[unix-history] / usr / src / bin / csh / sem.c

/*
 * Copyright (c) 1980 Regents of the University of California.
 * All rights reserved.  The Berkeley Software License Agreement
 * specifies the terms and conditions for redistribution.
 */

#ifndef lint
static char *sccsid = "@(#)sem.c	5.8 (Berkeley) %G%";
#endif

#include "sh.h"
#include "sh.proc.h"
#include <sys/file.h>
#include <sys/ioctl.h>
#include "pathnames.h"

/*
 * C shell
 */

static int nosigchld = 0, osigmask;
static int onosigchld = 0, oosigmask;
/*VARARGS 1*/
execute(t, wanttty, pipein, pipeout)
	register struct command *t;
	int wanttty, *pipein, *pipeout;
{
	bool forked = 0;
	struct biltins *bifunc;
	int pid = 0;
	int pv[2];

	if (t == 0)
		return;
	if ((t->t_dflg & FAND) && wanttty > 0)
		wanttty = 0;
	switch (t->t_dtyp) {

	case TCOM:
		if ((t->t_dcom[0][0] & (QUOTE|TRIM)) == QUOTE)
			(void) strcpy(t->t_dcom[0], t->t_dcom[0] + 1);
		if ((t->t_dflg & FREDO) == 0)
			Dfix(t);		/* $ " ' \ */
		if (t->t_dcom[0] == 0)
			return;
		/* fall into... */

	case TPAR:
		if (t->t_dflg & FPOU)
			mypipe(pipeout);
		/*
		 * Must do << early so parent will know
		 * where input pointer should be.
		 * If noexec then this is all we do.
		 */
		if (t->t_dflg & FHERE) {
			(void) close(0);
			heredoc(t->t_dlef);
			if (noexec)
				(void) close(0);
		}
		if (noexec)
			break;

		set("status", "0");

		/*
		 * This mess is the necessary kludge to handle the prefix
		 * builtins: nice, nohup, time.  These commands can also
		 * be used by themselves, and this is not handled here.
		 * This will also work when loops are parsed.
		 */
		while (t->t_dtyp == TCOM)
			if (eq(t->t_dcom[0], "nice"))
				if (t->t_dcom[1])
					if (any(t->t_dcom[1][0], "+-"))
						if (t->t_dcom[2]) {
							setname("nice");
							t->t_nice = getn(t->t_dcom[1]);
							lshift(t->t_dcom, 2);
							t->t_dflg |= FNICE;
						} else
							break;
					else {
						t->t_nice = 4;
						lshift(t->t_dcom, 1);
						t->t_dflg |= FNICE;
					}
				else
					break;
			else if (eq(t->t_dcom[0], "nohup"))
				if (t->t_dcom[1]) {
					t->t_dflg |= FNOHUP;
					lshift(t->t_dcom, 1);
				} else
					break;
			else if (eq(t->t_dcom[0], "time"))
				if (t->t_dcom[1]) {
					t->t_dflg |= FTIME;
					lshift(t->t_dcom, 1);
				} else
					break;
			else
				break;
		/*
		 * Check if we have a builtin function and remember which one.
		 */
		bifunc = t->t_dtyp == TCOM ? isbfunc(t) : (struct biltins *) 0;

		/*
		 * We fork only if we are timed, or are not the end of
		 * a parenthesized list and not a simple builtin function.
		 * Simple meaning one that is not pipedout, niced, nohupped,
		 * or &'d.
		 * It would be nice(?) to not fork in some of these cases.
		 */
		if (((t->t_dflg & FTIME) || (t->t_dflg & FPAR) == 0 &&
		     (!bifunc || t->t_dflg & (FPOU|FAND|FNICE|FNOHUP))))
#ifdef VFORK
		    if (t->t_dtyp == TPAR || t->t_dflg&(FREDO|FAND) || bifunc)
#endif
			{ forked++; 
			  if (wanttty >= 0 && !nosigchld) {
				osigmask = sigblock(sigmask(SIGCHLD));
				nosigchld = 1;
			  }

			  pid = pfork(t, wanttty);
			  if (pid == 0 && nosigchld) {
				sigsetmask(osigmask);
				nosigchld = 0;
			  }
			}
#ifdef VFORK
		    else {
			sig_t vffree;
			int ochild, osetintr, ohaderr, odidfds;
			int oSHIN, oSHOUT, oSHDIAG, oOLDSTD, otpgrp;
			long omask;

