/*  * This file is part of the UCB release of Plan 9. It is subject to the license * terms in the LICENSE file found in the top-level directory of this * distribution and at http://akaros.cs.berkeley.edu/files/Plan9License. No * part of the UCB release of Plan 9, including this file, may be copied, * modified, propagated, or distributed except according to the terms contained * in the LICENSE file. */ #include <u.h>#include <libc.h> #define	TEMP	"/n/temp" voidusage(void){	fprint(2, "usage: pipefile [-d] [-r command] [-w command] file\n");	exits("usage");} voidconnect(char *cmd, int fd0, int fd1){	switch(rfork(RFPROC|RFFDG|RFREND|RFNOWAIT)){	case -1:		sysfatal("fork %s: %r", cmd);		break;	default:		close(fd0);		close(fd1);		return;	case 0:		dup(fd0, 0);		dup(fd1, 1);		close(fd0);		close(fd1);		execl("/bin/rc", "rc", "-c", cmd, nil);		sysfatal("exec %s: %r", cmd);		break;	}} voidmain(int argc, char *argv[]){	char *file;	char *rcmd, *wcmd;	int fd0, fd1, ifd0, ifd1, dupflag; 	rfork(RFNOTEG);	dupflag = 0;	rcmd = wcmd = nil;	ARGBEGIN{	case 'd':		dupflag = 1;		break;	case 'r':		rcmd = EARGF(usage());		break;	case 'w':		wcmd = EARGF(usage());		break;	default:		usage();	}ARGEND 	if(argc!=1 || (rcmd==nil && wcmd==nil))		usage();	if(rcmd == nil)		rcmd = "/bin/cat";	if(wcmd == nil)		wcmd = "/bin/cat"; 	file = argv[0];	if(dupflag){		ifd0 = open(file, ORDWR);		if(ifd0 < 0)			sysfatal("open %s: %r", file);		ifd1 = dup(ifd0, -1);	}else{		ifd0 = open(file, OREAD);		if(ifd0 < 0)			sysfatal("open %s: %r", file);		ifd1 = open(file, OWRITE);		if(ifd1 < 0)			sysfatal("open %s: %r", file);	} 	if(bind("#|", TEMP, MREPL) < 0)		sysfatal("bind pipe %s: %r", TEMP);	if(bind(TEMP "/data", file, MREPL) < 0)		sysfatal("bind %s %s: %r", TEMP "/data", file); 	fd0 = open(TEMP "/data1", OREAD);	if(fd0 < 0)		sysfatal("open %s: %r", TEMP "/data1");	connect(wcmd, fd0, ifd1);	fd1 = open(TEMP "/data1", OWRITE);	if(fd1 < 0)		sysfatal("open %s: %r", TEMP "/data1");	connect(rcmd, ifd0, fd1);	unmount(nil, TEMP);	exits(nil);}