msh.c

来自「手机嵌入式Linux下可用的busybox源码」· C语言 代码 · 共 3,606 行 · 第 1/5 页

		fail();
	scraphere();
	freehere(1);
	runtrap(0);
	_exit(exstat);
	/* NOTREACHED */
}

void warn(s)
register char *s;
{
	if (*s) {
		prs(s);
		exstat = -1;
	}
	prs("\n");
	if (flag['e'])
		leave();
}

void err(s)
char *s;
{
	warn(s);
	if (flag['n'])
		return;
	if (!interactive)
		leave();
	if (e.errpt)
		longjmp(e.errpt, 1);
	closeall();
	e.iop = e.iobase = iostack;
}

int newenv(f)
int f;
{
	register struct env *ep;

	if (f) {
		quitenv();
		return (1);
	}
	ep = (struct env *) space(sizeof(*ep));
	if (ep == NULL) {
		while (e.oenv)
			quitenv();
		fail();
	}
	*ep = e;
	e.oenv = ep;
	e.errpt = errpt;
	return (0);
}

void quitenv()
{
	register struct env *ep;
	int fd;

	if ((ep = e.oenv) != NULL) {
		fd = e.iofd;
		e = *ep;
		/* should close `'d files */
		freecell(ep);
		while (--fd >= e.iofd)
			close(fd);
	}
}

/*
 * Is any character from s1 in s2?
 */
int anys(s1, s2)
register char *s1, *s2;
{
	while (*s1)
		if (any(*s1++, s2))
			return (1);
	return (0);
}

/*
 * Is character c in s?
 */
int any(c, s)
register int c;
register char *s;
{
	while (*s)
		if (*s++ == c)
			return (1);
	return (0);
}

char *putn(n)
register int n;
{
	return (itoa(n, -1));
}

char *itoa(u, n)
register unsigned u;
int n;
{
	register char *cp;
	static char s[20];
	int m;

	m = 0;
	if (n < 0 && (int) u < 0) {
		m++;
		u = -u;
	}
	cp = s + sizeof(s);
	*--cp = 0;
	do {
		*--cp = u % 10 + '0';
		u /= 10;
	} while (--n > 0 || u);
	if (m)
		*--cp = '-';
	return (cp);
}

void next(f)
int f;
{
	PUSHIO(afile, f, filechar);
}

void onintr(s)
int s;							/* ANSI C requires a parameter */
{
	signal(SIGINT, onintr);
	intr = 1;
	if (interactive) {
		if (inparse) {
			prs("\n");
			fail();
		}
	} else if (heedint) {
		execflg = 0;
		leave();
	}
}

int letter(c)
int c;
{
	return ((c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') || c == '_');
}

int digit(c)
int c;
{
	return (c >= '0' && c <= '9');
}

int letnum(c)
int c;
{
	return (letter(c) || digit(c));
}

char *space(n)
int n;
{
	register char *cp;

	if ((cp = getcell(n)) == 0)
		err("out of string space");
	return (cp);
}

char *strsave(s, a)
register char *s;
int a;
{
	register char *cp, *xp;

	if ((cp = space(strlen(s) + 1)) != NULL) {
		setarea((char *) cp, a);
		for (xp = cp; (*xp++ = *s++) != '\0';);
		return (cp);
	}
	return ("");
}

/*
 * trap handling
 */
void sig(i)
register int i;
{
	trapset = i;
	signal(i, sig);
}

void runtrap(i)
int i;
{
	char *trapstr;

	if ((trapstr = trap[i]) == NULL)
		return;
	if (i == 0)
		trap[i] = 0;
	RUN(aword, trapstr, nlchar);
}

