run.c

早期freebsd实现

	x->fval = n;
	return(x);
}

Cell *condexpr(Node **a, int n)	/* a[0] ? a[1] : a[2] */
{
	register Cell *x;

	x = execute(a[0]);
	if (istrue(x)) {
		tempfree(x);
		x = execute(a[1]);
	} else {
		tempfree(x);
		x = execute(a[2]);
	}
	return(x);
}

Cell *ifstat(Node **a, int n)	/* if (a[0]) a[1]; else a[2] */
{
	register Cell *x;

	x = execute(a[0]);
	if (istrue(x)) {
		tempfree(x);
		x = execute(a[1]);
	} else if (a[2] != 0) {
		tempfree(x);
		x = execute(a[2]);
	}
	return(x);
}

Cell *whilestat(Node **a, int n)	/* while (a[0]) a[1] */
{
	register Cell *x;

	for (;;) {
		x = execute(a[0]);
		if (!istrue(x))
			return(x);
		tempfree(x);
		x = execute(a[1]);
		if (isbreak(x)) {
			x = true;
			return(x);
		}
		if (isnext(x) || isexit(x) || isret(x))
			return(x);
		tempfree(x);
	}
}

Cell *dostat(Node **a, int n)	/* do a[0]; while(a[1]) */
{
	register Cell *x;

	for (;;) {
		x = execute(a[0]);
		if (isbreak(x))
			return true;
		if (isnext(x) || isexit(x) || isret(x))
			return(x);
		tempfree(x);
		x = execute(a[1]);
		if (!istrue(x))
			return(x);
		tempfree(x);
	}
}

Cell *forstat(Node **a, int n)	/* for (a[0]; a[1]; a[2]) a[3] */
{
	register Cell *x;

	x = execute(a[0]);
	tempfree(x);
	for (;;) {
		if (a[1]!=0) {
			x = execute(a[1]);
			if (!istrue(x)) return(x);
			else tempfree(x);
		}
		x = execute(a[3]);
		if (isbreak(x))		/* turn off break */
			return true;
		if (isnext(x) || isexit(x) || isret(x))
			return(x);
		tempfree(x);
		x = execute(a[2]);
		tempfree(x);
	}
}

Cell *instat(Node **a, int n)	/* for (a[0] in a[1]) a[2] */
{
	register Cell *x, *vp, *arrayp, *cp, *ncp;
	Array *tp;
	int i;

	vp = execute(a[0]);
	arrayp = execute(a[1]);
	if (!isarr(arrayp)) {
		return true;
	}
	tp = (Array *) arrayp->sval;
	tempfree(arrayp);
	for (i = 0; i < tp->size; i++) {	/* this routine knows too much */
		for (cp = tp->tab[i]; cp != NULL; cp = ncp) {
			setsval(vp, cp->nval);
			ncp = cp->cnext;
			x = execute(a[2]);
			if (isbreak(x)) {
				tempfree(vp);
				return true;
			}
			if (isnext(x) || isexit(x) || isret(x)) {
				tempfree(vp);
				return(x);
			}
			tempfree(x);
		}
	}
	return true;
}

/* if someone ever wants to run over the arrays in sorted order, */
/* here it is.  but it will likely run slower, not faster. */

/*
 *int qstrcmp(p, q)
 *	uchar **p, **q;
 *{
 *	return strcmp(*p, *q);
 *}
 */

/*Cell *instat(Node **a, int n)	/* for (a[0] in a[1]) a[2] */
/*{
/*	register Cell *x, *vp, *arrayp, *cp, *ncp, *ret;
/*	Array *tp;
/*	int i, ne;
/*#define BIGENOUGH 1000
/*	uchar *elems[BIGENOUGH], **ep;
/*
/*	vp = execute(a[0]);
/*	arrayp = execute(a[1]);
/*	if (!isarr(arrayp))
/*		ERROR "%s is not an array", arrayp->nval FATAL;
/*	tp = (Array *) arrayp->sval;
/*	tempfree(arrayp);
/*	ep = elems;
/*	ret = true;
/*	if (tp->nelem >= BIGENOUGH)
/*		ep = (uchar **) malloc(tp->nelem * sizeof(char *));
/*
/*	for (i = ne = 0; i < tp->size; i++)
/*		for (cp = tp->tab[i]; cp != NULL; cp = cp->cnext)
/*			ep[ne++] = cp->nval;
/*	if (ne != tp->nelem)
/*		ERROR "can't happen: lost elems %d vs. %d", ne, tp->nelem FATAL;
/*	qsort(ep, ne, sizeof(char *), qstrcmp);
/*	for (i = 0; i < ne; i++) {
/*		setsval(vp, ep[i]);
/*		x = execute(a[2]);
/*		if (isbreak(x)) {
/*			tempfree(vp);
/*			break;
/*		}
/*		if (isnext(x) || isexit(x) || isret(x)) {
/*			tempfree(vp);
/*			ret = x;
/*			break;
/*		}
/*		tempfree(x);
/*	}
/*	if (ep != elems)
/*		free(ep);
/*	return ret;
/*}
*/


