msh.c

shell-HHARM9200.rar 华恒 AT91rm9200 中Busybox shell的源代码

	if (shell->value == null)
		setval(shell, DEFAULT_SHELL);
	export(shell);

	homedir = lookup("HOME");
	if (homedir->value == null)
		setval(homedir, "/");
	export(homedir);

	setval(lookup("$"), putn(getpid()));

	path = lookup("PATH");
	if (path->value == null) {
		if (geteuid() == 0)
			setval(path, "/sbin:/bin:/usr/sbin:/usr/bin");
		else
			setval(path, "/bin:/usr/bin");
	}
	export(path);

	ifs = lookup("IFS");
	if (ifs->value == null)
		setval(ifs, " \t\n");

	prompt = lookup("PS1");
#ifdef CONFIG_FEATURE_SH_FANCY_PROMPT
	if (prompt->value == null)
#endif
		setval(prompt, "$ ");
	if (geteuid() == 0) {
		setval(prompt, "# ");
		prompt->status &= ~EXPORT;
	}
	cprompt = lookup("PS2");
#ifdef CONFIG_FEATURE_SH_FANCY_PROMPT
	if (cprompt->value == null)
#endif
		setval(cprompt, "> ");

	iof = filechar;
	cflag = 0;
	name = *argv++;
	if (--argc >= 1) {
		if(argv[0][0] == '-' && argv[0][1] != '\0') {
			for (s = argv[0]+1; *s; s++)
				switch (*s) {
				case 'c':
					prompt->status &= ~EXPORT;
					cprompt->status &= ~EXPORT;
					setval(prompt, "");
					setval(cprompt, "");
					cflag = 1;
					if (--argc > 0)
						PUSHIO(aword, *++argv, iof = nlchar);
					break;

				case 'q':
					qflag = SIG_DFL;
					break;

				case 's':
					/* standard input */
					break;

				case 't':
					prompt->status &= ~EXPORT;
					setval(prompt, "");
					iof = linechar;
					break;

				case 'i':
					interactive++;
				default:
					if (*s>='a' && *s<='z')
						flag[(int)*s]++;
				}
		} else {
			argv--;
			argc++;
		}
		if (iof == filechar && --argc > 0) {
			setval(prompt, "");
			setval(cprompt, "");
			prompt->status &= ~EXPORT;
			cprompt->status &= ~EXPORT;
			if (newfile(name = *++argv))
				exit(1);
		}
	}
	setdash();
	if (e.iop < iostack) {
		PUSHIO(afile, 0, iof);
		if (isatty(0) && isatty(1) && !cflag) {
			interactive++;
#ifndef CONFIG_FEATURE_SH_EXTRA_QUIET
			printf( "\n\n" BB_BANNER " Built-in shell (msh)\n");
			printf( "Enter 'help' for a list of built-in commands.\n\n");
#endif
		}
	}
	signal(SIGQUIT, qflag);
	if (name && name[0] == '-') {
		interactive++;
		if ((f = open(".profile", 0)) >= 0)
			next(remap(f));
		if ((f = open("/etc/profile", 0)) >= 0)
			next(remap(f));
	}
	if (interactive)
		signal(SIGTERM, sig);
	if (signal(SIGINT, SIG_IGN) != SIG_IGN)
		signal(SIGINT, onintr);
	dolv = argv;
	dolc = argc;
	dolv[0] = name;
	if (dolc > 1) {
		for (ap = ++argv; --argc > 0;) {
			if (assign(*ap = *argv++, !COPYV)) {
				dolc--;	/* keyword */
			} else {
				ap++;
			}
		}
	}
	setval(lookup("#"), putn((--dolc < 0) ? (dolc = 0) : dolc));

	for (;;) {
		if (interactive && e.iop <= iostack) {
#ifdef CONFIG_FEATURE_COMMAND_EDITING
			current_prompt=prompt->value;
#else
			prs(prompt->value);
#endif
		}
		onecommand();
		/* Ensure that getenv("PATH") stays current */
		setenv("PATH", path->value, 1);
	}
}

