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

	dolv[n] = dolv[0];
	dolv += n;
	dolc -= n;
	setval(lookup("#"), putn(dolc));
	return (0);
}

/*
 * execute login and newgrp directly
 */
int dologin(t)
struct op *t;
{
	register char *cp;

	if (interactive) {
		signal(SIGINT, SIG_DFL);
		signal(SIGQUIT, SIG_DFL);
	}
	cp = rexecve(t->words[0], t->words, makenv(0));
	prs(t->words[0]);
	prs(": ");
	err(cp);
	return (1);
}

int doumask(t)
register struct op *t;
{
	register int i, n;
	register char *cp;

	if ((cp = t->words[1]) == NULL) {
		i = umask(0);
		umask(i);
		for (n = 3 * 4; (n -= 3) >= 0;)
			put1c('0' + ((i >> n) & 07));
		put1c('\n');
	} else {
		for (n = 0; *cp >= '0' && *cp <= '9'; cp++)
			n = n * 8 + (*cp - '0');
		umask(n);
	}
	return (0);
}

int doexec(t)
register struct op *t;
{
	int i;
	jmp_buf ex;
	xint *ofail;

	t->ioact = NULL;
	for (i = 0; (t->words[i] = t->words[i + 1]) != NULL; i++);
	if (i == 0)
		return (1);
	execflg = 1;
	ofail = failpt;
	if (setjmp(failpt = ex) == 0)
		execute(t, NOPIPE, NOPIPE, FEXEC);
	failpt = ofail;
	execflg = 0;
	return (1);
}

int dodot(t)
struct op *t;
{
	int i;
	register char *sp, *tp;
	char *cp;

	if ((cp = t->words[1]) == NULL)
		return (0);
	sp = any('/', cp) ? ":" : path->value;
	while (*sp) {
		tp = e.linep;
		while (*sp && (*tp = *sp++) != ':')
			tp++;
		if (tp != e.linep)
			*tp++ = '/';
		for (i = 0; (*tp++ = cp[i++]) != '\0';);
		if ((i = open(e.linep, 0)) >= 0) {
			exstat = 0;
			next(remap(i));
			return (exstat);
		}
	}
	prs(cp);
	err(": not found");
	return (-1);
}

int dowait(t)
struct op *t;
{
	int i;
	register char *cp;

	if ((cp = t->words[1]) != NULL) {
		i = getn(cp);
		if (i == 0)
			return (0);
	} else
		i = -1;
	setstatus(waitfor(i, 1));
	return (0);
}

int doread(t)
struct op *t;
{
	register char *cp, **wp;
	int nb = 0;
	register int nl = 0;

	if (t->words[1] == NULL) {
		err("Usage: read name ...");
		return (1);
	}
	for (wp = t->words + 1; *wp; wp++) {
		for (cp = e.linep; !nl && cp < elinep - 1; cp++)
			if ((nb = read(0, cp, sizeof(*cp))) != sizeof(*cp) ||
				(nl = (*cp == '\n')) || (wp[1] && any(*cp, ifs->value)))
				break;
		*cp = 0;
		if (nb <= 0)
			break;
		setval(lookup(*wp), e.linep);
	}
	return (nb <= 0);
}

int doeval(t)
register struct op *t;
{
	return (RUN(awordlist, t->words + 1, wdchar));
}

int dotrap(t)
register struct op *t;
{
	register int n, i;
	register int resetsig;

	if (t->words[1] == NULL) {
		for (i = 0; i <= _NSIG; i++)
			if (trap[i]) {
				prn(i);
				prs(": ");
				prs(trap[i]);
				prs("\n");
			}
		return (0);
	}
	resetsig = digit(*t->words[1]);
	for (i = resetsig ? 1 : 2; t->words[i] != NULL; ++i) {
		n = getsig(t->words[i]);
		freecell(trap[n]);
		trap[n] = 0;
		if (!resetsig) {
			if (*t->words[1] != '\0') {
				trap[n] = strsave(t->words[1], 0);
				setsig(n, sig);
			} else
				setsig(n, SIG_IGN);
		} else {
			if (interactive)
				if (n == SIGINT)
					setsig(n, onintr);
				else
					setsig(n, n == SIGQUIT ? SIG_IGN : SIG_DFL);
			else
				setsig(n, SIG_DFL);
		}
	}
	return (0);
}