Cell *bltin(Node **a, int n)	/* builtin functions. a[0] is type, a[1] is arg list */
{
	register Cell *x, *y;
	Awkfloat u;
	register int t;
	uchar *p, buf[RECSIZE];
	Node *nextarg;
	FILE *fp;

	t = (int) a[0];
	x = execute(a[1]);
	nextarg = a[1]->nnext;
	switch (t) {
	case FLENGTH:
		u = strlen(getsval(x)); break;
	case FLOG:
		u = errcheck(log(getfval(x)), "log"); break;
	case FINT:
		modf(getfval(x), &u); break;
	case FEXP:
		u = errcheck(exp(getfval(x)), "exp"); break;
	case FSQRT:
		u = errcheck(sqrt(getfval(x)), "sqrt"); break;
	case FSIN:
		u = sin(getfval(x)); break;
	case FCOS:
		u = cos(getfval(x)); break;
	case FATAN:
		if (nextarg == 0) {
			ERROR "atan2 requires two arguments; returning 1.0" WARNING;
			u = 1.0;
		} else {
			y = execute(a[1]->nnext);
			u = atan2(getfval(x), getfval(y));
			tempfree(y);
			nextarg = nextarg->nnext;
		}
		break;
	case FSYSTEM:
		fflush(stdout);		/* in case something is buffered already */
		u = (Awkfloat) system((char *)getsval(x)) / 256;   /* 256 is unix-dep */
		break;
	case FRAND:
		/* in principle, rand() returns something in 0..RAND_MAX */
		u = (Awkfloat) (rand() % RAND_MAX) / RAND_MAX;
		break;
	case FSRAND:
		if (x->tval & REC)	/* no argument provided */
			u = time((long *)0);
		else
			u = getfval(x);
		srand((int) u); u = (int) u;
		break;
	case FTOUPPER:
	case FTOLOWER:
		strcpy(buf, getsval(x));
		if (t == FTOUPPER) {
			for (p = buf; *p; p++)
				if (islower(*p))
					*p = toupper(*p);
		} else {
			for (p = buf; *p; p++)
				if (isupper(*p))
					*p = tolower(*p);
		}
		tempfree(x);
		x = gettemp();
		setsval(x, buf);
		return x;
	case FFLUSH:
		if ((fp = openfile(GT, getsval(x))) == NULL)
			u = EOF;
		else
			u = fflush(fp);
		break;
	default:	/* can't happen */
		ERROR "illegal function type %d", t FATAL;
		break;
	}
	tempfree(x);
	x = gettemp();
	setfval(x, u);
	if (nextarg != 0) {
		ERROR "warning: function has too many arguments" WARNING;
		for ( ; nextarg; nextarg = nextarg->nnext)
			execute(nextarg);
	}
	return(x);
}

Cell *printstat(Node **a, int n)	/* print a[0] */
{
	register Node *x;
	register Cell *y;
	FILE *fp;

	if (a[1] == 0)	/* a[1] is redirection operator, a[2] is file */
		fp = stdout;
	else
		fp = redirect((int)a[1], a[2]);
	for (x = a[0]; x != NULL; x = x->nnext) {
		y = execute(x);
		fputs((char *)getsval(y), fp);
		tempfree(y);
		if (x->nnext == NULL)
			fputs((char *)*ORS, fp);
		else
			fputs((char *)*OFS, fp);
	}
	if (a[1] != 0)
		fflush(fp);
	if (ferror(fp))
		ERROR "write error on %s", filename(fp) FATAL;
	return(true);
}

