#include "rc.h"#include "getflags.h"#include "exec.h"#include "io.h"#include "fns.h" int havefork = 1;int pids[8192];int pidp = 0;int pipep = 0;extern int npipe; #define	pushmp(x) ((pipep!=npipe || morempipes()), mpstk[pipep] = (x), pipep++) pipes*popmp(void){	if(pipep==0)		return nil;	return mpstk[--pipep];} intmorempipes(void){	npipe+=10;	mpstk = (pipes **)realloc((char *)mpstk, npipe*sizeof mpstk[0]);	if(mpstk==0)		panic("Can't realloc %d bytes in morempipes!",				npipe*sizeof mpstk[0]);	return 0;} voidXasync(void){	int null = open("/dev/null", 0);	int pid;	char npid[10];	if(null<0){		Xerror("Can't open /dev/null\n");		return;	}	switch(pid = rfork(RFFDG|RFPROC|RFNOTEG)){	case -1:		close(null);		Xerror("try again");		break;	case 0:		clearwaitpids();		pushredir(ROPEN, null, 0);		start(runq->code, runq->pc+1, runq->local);		runq->ret = 0;		break;	default:		addwaitpid(pid);		close(null);		runq->pc = runq->code[runq->pc].i;		inttoascii(npid, pid);		setvar("apid", newword(npid, (word *)0));		break;	}} voidXpipe(void){	struct thread *p = runq;	int pc = p->pc, forkid;	int lfd = p->code[pc++].i;	int rfd = p->code[pc++].i;	int pfd[2];	if(pipe(pfd)<0){		Xerror("can't get pipe");		return;	}	switch(forkid = fork()){	case -1:		Xerror("try again");		break;	case 0:		clearwaitpids();		start(p->code, pc+2, runq->local);		runq->ret = 0;		close(pfd[PRD]);		pushredir(ROPEN, pfd[PWR], lfd);		break;	default:		addwaitpid(forkid);		start(p->code, p->code[pc].i, runq->local);		close(pfd[PWR]);		pushredir(ROPEN, pfd[PRD], rfd);		p->pc = p->code[pc+1].i;		p->pid = forkid;		break;	}} voidXfanin(void){	int i, j;	char s[40];	struct thread *p = runq;	int pc = p->pc, forkid;	int lfd = p->code[pc++].i;	int nfd = p->code[pc++].i;	int pfd[2];		static int ntimes;	nfd = 3; // XXX: to test	pipes *m = emalloc(sizeof(pipes)+nfd * sizeof(int) * 2);	m->npipe = nfd;	for(i = 0; i < m->npipe; i++)		for(j = 0; j < 2; j++)			if(pipe(m->fd[i][j])<0){				Xerror("can't get pipe");				return;			}		pushmp(m);	if(pipe(pfd)<0){		Xerror("can't get pipe");		return;	}	// IRF	switch(forkid = fork()){	case -1:		Xerror("try again");		break;	case 0:		clearwaitpids();		pushlist();		for(i = 0; i < m->npipe; i++){			close(m->fd[i][1][PWR]);			close(m->fd[i][0][PRD]);			close(m->fd[i][0][PWR]);			pushword(smprint("%d", m->fd[i][1][PRD]));		}		startargv(p->code, pc+3, runq->local, runq->argv);		runq->ret = 0;		close(pfd[PRD]);		close(0); // irf doesn't need a stdin. 		pushredir(ROPEN, pfd[PWR], 1);		return;	default:		addwaitpid(forkid);		break;	}	switch(forkid = fork()){	case -1:		Xerror("try again");		break;	case 0:		clearwaitpids();		start(p->code, p->code[pc+1].i, runq->local);		for(i = 0; i < m->npipe; i++){			for(j = 0; j < 2; j++){				close(m->fd[i][j][PRD]);				close(m->fd[i][j][PWR]);			}		} 		close(pfd[PWR]);		pushredir(ROPEN, pfd[PRD], 0);			runq->ret = 0;		return;	default:		addwaitpid(forkid);		break;		} 	start(p->code, p->code[pc].i, runq->local);	close(pfd[PWR]);	close(pfd[PRD]); 	p->pc = p->code[pc+1].i;} voidXfanout(void){	int i, j, k;	char s[40];	struct thread *p = runq;	int pc = p->pc, forkid;	int lfd = p->code[pc++].i;	int rfd = p->code[pc++].i;	int pfd[2];	pipes *m = popmp(); 	if(m == nil)		Xerror("no multipipes on stack");		if(pipe(pfd)<0){		Xerror("can't get pipe");		return;	}	// ORF	switch(forkid = fork()){	case -1:		Xerror("try again");		break;	case 0:		clearwaitpids();		pushlist();		for(i = 0; i < m->npipe; i++){			pushword(smprint("%d", m->fd[i][0][PWR]));		}		startargv(p->code, pc+3, runq->local, runq->argv);		runq->ret = 0;		for(i = 0; i < m->npipe; i++){			close(m->fd[i][1][PRD]);			close(m->fd[i][1][PWR]);			close(m->fd[i][0][PRD]); 		} 				close(pfd[PWR]);		close(1); // orf doesn't need a stdout.		