#/* * UNIX shell * * S. R. Bourne * Bell Telephone Laboratories * */#include	"defs.h"PROC STRING *copyargs();LOCAL DOLPTR	dolh;CHAR	flagadr[10];CHAR	flagchar[] = {	'x',	'n',	'v',	't',	's',	'i',	'e',	'r',	'k',	'u',	0};INT	flagval[]  = {	execpr,	noexec,	readpr,	oneflg,	stdflg,	intflg,	errflg,	rshflg,	keyflg,	setflg,	0};/* ========	option handling	======== */INT	options(argc,argv)	STRING		*argv;	INT		argc;{	REG STRING	cp;	REG STRING	*argp=argv;	REG STRING	flagc;	STRING		flagp;	IF argc>1 ANDF *argp[1]=='-'	THEN	cp=argp[1];		flags &= ~(execpr|readpr);		WHILE *++cp		DO	flagc=flagchar;			WHILE *flagc ANDF *flagc != *cp DO flagc++ OD			IF *cp == *flagc			THEN	flags |= flagval[flagc-flagchar];			ELIF *cp=='c' ANDF argc>2 ANDF comdiv==0			THEN	comdiv=argp[2];				argp[1]=argp[0]; argp++; argc--;			ELSE	failed(argv[1],badopt);			FI		OD		argp[1]=argp[0]; argc--;	FI	/* set up $- */	flagc=flagchar;	flagp=flagadr;	WHILE *flagc	DO IF flags&flagval[flagc-flagchar]	   THEN *flagp++ = *flagc;	   FI	   flagc++;	OD	*flagp++=0;	return(argc);}VOID	setargs(argi)	STRING		argi[];{	/* count args */	REG STRING	*argp=argi;	REG INT		argn=0;	WHILE Rcheat(*argp++)!=ENDARGS DO argn++ OD	/* free old ones unless on for loop chain */	freeargs(dolh);	dolh=copyargs(argi,argn);	/* sets dolv */	assnum(&dolladr,dolc=argn-1);}freeargs(blk)	DOLPTR		blk;{	REG STRING	*argp;	REG DOLPTR	argr=0;	REG DOLPTR	argblk;	IF argblk=blk	THEN	argr = argblk->dolnxt;		IF (--argblk->doluse)==0		THEN	FOR argp=argblk->dolarg; Rcheat(*argp)!=ENDARGS; argp++			DO free(*argp) OD			free(argblk);		FI	FI	return(argr);}LOCAL STRING *	copyargs(from, n)	STRING		from[];{	REG STRING *	np=alloc(sizeof(STRING*)*n+3*BYTESPERWORD);	REG STRING *	fp=from;	REG STRING *	pp=np;	np->doluse=1;	/* use count */	np=np->dolarg;	dolv=np;	WHILE n--	DO *np++ = make(*fp++) OD	*np++ = ENDARGS;	return(pp);}clearup(){	/* force `for' $* lists to go away */	WHILE argfor=freeargs(argfor) DONE	/* clean up io files */	WHILE pop() DONE}DOLPTR	useargs(){	IF dolh	THEN	dolh->doluse++;		dolh->dolnxt=argfor;		return(argfor=dolh);	ELSE	return(0);	FI}