Cell *nullproc(Node **a, int n)
{
	n;
	a;
	return 0;
}


FILE *redirect(int a, Node *b)	/* set up all i/o redirections */
{
	FILE *fp;
	Cell *x;
	uchar *fname;

	x = execute(b);
	fname = getsval(x);
	fp = openfile(a, fname);
	if (fp == NULL)
		ERROR "can't open file %s", fname FATAL;
	tempfree(x);
	return fp;
}

struct files {
	FILE	*fp;
	uchar	*fname;
	int	mode;	/* '|', 'a', 'w' => LE/LT, GT */
} files[FOPEN_MAX] ={
	{ stdin,  "/dev/stdin",  LT },	/* watch out: don't free this! */
	{ stdout, "/dev/stdout", GT },
	{ stderr, "/dev/stderr", GT }
};

FILE *openfile(int a, uchar *us)
{
	char *s = us;
	register int i, m;
	register FILE *fp;

	if (*s == '\0')
		ERROR "null file name in print or getline" FATAL;
	for (i=0; i < FOPEN_MAX; i++)
		if (files[i].fname && strcmp(s, files[i].fname) == 0)
			if (a == files[i].mode || a==APPEND && files[i].mode==GT)
				return files[i].fp;
	for (i=0; i < FOPEN_MAX; i++)
		if (files[i].fp == 0)
			break;
	if (i >= FOPEN_MAX)
		ERROR "%s makes too many open files", s FATAL;
	fflush(stdout);	/* force a semblance of order */
	m = a;
	if (a == GT) {
		fp = fopen(s, "w");
	} else if (a == APPEND) {
		fp = fopen(s, "a");
		m = GT;	/* so can mix > and >> */
	} else if (a == '|') {	/* output pipe */
		fp = popen(s, "w");
	} else if (a == LE) {	/* input pipe */
		fp = popen(s, "r");
	} else if (a == LT) {	/* getline <file */
		fp = strcmp(s, "-") == 0 ? stdin : fopen(s, "r");	/* "-" is stdin */
	} else	/* can't happen */
		ERROR "illegal redirection %d", a FATAL;
	if (fp != NULL) {
		files[i].fname = tostring(s);
		files[i].fp = fp;
		files[i].mode = m;
	}
	return fp;
}

uchar *filename(FILE *fp)
{
	int i;

	for (i = 0; i < FOPEN_MAX; i++)
		if (fp == files[i].fp)
			return files[i].fname;
	return "???";
}

Cell *closefile(Node **a, int n)
{
	register Cell *x;
	int i, stat;

	n;
	x = execute(a[0]);
	getsval(x);
	for (i = 0; i < FOPEN_MAX; i++)
		if (files[i].fname && strcmp(x->sval, files[i].fname) == 0) {
			if (ferror(files[i].fp))
				ERROR "i/o error occurred on %s", files[i].fname WARNING;
			if (files[i].mode == '|' || files[i].mode == LE)
				stat = pclose(files[i].fp);
			else
				stat = fclose(files[i].fp);
			if (stat == EOF)
				ERROR "i/o error occurred closing %s", files[i].fname WARNING;
			if (i > 2)	/* don't do /dev/std... */
				xfree(files[i].fname);
			files[i].fname = NULL;	/* watch out for ref thru this */
			files[i].fp = NULL;
		}
	tempfree(x);
	return(true);
}

void closeall(void)
{
	int i, stat;

	for (i = 0; i < FOPEN_MAX; i++)
		if (files[i].fp) {
			if (ferror(files[i].fp))
				ERROR "i/o error occurred on %s", files[i].fname WARNING;
			if (files[i].mode == '|' || files[i].mode == LE)
				stat = pclose(files[i].fp);
			else
				stat = fclose(files[i].fp);
			if (stat == EOF)
				ERROR "i/o error occurred while closing %s", files[i].fname WARNING;
		}
}

#define	SUBSIZE	(20 * RECSIZE)

Cell *sub(Node **a, int nnn)	/* substitute command */
{
	register uchar *sptr, *pb, *q;
	register Cell *x, *y, *result;
	uchar buf[SUBSIZE], *t;
	fa *pfa;