			/* 
			 * Prepare for the vfork by saving everything
			 * that the child corrupts before it exec's.
			 * Note that in some signal implementations
			 * which keep the signal info in user space
			 * (e.g. Sun's) it will also be necessary to
 			 * save and restore the current sigvec's for
			 * the signals the child touches before it
			 * exec's.
			 */
			if (wanttty >= 0 && !nosigchld && !noexec) {
				osigmask = sigblock(sigmask(SIGCHLD));
				nosigchld = 1;
			}
			omask = sigblock(sigmask(SIGCHLD));
			ochild = child; osetintr = setintr;
			ohaderr = haderr; odidfds = didfds;
			oSHIN = SHIN; oSHOUT = SHOUT;
			oSHDIAG = SHDIAG; oOLDSTD = OLDSTD; otpgrp = tpgrp;
			oosigmask = osigmask; onosigchld = nosigchld;
			Vsav = Vdp = 0; Vav = 0;
			pid = vfork();
			if (pid < 0) {
				(void) sigsetmask(omask);
				error("No more processes");
			}
			forked++;
			if (pid) {	/* parent */
				child = ochild; setintr = osetintr;
				haderr = ohaderr; didfds = odidfds;
				SHIN = oSHIN;
				SHOUT = oSHOUT; SHDIAG = oSHDIAG;
				OLDSTD = oOLDSTD; tpgrp = otpgrp;
				osigmask = oosigmask; nosigchld = onosigchld;
				xfree(Vsav); Vsav = 0;
				xfree(Vdp); Vdp = 0;
				xfree((char *)Vav); Vav = 0;
				/* this is from pfork() */
				palloc(pid, t);
				(void) sigsetmask(omask);
			} else {	/* child */
				/* this is from pfork() */
				int pgrp;
				bool ignint = 0;

				if (nosigchld) {
					sigsetmask(osigmask);
					nosigchld = 0;
				}
				if (setintr)
					ignint =
					    (tpgrp == -1 && (t->t_dflg&FINT))
					    || gointr && eq(gointr, "-");
				pgrp = pcurrjob ? pcurrjob->p_jobid : getpid();
				child++;
				if (setintr) {
					setintr = 0;
#ifdef notdef
					(void) signal(SIGCHLD, SIG_DFL);
#endif
					(void) signal(SIGINT, ignint ?
						SIG_IGN : vffree);
					(void) signal(SIGQUIT, ignint ?
						SIG_IGN : SIG_DFL);
					if (wanttty >= 0) {
						(void) signal(SIGTSTP, SIG_DFL);
						(void) signal(SIGTTIN, SIG_DFL);
						(void) signal(SIGTTOU, SIG_DFL);
					}
					(void) signal(SIGTERM, parterm);
				} else if (tpgrp == -1 && (t->t_dflg&FINT)) {
					(void) signal(SIGINT, SIG_IGN);
					(void) signal(SIGQUIT, SIG_IGN);
				}
				if (wanttty >= 0 && tpgrp >= 0)
					(void) setpgrp(0, pgrp);
				if (wanttty > 0)
					(void) ioctl(FSHTTY, TIOCSPGRP,
						(char *)&pgrp);
				if (tpgrp > 0)
					tpgrp = 0;
				if (t->t_dflg & FNOHUP)
					(void) signal(SIGHUP, SIG_IGN);
				if (t->t_dflg & FNICE)
					(void) setpriority(PRIO_PROCESS,
						0, t->t_nice);
			}