/* -------- var.c -------- */

/*
 * Find the given name in the dictionary
 * and return its value.  If the name was
 * not previously there, enter it now and
 * return a null value.
 */
struct var *lookup(n)
register char *n;
{
	register struct var *vp;
	register char *cp;
	register int c;
	static struct var dummy;

	if (digit(*n)) {
		dummy.name = n;
		for (c = 0; digit(*n) && c < 1000; n++)
			c = c * 10 + *n - '0';
		dummy.status = RONLY;
		dummy.value = c <= dolc ? dolv[c] : null;
		return (&dummy);
	}
	for (vp = vlist; vp; vp = vp->next)
		if (eqname(vp->name, n))
			return (vp);
	cp = findeq(n);
	vp = (struct var *) space(sizeof(*vp));
	if (vp == 0 || (vp->name = space((int) (cp - n) + 2)) == 0) {
		dummy.name = dummy.value = "";
		return (&dummy);
	}
	for (cp = vp->name; (*cp = *n++) && *cp != '='; cp++);
	if (*cp == 0)
		*cp = '=';
	*++cp = 0;
	setarea((char *) vp, 0);
	setarea((char *) vp->name, 0);
	vp->value = null;
	vp->next = vlist;
	vp->status = GETCELL;
	vlist = vp;
	return (vp);
}

/*
 * give variable at `vp' the value `val'.
 */
void setval(vp, val)
struct var *vp;
char *val;
{
	nameval(vp, val, (char *) NULL);
}

/*
 * if name is not NULL, it must be
 * a prefix of the space `val',
 * and end with `='.
 * this is all so that exporting
 * values is reasonably painless.
 */
void nameval(vp, val, name)
register struct var *vp;
char *val, *name;
{
	register char *cp, *xp;
	char *nv;
	int fl;

	if (vp->status & RONLY) {
		for (xp = vp->name; *xp && *xp != '=';)
			put1c(*xp++);
		err(" is read-only");
		return;
	}
	fl = 0;
	if (name == NULL) {
		xp = space(strlen(vp->name) + strlen(val) + 2);
		if (xp == 0)
			return;
		/* make string:  name=value */
		setarea((char *) xp, 0);
		name = xp;
		for (cp = vp->name; (*xp = *cp++) && *xp != '='; xp++);
		if (*xp++ == 0)
			xp[-1] = '=';
		nv = xp;
		for (cp = val; (*xp++ = *cp++) != '\0';);
		val = nv;
		fl = GETCELL;
	}
	if (vp->status & GETCELL)
		freecell(vp->name);		/* form new string `name=value' */
	vp->name = name;
	vp->value = val;
	vp->status |= fl;
}

void export(vp)
struct var *vp;
{
	vp->status |= EXPORT;
}

void ronly(vp)
struct var *vp;
{
	if (letter(vp->name[0]))	/* not an internal symbol ($# etc) */
		vp->status |= RONLY;
}

int isassign(s)
register char *s;
{
	if (!letter((int) *s))
		return (0);
	for (; *s != '='; s++)
		if (*s == 0 || !letnum(*s))
			return (0);
	return (1);
}

int assign(s, cf)
register char *s;
int cf;
{
	register char *cp;
	struct var *vp;

	if (!letter(*s))
		return (0);
	for (cp = s; *cp != '='; cp++)
		if (*cp == 0 || !letnum(*cp))
			return (0);
	vp = lookup(s);
	nameval(vp, ++cp, cf == COPYV ? (char *) NULL : s);
	if (cf != COPYV)
		vp->status &= ~GETCELL;
	return (1);
}

int checkname(cp)
register char *cp;
{
	if (!letter(*cp++))
		return (0);
	while (*cp)
		if (!letnum(*cp++))
			return (0);
	return (1);
}

void putvlist(f, out)
register int f, out;
{
	register struct var *vp;

	for (vp = vlist; vp; vp = vp->next)
		if (vp->status & f && letter(*vp->name)) {
			if (vp->status & EXPORT)
				write(out, "export ", 7);
			if (vp->status & RONLY)
				write(out, "readonly ", 9);
			write(out, vp->name, (int) (findeq(vp->name) - vp->name));
			write(out, "\n", 1);
		}
}

int eqname(n1, n2)
register char *n1, *n2;
{
	for (; *n1 != '=' && *n1 != 0; n1++)
		if (*n2++ != *n1)
			return (0);
	return (*n2 == 0 || *n2 == '=');
}

static char *findeq(cp)
register char *cp;
{
	while (*cp != '\0' && *cp != '=')
		cp++;
	return (cp);
}