int getsig(s)
char *s;
{
	register int n;

	if ((n = getn(s)) < 0 || n > _NSIG) {
		err("trap: bad signal number");
		n = 0;
	}
	return (n);
}

void setsig(n, f)
int n;
void (*f) (int);
{
	if (n == 0)
		return;
	if (signal(n, SIG_IGN) != SIG_IGN || ourtrap[n]) {
		ourtrap[n] = 1;
		signal(n, f);
	}
}

int getn(as)
char *as;
{
	register char *s;
	int n, m;

	s = as;
	m = 1;
	if (*s == '-') {
		m = -1;
		s++;
	}
	for (n = 0; digit(*s); s++)
		n = (n * 10) + (*s - '0');
	if (*s) {
		prs(as);
		err(": bad number");
	}
	return (n * m);
}

int dobreak(t)
struct op *t;
{
	return (brkcontin(t->words[1], 1));
}

int docontinue(t)
struct op *t;
{
	return (brkcontin(t->words[1], 0));
}

static int brkcontin(cp, val)
register char *cp;
int val;
{
	register struct brkcon *bc;
	int nl;

	nl = cp == NULL ? 1 : getn(cp);
	if (nl <= 0)
		nl = 999;
	do {
		if ((bc = brklist) == NULL)
			break;
		brklist = bc->nextlev;
	} while (--nl);
	if (nl) {
		err("bad break/continue level");
		return (1);
	}
	isbreak = val;
	longjmp(bc->brkpt, 1);
	/* NOTREACHED */
}

int doexit(t)
struct op *t;
{
	register char *cp;

	execflg = 0;
	if ((cp = t->words[1]) != NULL)
		setstatus(getn(cp));
	leave();
	/* NOTREACHED */
}

int doexport(t)
struct op *t;
{
	rdexp(t->words + 1, export, EXPORT);
	return (0);
}

int doreadonly(t)
struct op *t;
{
	rdexp(t->words + 1, ronly, RONLY);
	return (0);
}

static void rdexp(wp, f, key)
register char **wp;
void (*f) ();
int key;
{
	if (*wp != NULL) {
		for (; *wp != NULL; wp++)
			if (checkname(*wp))
				(*f) (lookup(*wp));
			else
				badid(*wp);
	} else
		putvlist(key, 1);
}

static void badid(s)
register char *s;
{
	prs(s);
	err(": bad identifier");
}

int doset(t)
register struct op *t;
{
	register struct var *vp;
	register char *cp;
	int n;

	if ((cp = t->words[1]) == NULL) {
		for (vp = vlist; vp; vp = vp->next)
			varput(vp->name, 1);
		return (0);
	}
	if (*cp == '-') {
		/* bad: t->words++; */
		for (n = 0; (t->words[n] = t->words[n + 1]) != NULL; n++);
		if (*++cp == 0)
			flag['x'] = flag['v'] = 0;
		else
			for (; *cp; cp++)
				switch (*cp) {
				case 'e':
					if (!interactive)
						flag['e']++;
					break;

				default:
					if (*cp >= 'a' && *cp <= 'z')
						flag[(int) *cp]++;
					break;
				}
		setdash();
	}
	if (t->words[1]) {
		t->words[0] = dolv[0];
		for (n = 1; t->words[n]; n++)
			setarea((char *) t->words[n], 0);
		dolc = n - 1;
		dolv = t->words;
		setval(lookup("#"), putn(dolc));
		setarea((char *) (dolv - 1), 0);
	}
	return (0);
}

void varput(s, out)
register char *s;
int out;
{
	if (letnum(*s)) {
		write(out, s, strlen(s));
		write(out, "\n", 1);
	}
}