		    }
#endif
		if (pid != 0) {
			/*
			 * It would be better if we could wait for the
			 * whole job when we knew the last process
			 * had been started.  Pwait, in fact, does
			 * wait for the whole job anyway, but this test
			 * doesn't really express our intentions.
			 */
			if (didfds==0 && t->t_dflg&FPIN) {
				(void) close(pipein[0]);
				(void) close(pipein[1]);
			}
			if ((t->t_dflg & FPOU) == 0) {
				if (nosigchld) {
#ifdef foobarbaz
					printf("DID\n");
#endif
					sigsetmask(osigmask);
					nosigchld = 0;
				}
				if ((t->t_dflg & FAND) == 0)
					pwait();
			}
			break;
		}
		doio(t, pipein, pipeout);
		if (t->t_dflg & FPOU) {
			(void) close(pipeout[0]);
			(void) close(pipeout[1]);
		}

		/*
		 * Perform a builtin function.
		 * If we are not forked, arrange for possible stopping
		 */
		if (bifunc) {
			func(t, bifunc);
			if (forked)
				exitstat();
			break;
		}
		if (t->t_dtyp != TPAR) {
			doexec(t);
			/*NOTREACHED*/
		}
		/*
		 * For () commands must put new 0,1,2 in FSH* and recurse
		 */
		OLDSTD = dcopy(0, FOLDSTD);
		SHOUT = dcopy(1, FSHOUT);
		SHDIAG = dcopy(2, FSHDIAG);
		(void) close(SHIN);
		SHIN = -1;
		didfds = 0;
		wanttty = -1;
		t->t_dspr->t_dflg |= t->t_dflg & FINT;
		execute(t->t_dspr, wanttty);
		exitstat();

	case TFIL:
		t->t_dcar->t_dflg |= FPOU |
		    (t->t_dflg & (FPIN|FAND|FDIAG|FINT));
		execute(t->t_dcar, wanttty, pipein, pv);
		t->t_dcdr->t_dflg |= FPIN |
		    (t->t_dflg & (FPOU|FAND|FPAR|FINT));
		if (wanttty > 0)
			wanttty = 0;		/* got tty already */
		execute(t->t_dcdr, wanttty, pv, pipeout);
		break;

	case TLST:
		if (t->t_dcar) {
			t->t_dcar->t_dflg |= t->t_dflg & FINT;
			execute(t->t_dcar, wanttty);
			/*
			 * In strange case of A&B make a new job after A
			 */
			if (t->t_dcar->t_dflg&FAND && t->t_dcdr &&
			    (t->t_dcdr->t_dflg&FAND) == 0)
				pendjob();
		}
		if (t->t_dcdr) {
			t->t_dcdr->t_dflg |= t->t_dflg & (FPAR|FINT);
			execute(t->t_dcdr, wanttty);
		}
		break;

	case TOR:
	case TAND:
		if (t->t_dcar) {
			t->t_dcar->t_dflg |= t->t_dflg & FINT;
			execute(t->t_dcar, wanttty);
			if ((getn(value("status")) == 0) != (t->t_dtyp == TAND))
				return;
		}
		if (t->t_dcdr) {
			t->t_dcdr->t_dflg |= t->t_dflg & (FPAR|FINT);
			execute(t->t_dcdr, wanttty);
		}
		break;
	}
	/*
	 * Fall through for all breaks from switch
	 *
	 * If there will be no more executions of this
	 * command, flush all file descriptors.
	 * Places that turn on the FREDO bit are responsible
	 * for doing donefds after the last re-execution
	 */
	if (didfds && !(t->t_dflg & FREDO))
		donefds();
}

#ifdef VFORK
vffree()
{
	register char **v;

	if (v = gargv)
		gargv = 0, xfree((char *)v);
	if (v = pargv)
		pargv = 0, xfree((char *)v);
	_exit(1);
}
#endif