/* -------- gmatch.c -------- */
/*
 * int gmatch(string, pattern)
 * char *string, *pattern;
 *
 * Match a pattern as in sh(1).
 */

#define CMASK   0377
#define QUOTE   0200
#define QMASK   (CMASK&~QUOTE)
#define NOT     '!'				/* might use ^ */

int gmatch(s, p)
register char *s, *p;
{
	register int sc, pc;

	if (s == NULL || p == NULL)
		return (0);
	while ((pc = *p++ & CMASK) != '\0') {
		sc = *s++ & QMASK;
		switch (pc) {
		case '[':
			if ((p = cclass(p, sc)) == NULL)
				return (0);
			break;

		case '?':
			if (sc == 0)
				return (0);
			break;

		case '*':
			s--;
			do {
				if (*p == '\0' || gmatch(s, p))
					return (1);
			} while (*s++ != '\0');
			return (0);

		default:
			if (sc != (pc & ~QUOTE))
				return (0);
		}
	}
	return (*s == 0);
}

static char *cclass(p, sub)
register char *p;
register int sub;
{
	register int c, d, not, found;

	if ((not = *p == NOT) != 0)
		p++;
	found = not;
	do {
		if (*p == '\0')
			return ((char *) NULL);
		c = *p & CMASK;
		if (p[1] == '-' && p[2] != ']') {
			d = p[2] & CMASK;
			p++;
		} else
			d = c;
		if (c == sub || (c <= sub && sub <= d))
			found = !not;
	} while (*++p != ']');
	return (found ? p + 1 : (char *) NULL);
}

/* -------- area.c -------- */
#define REGSIZE         sizeof(struct region)
#define GROWBY          256
#define FREE 32767
#define BUSY 0
#define ALIGN (sizeof(int)-1)

/* #include "area.h" */

struct region {
	struct region *next;
	int area;
};

/*
 * All memory between (char *)areabot and (char *)(areatop+1) is
 * exclusively administered by the area management routines.
 */
#define sbrk(X) ({ void * __q = (void *)-1; if (brkaddr + (int)(X) < brktop) { __q = brkaddr; brkaddr+=(int)(X); } __q;})

static struct region *areabot;	/* bottom of area */
static struct region *areatop;	/* top of area */
static struct region *areanxt;	/* starting point of scan */

static void *brktop;
static void *brkaddr;

static void initarea()
{
	brkaddr = malloc(65000);
	brktop = brkaddr + 65000;

	while ((int) sbrk(0) & ALIGN)
		sbrk(1);
	areabot = (struct region *) sbrk(REGSIZE);

	areabot->next = areabot;
	areabot->area = BUSY;
	areatop = areabot;
	areanxt = areabot;
}

char *getcell(nbytes)
unsigned nbytes;
{
	int nregio;
	register struct region *p, *q;
	int i;

	if (nbytes == 0)			/* silly and defeats the algorithm */
		Abort();

	/*
	 * round upwards and add administration area
	 */
	nregio = (nbytes + (REGSIZE - 1)) / REGSIZE + 1;
	for (p = areanxt;;) {
		if (p->area > areanum) {
			/*
			 * merge free cells
			 */
			while ((q = p->next)->area > areanum && q != areanxt)
				p->next = q->next;
			/*
			 * exit loop if cell big enough
			 */
			if (q >= p + nregio)
				goto found;
		}
		p = p->next;
		if (p == areanxt)
			break;
	}
	i = nregio >= GROWBY ? nregio : GROWBY;
	p = (struct region *) sbrk(i * REGSIZE);
	if (p == (struct region *) -1)
		return ((char *) NULL);
	p--;
	if (p != areatop)			/* allocated areas are contiguous */
		Abort();