#define SECS    60L
#define MINS    3600L

int dotimes()
{
	struct tms tbuf;

	times(&tbuf);

	prn((int) (tbuf.tms_cutime / MINS));
	prs("m");
	prn((int) ((tbuf.tms_cutime % MINS) / SECS));
	prs("s ");
	prn((int) (tbuf.tms_cstime / MINS));
	prs("m");
	prn((int) ((tbuf.tms_cstime % MINS) / SECS));
	prs("s\n");
	return (0);
}

struct builtin {
	char *command;
	int (*fn) ();
};
static struct builtin builtin[] = {
	{":", dolabel},
	{"cd", dochdir},
	{"shift", doshift},
	{"exec", doexec},
	{"wait", dowait},
	{"read", doread},
	{"eval", doeval},
	{"trap", dotrap},
	{"break", dobreak},
	{"continue", docontinue},
	{"exit", doexit},
	{"export", doexport},
	{"readonly", doreadonly},
	{"set", doset},
	{".", dodot},
	{"umask", doumask},
	{"login", dologin},
	{"newgrp", dologin},
	{"times", dotimes},
	{0, 0}
};

int (*inbuilt(s)) ()
register char *s;
{
	register struct builtin *bp;

	for (bp = builtin; bp->command != NULL; bp++)
		if (strcmp(bp->command, s) == 0)
			return (bp->fn);
	return ((int (*)()) NULL);
}


/* -------- eval.c -------- */

/*
 * ${}
 * `command`
 * blank interpretation
 * quoting
 * glob
 */

static int expand(char *cp, struct wdblock **wbp, int f);
static char *blank(int f);
static int dollar(int quoted);
static int grave(int quoted);
static void globname(char *we, char *pp);
static char *generate(char *start1, char *end1, char *middle, char *end);
static int anyspcl(struct wdblock *wb);
static int xstrcmp(char *p1, char *p2);
static void glob0(char *a0, unsigned int a1, int a2,
				  int (*a3) (char *, char *));
static void glob1(char *base, char *lim);
static void glob2(char *i, char *j);
static void glob3(char *i, char *j, char *k);


char **eval(ap, f)
char **ap;
int f;
{
	struct wdblock *wb;
	char **wp;
	char **wf;
	jmp_buf ev;

#if __GNUC__
	/* Avoid longjmp clobbering */
	(void) &wp;
	(void) &ap;
#endif

	wp = NULL;
	wb = NULL;
	wf = NULL;
	if (newenv(setjmp(errpt = ev)) == 0) {
		while (*ap && isassign(*ap))
			expand(*ap++, &wb, f & ~DOGLOB);
		if (flag['k']) {
			for (wf = ap; *wf; wf++) {
				if (isassign(*wf))
					expand(*wf, &wb, f & ~DOGLOB);
			}
		}
		for (wb = addword((char *) 0, wb); *ap; ap++) {
			if (!flag['k'] || !isassign(*ap))
				expand(*ap, &wb, f & ~DOKEY);
		}
		wb = addword((char *) 0, wb);
		wp = getwords(wb);
		quitenv();
	} else
		gflg = 1;
	return (gflg ? (char **) NULL : wp);
}

/*
 * Make the exported environment from the exported
 * names in the dictionary. Keyword assignments
 * will already have been done.
 */
char **makenv(int all)
{
	register struct wdblock *wb;
	register struct var *vp;

	wb = NULL;
	for (vp = vlist; vp; vp = vp->next)
		if (all || vp->status & EXPORT)
			wb = addword(vp->name, wb);
	wb = addword((char *) 0, wb);
	return (getwords(wb));
}

char *evalstr(cp, f)
char *cp;
int f;
{
	struct wdblock *wb;

#if __GNUC__
	/* Avoid longjmp clobbering */
	(void) &cp;
#endif

	wb = NULL;
	if (expand(cp, &wb, f)) {
		if (wb == NULL || wb->w_nword == 0
			|| (cp = wb->w_words[0]) == NULL)
			cp = "";
		freecell(wb);
	} else
		cp = NULL;
	return (cp);
}

static int expand(cp, wbp, f)
char *cp;
register struct wdblock **wbp;
int f;
{
	jmp_buf ev;