/*
 * Perform io redirection.
 * We may or maynot be forked here.
 */
doio(t, pipein, pipeout)
	register struct command *t;
	int *pipein, *pipeout;
{
	register char *cp;
	register int flags = t->t_dflg;

	if (didfds || (flags & FREDO))
		return;
	if ((flags & FHERE) == 0) {	/* FHERE already done */
		(void) close(0);
		if (cp = t->t_dlef) {
			cp = globone(Dfix1(cp));
			xfree(cp);
			if (open(cp, 0) < 0)
				Perror(cp);
		} else if (flags & FPIN) {
			(void) dup(pipein[0]);
			(void) close(pipein[0]);
			(void) close(pipein[1]);
		} else if ((flags & FINT) && tpgrp == -1) {
			(void) close(0);
			(void) open(_PATH_DEVNULL, 0);
		} else
			(void) dup(OLDSTD);
	}
	(void) close(1);
	if (cp = t->t_drit) {
		cp = globone(Dfix1(cp));
		xfree(cp);
		if (!(flags & FCAT) || open(cp, O_WRONLY|O_APPEND, 0) < 0) {
			if (!(flags & FANY) && adrof("noclobber")) {
				if (flags & FCAT)
					Perror(cp);
				chkclob(cp);
			}
			if (creat(cp, 0666) < 0)
				Perror(cp);
		}
	} else if (flags & FPOU)
		(void) dup(pipeout[1]);
	else
		(void) dup(SHOUT);

	(void) close(2);
	if (flags & FDIAG)
		(void) dup(1);
	else
		(void) dup(SHDIAG);
	didfds = 1;
}

mypipe(pv)
	register int *pv;
{

	if (pipe(pv) < 0)
		goto oops;
	pv[0] = dmove(pv[0], -1);
	pv[1] = dmove(pv[1], -1);
	if (pv[0] >= 0 && pv[1] >= 0)
		return;
oops:
	error("Can't make pipe");
}

chkclob(cp)
	register char *cp;
{
	struct stat stb;

