
	}
out:
	if (pendingsigs)
		dotrap();
	if ((flags & EV_EXIT) != 0 || (eflag && exitstatus != 0 && do_etest))
		exitshell(exitstatus);
}