static void
setdash()
{
	register char *cp;
	register int c;
	char m['z'-'a'+1];

	cp = m;
	for (c='a'; c<='z'; c++)
		if (flag[(int)c])
			*cp++ = c;
	*cp = 0;
	setval(lookup("-"), m);
}

static int
newfile(s)
register char *s;
{
	register int f;

	if (strcmp(s, "-") != 0) {
		f = open(s, 0);
		if (f < 0) {
			prs(s);
			err(": cannot open");
			return(1);
		}
	} else
		f = 0;
	next(remap(f));
	return(0);
}

static void
onecommand()
{
	register int i;
	jmp_buf m1;

	while (e.oenv)
		quitenv();
	areanum = 1;
	freehere(areanum);
	freearea(areanum);
	garbage();
	wdlist = 0;
	iolist = 0;
	e.errpt = 0;
	e.linep = line;
	yynerrs = 0;
	multiline = 0;
	inparse = 1;
	intr = 0;
	execflg = 0;
	setjmp(failpt = m1);	/* Bruce Evans' fix */
	if (setjmp(failpt = m1) || yyparse() || intr) {
		while (e.oenv)
			quitenv();
		scraphere();
		if (!interactive && intr)
			leave();
		inparse = 0;
		intr = 0;
		return;
	}
	inparse = 0;
	brklist = 0;
	intr = 0;
	execflg = 0;
	if (!flag['n'])
		execute(outtree, NOPIPE, NOPIPE, 0);
	if (!interactive && intr) {
		execflg = 0;
		leave();
	}
	if ((i = trapset) != 0) {
		trapset = 0;
		runtrap(i);
	}
}

static void
fail()
{
	longjmp(failpt, 1);
	/* NOTREACHED */
}

static void
leave()
{
	if (execflg)
		fail();
	scraphere();
	freehere(1);
	runtrap(0);
	exit(exstat);
	/* NOTREACHED */
}

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

static 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;
}

static 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);
}

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

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

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

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

static char *
putn(n)
register int n;
{
	return(itoa(n));
}

static char *
itoa(n)
register int n;
{
	static char s[20];
	snprintf(s, sizeof(s), "%u", n);
	return(s);
}

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

static 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();
	}
}

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

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

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

static 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.
 */
static struct var *
lookup(n)
register char *n;
{
	register struct var *vp;
	register char *cp;
	register int c;
	static struct var dummy;

	if (isdigit(*n)) {
		dummy.name = n;
		for (c = 0; isdigit(*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'.
 */
static 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.
 */
static 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 != '=';)
			putc(*xp++, stderr);
		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;
}

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

static void
ronly(vp)
struct var *vp;
{
	if (isalpha(vp->name[0]) || vp->name[0] == '_')	/* not an internal symbol */
		vp->status |= RONLY;
}

static int
isassign(s)
register char *s;
{
	if (!isalpha((int)*s) && *s != '_')
		return(0);
	for (; *s != '='; s++)
		if (*s == 0 || (!isalnum(*s) && *s != '_'))
			return(0);
	return(1);
}

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

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

static int
checkname(cp)
register char *cp;
{
	if (!isalpha(*cp++) && *(cp-1) != '_')
		return(0);
	while (*cp)
		if (!isalnum(*cp++) && *(cp-1) != '_')
			return(0);
	return(1);
}

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

	for (vp = vlist; vp; vp = vp->next)
		if (vp->status & f && (isalpha(*vp->name) || *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);
		}
}

static 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 ^ */

static 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 -------- */

/*
 * All memory between (char *)areabot and (char *)(areatop+1) is
 * exclusively administered by the area management routines.
 * It is assumed that sbrk() and brk() manipulate the high end.
 */

#define sbrk(X) ({ void * __q = (void *)-1; if (brkaddr + (int)(X) < brktop) { __q = brkaddr; brkaddr+=(int)(X); } __q;})

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