	if (stat(cp, &stb) < 0)
		return;
	if ((stb.st_mode & S_IFMT) == S_IFCHR)
		return;
	error("%s: File exists", cp);
}
Commit	Line	Data
b79f4fa9 DF	1	/*
b79f4fa9 DF	2	* Copyright (c) 1980 Regents of the University of California.
094e80ed	3	* All rights reserved. The Berkeley Software License Agreement
b79f4fa9 DF	4	* specifies the terms and conditions for redistribution.
	5	*/
	6
35371dec	7	#ifndef lint
21787e35	8	static char *sccsid = "@(#)sem.c 5.8 (Berkeley) %G%";
094e80ed	9	#endif
e0cb907a BJ	10
	11	#include "sh.h"
	12	#include "sh.proc.h"
21787e35	13	#include <sys/file.h>
e0cb907a	14	#include <sys/ioctl.h>
85443bfb	15	#include "pathnames.h"
e0cb907a BJ	16
	17	/*
	18	* C shell
	19	*/
	20
85443bfb MT	21	static int nosigchld = 0, osigmask;
85443bfb MT	22	static int onosigchld = 0, oosigmask;
e0cb907a BJ	23	/VARARGS 1/
	24	execute(t, wanttty, pipein, pipeout)
	25	register struct command *t;
	26	int wanttty, pipein, pipeout;
	27	{
	28	bool forked = 0;
	29	struct biltins *bifunc;
	30	int pid = 0;
	31	int pv[2];
	32
	33	if (t == 0)
	34	return;
	35	if ((t->t_dflg & FAND) && wanttty > 0)
	36	wanttty = 0;
	37	switch (t->t_dtyp) {
	38
	39	case TCOM:
	40	if ((t->t_dcom[0][0] & (QUOTE\|TRIM)) == QUOTE)
35371dec	41	(void) strcpy(t->t_dcom[0], t->t_dcom[0] + 1);
e0cb907a BJ	42	if ((t->t_dflg & FREDO) == 0)
	43	Dfix(t); /* $ " ' \ */
	44	if (t->t_dcom[0] == 0)
	45	return;
	46	/* fall into... */
	47
	48	case TPAR:
	49	if (t->t_dflg & FPOU)
	50	mypipe(pipeout);
	51	/*
	52	* Must do << early so parent will know
	53	* where input pointer should be.
	54	* If noexec then this is all we do.
	55	*/
	56	if (t->t_dflg & FHERE) {
35371dec	57	(void) close(0);
e0cb907a BJ	58	heredoc(t->t_dlef);
e0cb907a BJ	59	if (noexec)
35371dec	60	(void) close(0);
e0cb907a BJ	61	}
	62	if (noexec)
	63	break;
	64
	65	set("status", "0");
	66
	67	/*
	68	* This mess is the necessary kludge to handle the prefix
	69	* builtins: nice, nohup, time. These commands can also
	70	* be used by themselves, and this is not handled here.
	71	* This will also work when loops are parsed.
	72	*/
	73	while (t->t_dtyp == TCOM)
	74	if (eq(t->t_dcom[0], "nice"))
	75	if (t->t_dcom[1])
	76	if (any(t->t_dcom[1][0], "+-"))
	77	if (t->t_dcom[2]) {
	78	setname("nice");
	79	t->t_nice = getn(t->t_dcom[1]);
	80	lshift(t->t_dcom, 2);
	81	t->t_dflg \|= FNICE;
	82	} else
	83	break;
	84	else {
	85	t->t_nice = 4;
	86	lshift(t->t_dcom, 1);
	87	t->t_dflg \|= FNICE;
	88	}
	89	else
	90	break;
	91	else if (eq(t->t_dcom[0], "nohup"))
	92	if (t->t_dcom[1]) {
	93	t->t_dflg \|= FNOHUP;
	94	lshift(t->t_dcom, 1);
	95	} else
	96	break;
	97	else if (eq(t->t_dcom[0], "time"))
	98	if (t->t_dcom[1]) {
	99	t->t_dflg \|= FTIME;
	100	lshift(t->t_dcom, 1);
	101	} else
	102	break;
	103	else
	104	break;
	105	/*
	106	* Check if we have a builtin function and remember which one.
	107	*/
	108	bifunc = t->t_dtyp == TCOM ? isbfunc(t) : (struct biltins *) 0;
	109
	110	/*
	111	* We fork only if we are timed, or are not the end of
	112	* a parenthesized list and not a simple builtin function.