#if __GNUC__
	/* Avoid longjmp clobbering */
	(void) &cp;
#endif

	gflg = 0;
	if (cp == NULL)
		return (0);
	if (!anys("$`'\"", cp) &&
		!anys(ifs->value, cp) && ((f & DOGLOB) == 0 || !anys("[*?", cp))) {
		cp = strsave(cp, areanum);
		if (f & DOTRIM)
			unquote(cp);
		*wbp = addword(cp, *wbp);
		return (1);
	}
	if (newenv(setjmp(errpt = ev)) == 0) {
		PUSHIO(aword, cp, strchar);
		e.iobase = e.iop;
		while ((cp = blank(f)) && gflg == 0) {
			e.linep = cp;
			cp = strsave(cp, areanum);
			if ((f & DOGLOB) == 0) {
				if (f & DOTRIM)
					unquote(cp);
				*wbp = addword(cp, *wbp);
			} else
				*wbp = glob(cp, *wbp);
		}
		quitenv();
	} else
		gflg = 1;
	return (gflg == 0);
}

/*
 * Blank interpretation and quoting
 */
static char *blank(f)
int f;
{
	int c, c1;
	register char *sp;
	int scanequals, foundequals;

	sp = e.linep;
	scanequals = f & DOKEY;
	foundequals = 0;

  loop:
	switch (c = subgetc('"', foundequals)) {
	case 0:
		if (sp == e.linep)
			return (0);
		*e.linep++ = 0;
		return (sp);

	default:
		if (f & DOBLANK && any(c, ifs->value))
			goto loop;
		break;

	case '"':
	case '\'':
		scanequals = 0;
		if (INSUB())
			break;
		for (c1 = c; (c = subgetc(c1, 1)) != c1;) {
			if (c == 0)
				break;
			if (c == '\'' || !any(c, "$`\""))
				c |= QUOTE;
			*e.linep++ = c;
		}
		c = 0;
	}
	unget(c);
	if (!letter(c))
		scanequals = 0;
	for (;;) {
		c = subgetc('"', foundequals);
		if (c == 0 ||
			(f & DOBLANK && any(c, ifs->value)) ||
			(!INSUB() && any(c, "\"'"))) {
			scanequals = 0;
			unget(c);
			if (any(c, "\"'"))
				goto loop;
			break;
		}
		if (scanequals) {
			if (c == '=') {
				foundequals = 1;
				scanequals = 0;
			} else if (!letnum(c))
				scanequals = 0;
		}
		*e.linep++ = c;
	}
	*e.linep++ = 0;
	return (sp);
}

/*
 * Get characters, substituting for ` and $
 */
int subgetc(ec, quoted)
register char ec;
int quoted;
{
	register char c;

  again:
	c = getqc(ec);
	if (!INSUB() && ec != '\'') {
		if (c == '`') {
			if (grave(quoted) == 0)
				return (0);
			e.iop->task = XGRAVE;
			goto again;
		}
		if (c == '$' && (c = dollar(quoted)) == 0) {
			e.iop->task = XDOLL;
			goto again;
		}
	}
	return (c);
}

/*
 * Prepare to generate the string returned by ${} substitution.
 */
static int dollar(quoted)
int quoted;
{
	int otask;
	struct io *oiop;
	char *dolp;
	register char *s, c, *cp;
	struct var *vp;

	c = readc();
	s = e.linep;
	if (c != '{') {
		*e.linep++ = c;
		if (letter(c)) {
			while ((c = readc()) != 0 && letnum(c))
				if (e.linep < elinep)
					*e.linep++ = c;
			unget(c);
		}
		c = 0;
	} else {
		oiop = e.iop;
		otask = e.iop->task;
		e.iop->task = XOTHER;
		while ((c = subgetc('"', 0)) != 0 && c != '}' && c != '\n')
			if (e.linep < elinep)
				*e.linep++ = c;
		if (oiop == e.iop)
			e.iop->task = otask;
		if (c != '}') {
			err("unclosed ${");
			gflg++;
			return (c);
		}
	}
	if (e.linep >= elinep) {
		err("string in ${} too long");
		gflg++;
		e.linep -= 10;
	}
	*e.linep = 0;
	if (*s) {
		for (cp = s + 1; *cp; cp++)
			if (any(*cp, "=-+?")) {
				c = *cp;
				*cp++ = 0;
				break;
			}
	} else {
		cp = s;
	}
	if