	q = p + i;
	p->next = q;
	p->area = FREE;
	q->next = areabot;
	q->area = BUSY;
	areatop = q;
  found:
	/*
	 * we found a FREE area big enough, pointed to by 'p', and up to 'q'
	 */
	areanxt = p + nregio;
	if (areanxt < q) {
		/*
		 * split into requested area and rest
		 */
		if (areanxt + 1 > q)	/* insufficient space left for admin */
			Abort();

		areanxt->next = q;
		areanxt->area = FREE;
		p->next = areanxt;
	}
	p->area = areanum;
	return ((char *) (p + 1));
}


void freecell(void *cp)
{
	register struct region *p;

	if ((p = (struct region *) cp) != NULL) {
		p--;
		if (p < areanxt)
			areanxt = p;
		p->area = FREE;
	}
}

void freearea(a)
register int a;
{
	register struct region *p, *top;

	top = areatop;
	for (p = areabot; p != top; p = p->next)
		if (p->area >= a)
			p->area = FREE;
}

void setarea(cp, a)
char *cp;
int a;
{
	register struct region *p;

	if ((p = (struct region *) cp) != NULL)
		(p - 1)->area = a;
}

int getarea(cp)
char *cp;
{
	return ((struct region *) cp - 1)->area;
}

void garbage()
{
	register struct region *p, *q, *top;

	top = areatop;
	for (p = areabot; p != top; p = p->next) {
		if (p->area > areanum) {
			while ((q = p->next)->area > areanum)
				p->next = q->next;
			areanxt = p;
		}
	}
}

/* -------- csyn.c -------- */
/*
 * shell: syntax (C version)
 */

typedef union {
	char *cp;
	char **wp;
	int i;
	struct op *o;
} YYSTYPE;

#define WORD    256
#define LOGAND  257
#define LOGOR   258
#define BREAK   259
#define IF      260
#define THEN    261
#define ELSE    262
#define ELIF    263
#define FI      264
#define CASE    265
#define ESAC    266
#define FOR     267
#define WHILE   268
#define UNTIL   269
#define DO      270
#define DONE    271
#define IN      272
#define YYERRCODE 300

/* flags to yylex */
#define CONTIN  01				/* skip new lines to complete command */

#define SYNTAXERR       zzerr()
static int startl;
static int peeksym;
static int nlseen;
static int iounit = IODEFAULT;

static YYSTYPE yylval;

static struct op *pipeline(int cf);
static struct op *andor(void);
static struct op *c_list(void);
static int synio(int cf);
static void musthave(int c, int cf);
static struct op *simple(void);
static struct op *nested(int type, int mark);
static struct op *command(int cf);
static struct op *dogroup(int onlydone);
static struct op *thenpart(void);
static struct op *elsepart(void);
static struct op *caselist(void);
static struct op *casepart(void);
static char **pattern(void);
static char **wordlist(void);
static struct op *list(struct op *t1, struct op *t2);
static struct op *block(int type, struct op *t1, struct op *t2, char **wp);
static struct op *newtp(void);
static struct op *namelist(struct op *t);
static char **copyw(void);
static void word(char *cp);
static struct ioword **copyio(void);
static struct ioword *io(int u, int f, char *cp);
static void zzerr(void);
static void yyerror(char *s);
static int yylex(int cf);
static int collect(int c, int c1);
static int dual(int c);
static void diag(int ec);
static char *tree(unsigned size);

int yyparse()
{
	startl = 1;
	peeksym = 0;
	yynerrs = 0;
	outtree = c_list();
	musthave('\n', 0);
	return (yynerrs != 0);
}

static struct op *pipeline(cf)
int cf;
{
	register struct op *t, *p;
	register int c;

	t = command(cf);