	113	* Simple meaning one that is not pipedout, niced, nohupped,
	114	* or &'d.
	115	* It would be nice(?) to not fork in some of these cases.
	116	*/
	117	if (((t->t_dflg & FTIME) \|\| (t->t_dflg & FPAR) == 0 &&
	118	(!bifunc \|\| t->t_dflg & (FPOU\|FAND\|FNICE\|FNOHUP))))
	119	#ifdef VFORK
	120	if (t->t_dtyp == TPAR \|\| t->t_dflg&(FREDO\|FAND) \|\| bifunc)
	121	#endif
85443bfb MT	122	{ forked++;
85443bfb MT	123	if (wanttty >= 0 && !nosigchld) {
85443bfb MT	124	osigmask = sigblock(sigmask(SIGCHLD));
	125	nosigchld = 1;
	126	}
	127
	128	pid = pfork(t, wanttty);
	129	if (pid == 0 && nosigchld) {
85443bfb MT	130	sigsetmask(osigmask);
	131	nosigchld = 0;
	132	}
	133	}
e0cb907a BJ	134	#ifdef VFORK
e0cb907a BJ	135	else {
85443bfb	136	sig_t vffree;
35371dec	137	int ochild, osetintr, ohaderr, odidfds;
e0cb907a	138	int oSHIN, oSHOUT, oSHDIAG, oOLDSTD, otpgrp;
1f7b623f	139	long omask;
e0cb907a	140
e9c261bb JL	141	/*
	142	* Prepare for the vfork by saving everything
	143	* that the child corrupts before it exec's.
	144	* Note that in some signal implementations
	145	* which keep the signal info in user space
	146	* (e.g. Sun's) it will also be necessary to
	147	* save and restore the current sigvec's for
	148	* the signals the child touches before it
	149	* exec's.
	150	*/
85443bfb	151	if (wanttty >= 0 && !nosigchld && !noexec) {
85443bfb MT	152	osigmask = sigblock(sigmask(SIGCHLD));
	153	nosigchld = 1;
	154	}
d33af40e	155	omask = sigblock(sigmask(SIGCHLD));
e0cb907a	156	ochild = child; osetintr = setintr;
35371dec	157	ohaderr = haderr; odidfds = didfds;
e0cb907a BJ	158	oSHIN = SHIN; oSHOUT = SHOUT;
e0cb907a BJ	159	oSHDIAG = SHDIAG; oOLDSTD = OLDSTD; otpgrp = tpgrp;
85443bfb	160	oosigmask = osigmask; onosigchld = nosigchld;
e0cb907a BJ	161	Vsav = Vdp = 0; Vav = 0;
	162	pid = vfork();
	163	if (pid < 0) {
35371dec	164	(void) sigsetmask(omask);
e0cb907a BJ	165	error("No more processes");
	166	}
	167	forked++;
e9c261bb	168	if (pid) { /* parent */
e0cb907a BJ	169	child = ochild; setintr = osetintr;
e0cb907a BJ	170	haderr = ohaderr; didfds = odidfds;
35371dec	171	SHIN = oSHIN;
e0cb907a BJ	172	SHOUT = oSHOUT; SHDIAG = oSHDIAG;
e0cb907a BJ	173	OLDSTD = oOLDSTD; tpgrp = otpgrp;
85443bfb	174	osigmask = oosigmask; nosigchld = onosigchld;
e0cb907a BJ	175	xfree(Vsav); Vsav = 0;
e0cb907a BJ	176	xfree(Vdp); Vdp = 0;
35371dec	177	xfree((char *)Vav); Vav = 0;
e0cb907a BJ	178	/* this is from pfork() */
e0cb907a BJ	179	palloc(pid, t);
35371dec	180	(void) sigsetmask(omask);
e9c261bb	181	} else { /* child */
e0cb907a BJ	182	/* this is from pfork() */
	183	int pgrp;
	184	bool ignint = 0;
	185
85443bfb	186	if (nosigchld) {
85443bfb MT	187	sigsetmask(osigmask);
	188	nosigchld = 0;
	189	}
e0cb907a BJ	190	if (setintr)
	191	ignint =
	192	(tpgrp == -1 && (t->t_dflg&FINT))
	193	\|\| gointr && eq(gointr, "-");
	194	pgrp = pcurrjob ? pcurrjob->p_jobid : getpid();
	195	child++;
	196	if (setintr) {
	197	setintr = 0;
ec1a81af	198	#ifdef notdef
35371dec	199	(void) signal(SIGCHLD, SIG_DFL);
ec1a81af	200	#endif
35371dec	201	(void) signal(SIGINT, ignint ?
d33af40e	202	SIG_IGN : vffree);