	x = execute(a[3]);	/* target string */
	t = getsval(x);
	if (a[0] == 0)		/* 0 => a[1] is already-compiled regexpr */
		pfa = (fa *) a[1];	/* regular expression */
	else {
		y = execute(a[1]);
		pfa = makedfa(getsval(y), 1);
		tempfree(y);
	}
	y = execute(a[2]);	/* replacement string */
	result = false;
	if (pmatch(pfa, t)) {
		pb = buf;
		sptr = t;
		while (sptr < patbeg)
			*pb++ = *sptr++;
		sptr = getsval(y);
		while (*sptr != 0 && pb < buf + SUBSIZE - 1)
			if (*sptr == '\\' && *(sptr+1) == '&') {
				sptr++;		/* skip \, */
				*pb++ = *sptr++; /* add & */
			} else if (*sptr == '&') {
				sptr++;
				for (q = patbeg; q < patbeg+patlen; )
					*pb++ = *q++;
			} else
				*pb++ = *sptr++;
		*pb = '\0';
		if (pb >= buf + SUBSIZE)
			ERROR "sub() result %30s too big", buf FATAL;
		sptr = patbeg + patlen;
		if ((patlen == 0 && *patbeg) || (patlen && *(sptr-1)))
			while (*pb++ = *sptr++)
				;
		if (pb >= buf + SUBSIZE)
			ERROR "sub() result %.30s too big", buf FATAL;
		setsval(x, buf);
		result = true;;
	}
	tempfree(x);
	tempfree(y);
	return result;
}

Cell *gsub(Node **a, int nnn)	/* global substitute */
{
	register Cell *x, *y;
	register uchar *rptr, *sptr, *t, *pb;
	uchar buf[SUBSIZE];
	register fa *pfa;
	int mflag, tempstat, num;

	mflag = 0;	/* if mflag == 0, can replace empty string */
	num = 0;
	x = execute(a[3]);	/* target string */
	t = getsval(x);
	if (a[0] == 0)		/* 0 => a[1] is already-compiled regexpr */
		pfa = (fa *) a[1];	/* regular expression */
	else {
		y = execute(a[1]);
		pfa = makedfa(getsval(y), 1);
		tempfree(y);
	}
	y = execute(a[2]);	/* replacement string */
	if (pmatch(pfa, t)) {
		tempstat = pfa->initstat;
		pfa->initstat = 2;
		pb = buf;
		rptr = getsval(y);
		do {
			/*
			uchar *p;
			int i;
			printf("target string: %s, *patbeg = %o, patlen = %d\n",
				t, *patbeg, patlen);
			printf("	match found: ");
			p=patbeg;
			for (i=0; i<patlen; i++)
				printf("%c", *p++);
			printf("\n");
			*/
			if (patlen == 0 && *patbeg != 0) {	/* matched empty string */
				if (mflag == 0) {	/* can replace empty */
					num++;
					sptr = rptr;
					while (*sptr != 0 && pb < buf + SUBSIZE-1)
						if (*sptr == '\\' && *(sptr+1) == '&') {
							sptr++;
							*pb++ = *sptr++;
						} else if (*sptr == '&') {
							uchar *q;
							sptr++;
							for (q = patbeg; q < patbeg+patlen; )
								*pb++ = *q++;
						} else
							*pb++ = *sptr++;
				}
				if (*t == 0)	/* at end */
					goto done;
				*pb++ = *t++;
				if (pb >= buf + SUBSIZE-1)
					ERROR "gsub() result %.30s too big", buf FATAL;
				mflag = 0;
			}
			else {	/* matched nonempty string */
				num++;
				sptr = t;
				while (sptr < patbeg && pb < buf + SUBSIZE-1)
					*pb++ = *sptr++;
				sptr = rptr;
				while (*sptr != 0 && pb < buf + SUBSIZE-1)
					if (*sptr == '\\' && *(sptr+1) == '&') {
						sptr++;
						*pb++ = *sptr++;
					} else if (*sptr == '&') {
						uchar *q;
						sptr++;
						for (q = patbeg; q < patbeg+patlen; )
							*pb++ = *q++;
					} else
						*pb++ = *sptr++;
				t = patbeg + patlen;
				if ((*(t-1) == 0) || (*t == 0))
					goto done;
				if (pb >= buf + SUBSIZE-1)
					ERROR "gsub() result %.30s too big", buf FATAL;
				mflag = 1;
			}
		} while (pmatch(pfa,t));
		sptr = t;
		while (*pb++ = *sptr++)
			;
	done:	if (pb >= buf + SUBSIZE-1)
			ERROR "gsub() result %.30s too big", buf FATAL;
		*pb = '\0';
		setsval(x, buf);
		pfa->initstat = tempstat;
	}
	tempfree(x);
	tempfree(y);
	x = gettemp();
	x->tval = NUM;
	x->fval = num;
	return(x);
}