pushredir(ROPEN, pfd[PRD], 0);		return;	default:		addwaitpid(forkid);		break;	}	for(i = 0; i < m->npipe; i++) switch(forkid = fork()){	case -1:		Xerror("try again");		break;	case 0:		clearwaitpids();		start(p->code, p->code[pc+1].i, runq->local);		runq->ret = 0;		close(pfd[PRD]);		close(pfd[PWR]);		for(j = 0; j < m->npipe; j++){			if(j == i)				continue;			for(k = 0; k < 2; k++){				close(m->fd[j][k][PWR]);				close(m->fd[j][k][PRD]);			}		}		close(m->fd[i][0][PWR]);		close(m->fd[i][1][PRD]);		pushredir(ROPEN, m->fd[i][0][PRD], 0);		pushredir(ROPEN, m->fd[i][1][PWR], 1);		return;	default:		addwaitpid(forkid);		break;		}		start(p->code, p->code[pc].i, runq->local);	for(i = 0; i < m->npipe; i++){		for(j = 0; j < 2; j++){			close(m->fd[i][j][PRD]);			close(m->fd[i][j][PWR]);		}	} 	close(pfd[PRD]); 	pushredir(ROPEN, pfd[PWR], 1);	p->pc = p->code[pc+1].i;	p->pid = forkid;} enum { Wordmax = 8192, }; /* * Who should wait for the exit from the fork? */voidXbackq(void){	int c, pid;	int pfd[2];	char wd[Wordmax + 1];	char *s, *ewd = &wd[Wordmax], *stop;	struct io *f;	var *ifs = vlook("ifs");	word *v, *nextv; 	stop = ifs->val? ifs->val->word: "";	if(pipe(pfd)<0){		Xerror("can't make pipe");		return;	}	switch(pid = fork()){	case -1:		Xerror("try again");		close(pfd[PRD]);		close(pfd[PWR]);		return;	case 0:		clearwaitpids();		close(pfd[PRD]);		start(runq->code, runq->pc+1, runq->local);		pushredir(ROPEN, pfd[PWR], 1);		return;	default:		addwaitpid(pid);		close(pfd[PWR]);		f = openfd(pfd[PRD]);		s = wd;		v = 0;		/*		 * this isn't quite right for utf.  stop could have utf		 * in it, and we're processing the input as bytes, not		 * utf encodings of runes.  further, if we run out of		 * room in wd, we can chop in the middle of a utf encoding		 * (not to mention stepping on one of the bytes).		 * presotto's Strings seem like the right data structure here.		 */		while((c = rchr(f))!=EOF){			if(strchr(stop, c) || s==ewd){				if(s!=wd){					*s='\0';					v = newword(wd, v);					s = wd;				}			}			else *s++=c;		}		if(s!=wd){			*s='\0';			v = newword(wd, v);		}		closeio(f);		Waitfor(pid, 0);		/* v points to reversed arglist -- reverse it onto argv */		while(v){			nextv = v->next;			v->next = runq->argv->words;			runq->argv->words = v;			v = nextv;		}		runq->pc = runq->code[runq->pc].i;		return;	}} voidXpipefd(void){	struct thread *p = runq;	int pc = p->pc, pid;	char name[40];	int pfd[2];	int sidefd, mainfd;	if(pipe(pfd)<0){		Xerror("can't get pipe");		return;	}	if(p->code[pc].i==READ){		sidefd = pfd[PWR];		mainfd = pfd[PRD];	}	else{		sidefd = pfd[PRD];		mainfd = pfd[PWR];	}	switch(pid = fork()){	case -1:		Xerror("try again");		break;	case 0:		clearwaitpids();		start(p->code, pc+2, runq->local);		close(mainfd);		pushredir(ROPEN, sidefd, p->code[pc].i==READ?1:0);		runq->ret = 0;		break;	default:		addwaitpid(pid);		close(sidefd);		pushredir(ROPEN, mainfd, mainfd);	/* isn't this a noop? */		strcpy(name, Fdprefix);		inttoascii(name+strlen(name), mainfd);		pushword(name);		p->pc = p->code[pc+1].i;		break;	}} voidXsubshell(void){	int pid;	switch(pid = fork()){	case -1:		Xerror("try again");		break;	case 0:		clearwaitpids();		start(runq->code, runq->pc+1, runq->local);		runq->ret = 0;		break;	default:		addwaitpid(pid);		Waitfor(pid, 1);		runq->pc = runq->code[runq->pc].i;		break;	}} intexecforkexec(void){	int pid;	int n;	char buf[ERRMAX]; 	switch(pid = fork()){	case -1:		return -1;	case 0:		clearwaitpids();		pushword("exec");		execexec();		strcpy(buf, "can't exec: ");		n = strlen(buf);		errstr(buf+n, ERRMAX-n);		Exit(buf);	}	addwaitpid(pid);	return pid;}