35371dec	203	(void) signal(SIGQUIT, ignint ?
d33af40e	204	SIG_IGN : SIG_DFL);
e0cb907a	205	if (wanttty >= 0) {
35371dec EW	206	(void) signal(SIGTSTP, SIG_DFL);
	207	(void) signal(SIGTTIN, SIG_DFL);
	208	(void) signal(SIGTTOU, SIG_DFL);
e0cb907a	209	}
35371dec	210	(void) signal(SIGTERM, parterm);
e0cb907a	211	} else if (tpgrp == -1 && (t->t_dflg&FINT)) {
35371dec EW	212	(void) signal(SIGINT, SIG_IGN);
35371dec EW	213	(void) signal(SIGQUIT, SIG_IGN);
e0cb907a	214	}
85443bfb MT	215	if (wanttty >= 0 && tpgrp >= 0)
85443bfb MT	216	(void) setpgrp(0, pgrp);
e0cb907a	217	if (wanttty > 0)
35371dec EW	218	(void) ioctl(FSHTTY, TIOCSPGRP,
35371dec EW	219	(char *)&pgrp);
e0cb907a BJ	220	if (tpgrp > 0)
	221	tpgrp = 0;
	222	if (t->t_dflg & FNOHUP)
35371dec	223	(void) signal(SIGHUP, SIG_IGN);
e0cb907a	224	if (t->t_dflg & FNICE)
e9c261bb JL	225	(void) setpriority(PRIO_PROCESS,
e9c261bb JL	226	0, t->t_nice);
e0cb907a BJ	227	}
e0cb907a BJ	228
d33af40e	229	}
e0cb907a BJ	230	#endif
	231	if (pid != 0) {
	232	/*
	233	* It would be better if we could wait for the
	234	* whole job when we knew the last process
	235	* had been started. Pwait, in fact, does
	236	* wait for the whole job anyway, but this test
	237	* doesn't really express our intentions.
	238	*/
35371dec EW	239	if (didfds==0 && t->t_dflg&FPIN) {
	240	(void) close(pipein[0]);
	241	(void) close(pipein[1]);
	242	}
85443bfb	243	if ((t->t_dflg & FPOU) == 0) {
85443bfb MT	244	if (nosigchld) {
	245	#ifdef foobarbaz
	246	printf("DID\n");
	247	#endif
	248	sigsetmask(osigmask);
	249	nosigchld = 0;
	250	}
	251	if ((t->t_dflg & FAND) == 0)
	252	pwait();
	253	}
e0cb907a BJ	254	break;
	255	}
	256	doio(t, pipein, pipeout);
35371dec EW	257	if (t->t_dflg & FPOU) {
	258	(void) close(pipeout[0]);
	259	(void) close(pipeout[1]);
	260	}
e0cb907a BJ	261
	262	/*
	263	* Perform a builtin function.
	264	* If we are not forked, arrange for possible stopping
	265	*/
	266	if (bifunc) {
	267	func(t, bifunc);
	268	if (forked)
	269	exitstat();
	270	break;
	271	}
	272	if (t->t_dtyp != TPAR) {
	273	doexec(t);
	274	/NOTREACHED/
	275	}
	276	/*
	277	* For () commands must put new 0,1,2 in FSH* and recurse
	278	*/
	279	OLDSTD = dcopy(0, FOLDSTD);
	280	SHOUT = dcopy(1, FSHOUT);
	281	SHDIAG = dcopy(2, FSHDIAG);
35371dec EW	282	(void) close(SHIN);
	283	SHIN = -1;
	284	didfds = 0;
e0cb907a BJ	285	wanttty = -1;
	286	t->t_dspr->t_dflg \|= t->t_dflg & FINT;
	287	execute(t->t_dspr, wanttty);
	288	exitstat();
	289
	290	case TFIL:
	291	t->t_dcar->t_dflg \|= FPOU \|
	292	(t->t_dflg & (FPIN\|FAND\|FDIAG\|FINT));
	293	execute(t->t_dcar, wanttty, pipein, pv);
	294	t->t_dcdr->t_dflg \|= FPIN \|
	295	(t->t_dflg & (FPOU\|FAND\|FPAR\|FINT));
	296	if (wanttty > 0)
	297	wanttty = 0; /* got tty already */
	298	execute(t->t_dcdr, wanttty, pv, pipeout);
	299	break;
	300
	301	case TLST:
	302	if (t->t_dcar) {
	303	t->t_dcar->t_dflg \|= t->t_dflg & FINT;
	304	execute(t->t_dcar, wanttty);
	305	/*
	306	* In strange case of A&B make a new job after A
	307	*/
	308	if (t->t_dcar->t_dflg&FAND && t->t_dcdr &&
	309	(t->t_dcdr->t_dflg&FAND) == 0)
	310	pendjob();
	311	}
	312	if (t->t_dcdr) {
	313	t->t_dcdr->t_dflg \|= t->t_dflg & (FPAR\|FINT);
	314	execute(t->t_dcdr, wanttty);
	315	}
	316	break;
	317
	318	case TOR:
	319	case TAND:
	320	if (t->t_dcar) {
	321	t->t_dcar->t_dflg \|= t->t_dflg & FINT;
	322	execute(t->t_dcar, wanttty);
	323	if ((getn(value("status")) == 0) != (t->t_dtyp == TAND))
	324	return;
	325	}
	326	if (t->t_dcdr) {
	327	t->t_dcdr->t_dflg \|= t->t_dflg & (FPAR\|FINT);
	328	execute(t->t_dcdr, wanttty);
	329	}
	330	break;
	331	}
	332	/*
	333	* Fall through for all breaks from switch
	334	*
	335	* If there will be no more executions of this
	336	* command, flush all file descriptors.
	337	* Places that turn on the FREDO bit are responsible
	338	* for doing donefds after the last re-execution
	339	*/
	340	if (didfds && !(t->t_dflg & FREDO))
	341	donefds();
	342	}
	343
	344	#ifdef VFORK
	345	vffree()
	346	{
	347	register char **v;
	348
349	if (v = gargv)
35371dec	350	gargv = 0, xfree((char *)v);
e0cb907a	351	if (v = pargv)
35371dec	352	pargv = 0, xfree((char *)v);
e0cb907a BJ	353	_exit(1);
	354	}
	355	#endif
	356
	357	/*
	358	* Perform io redirection.
	359	* We may or maynot be forked here.
	360	*/
	361	doio(t, pipein, pipeout)
	362	register struct command *t;
	363	int pipein, pipeout;
	364	{
	365	register char *cp;
	366	register int flags = t->t_dflg;
	367
	368	if (didfds \|\| (flags & FREDO))
	369	return;
	370	if ((flags & FHERE) == 0) { /* FHERE already done */
35371dec	371	(void) close(0);
e0cb907a BJ	372	if (cp = t->t_dlef) {
	373	cp = globone(Dfix1(cp));
	374	xfree(cp);
	375	if (open(cp, 0) < 0)
	376	Perror(cp);
35371dec EW	377	} else if (flags & FPIN) {
	378	(void) dup(pipein[0]);
	379	(void) close(pipein[0]);
	380	(void) close(pipein[1]);
	381	} else if ((flags & FINT) && tpgrp == -1) {
	382	(void) close(0);
85443bfb	383	(void) open(_PATH_DEVNULL, 0);
35371dec	384	} else
d671c35e	385	(void) dup(OLDSTD);
e0cb907a	386	}
35371dec	387	(void) close(1);
e0cb907a BJ	388	if (cp = t->t_drit) {
	389	cp = globone(Dfix1(cp));
	390	xfree(cp);
21787e35	391	if (!(flags & FCAT) \|\| open(cp, O_WRONLY\|O_APPEND, 0) < 0) {
e0cb907a BJ	392	if (!(flags & FANY) && adrof("noclobber")) {
	393	if (flags & FCAT)
	394	Perror(cp);
	395	chkclob(cp);
	396	}
	397	if (creat(cp, 0666) < 0)
	398	Perror(cp);
	399	}
	400	} else if (flags & FPOU)
35371dec	401	(void) dup(pipeout[1]);
e0cb907a	402	else
d671c35e	403	(void) dup(SHOUT);
e0cb907a	404
35371dec EW	405	(void) close(2);
	406	if (flags & FDIAG)
	407	(void) dup(1);
	408	else
d671c35e	409	(void) dup(SHDIAG);
e0cb907a BJ	410	didfds = 1;
	411	}
	412
	413	mypipe(pv)
	414	register int *pv;
	415	{
	416
	417	if (pipe(pv) < 0)
	418	goto oops;
	419	pv[0] = dmove(pv[0], -1);
	420	pv[1] = dmove(pv[1], -1);
	421	if (pv[0] >= 0 && pv[1] >= 0)
	422	return;
	423	oops:
	424	error("Can't make pipe");
	425	}
	426
	427	chkclob(cp)
	428	register char *cp;
	429	{
	430	struct stat stb;
	431
	432	if (stat(cp, &stb) < 0)
	433	return;
	434	if ((stb.st_mode & S_IFMT) == S_IFCHR)
	435	return;
	436	error("%s: File exists", cp);
	437	}