ash.c

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

static int rootshell;

static void readcmdfile(char *);
static void cmdloop(int);

/*      $NetBSD: memalloc.h,v 1.13 2003/01/22 20:36:04 dsl Exp $        */


struct stackmark {
	struct stack_block *stackp;
	char *stacknxt;
	size_t stacknleft;
	struct stackmark *marknext;
};

/* minimum size of a block */
#define MINSIZE SHELL_ALIGN(504)

struct stack_block {
	struct stack_block *prev;
	char space[MINSIZE];
};

static struct stack_block stackbase;
static struct stack_block *stackp = &stackbase;
static struct stackmark *markp;
static char *stacknxt = stackbase.space;
static size_t stacknleft = MINSIZE;
static char *sstrend = stackbase.space + MINSIZE;
static int herefd = -1;


static pointer ckmalloc(size_t);
static pointer ckrealloc(pointer, size_t);
static char *savestr(const char *);
static pointer stalloc(size_t);
static void stunalloc(pointer);
static void setstackmark(struct stackmark *);
static void popstackmark(struct stackmark *);
static void growstackblock(void);
static void *growstackstr(void);
static char *makestrspace(size_t, char *);
static char *stnputs(const char *, size_t, char *);
static char *stputs(const char *, char *);


static inline char *_STPUTC(char c, char *p) {
	if (p == sstrend)
		p = growstackstr();
	*p++ = c;
	return p;
}

#define stackblock() ((void *)stacknxt)
#define stackblocksize() stacknleft
#define STARTSTACKSTR(p) ((p) = stackblock())
#define STPUTC(c, p) ((p) = _STPUTC((c), (p)))
#define CHECKSTRSPACE(n, p) \
	({ \
		char *q = (p); \
		size_t l = (n); \
		size_t m = sstrend - q; \
		if (l > m) \
			(p) = makestrspace(l, q); \
		0; \
	})
#define USTPUTC(c, p)   (*p++ = (c))
#define STACKSTRNUL(p)  ((p) == sstrend? (p = growstackstr(), *p = '\0') : (*p = '\0'))
#define STUNPUTC(p)     (--p)
#define STTOPC(p)       p[-1]
#define STADJUST(amount, p)     (p += (amount))

#define grabstackstr(p) stalloc((char *)(p) - (char *)stackblock())
#define ungrabstackstr(s, p) stunalloc((s))
#define stackstrend() ((void *)sstrend)

#define ckfree(p)       free((pointer)(p))

/*      $NetBSD: mystring.h,v 1.10 2002/11/24 22:35:42 christos Exp $   */


#define DOLATSTRLEN 4

static char *prefix(const char *, const char *);
static int number(const char *);
static int is_number(const char *);
static char *single_quote(const char *);
static char *sstrdup(const char *);

#define equal(s1, s2)   (strcmp(s1, s2) == 0)
#define scopy(s1, s2)   ((void)strcpy(s2, s1))

/*      $NetBSD: options.h,v 1.16 2003/01/22 20:36:04 dsl Exp $ */

struct shparam {
	int nparam;             /* # of positional parameters (without $0) */
	unsigned char malloc;   /* if parameter list dynamically allocated */
	char **p;               /* parameter list */
#ifdef CONFIG_ASH_GETOPTS
	int optind;             /* next parameter to be processed by getopts */
	int optoff;             /* used by getopts */
#endif
};


#define eflag optlist[0]
#define fflag optlist[1]
#define Iflag optlist[2]
#define iflag optlist[3]
#define mflag optlist[4]
#define nflag optlist[5]
#define sflag optlist[6]
#define xflag optlist[7]
#define vflag optlist[8]
#define Cflag optlist[9]
#define aflag optlist[10]
#define bflag optlist[11]
#define uflag optlist[12]
#define qflag optlist[13]

#ifdef DEBUG
#define nolog optlist[14]
#define debug optlist[15]
#define NOPTS   16
#else
#define NOPTS   14
#endif

/*      $NetBSD: options.c,v 1.33 2003/01/22 20:36:04 dsl Exp $ */


static const char *const optletters_optnames[NOPTS] = {
	"e"   "errexit",
	"f"   "noglob",
	"I"   "ignoreeof",
	"i"   "interactive",
	"m"   "monitor",
	"n"   "noexec",
	"s"   "stdin",
	"x"   "xtrace",
	"v"   "verbose",
	"C"   "noclobber",
	"a"   "allexport",
	"b"   "notify",
	"u"   "nounset",
	"q"   "quietprofile",
#ifdef DEBUG
	"\0"  "nolog",
	"\0"  "debug",
#endif
};

#define optletters(n) optletters_optnames[(n)][0]
#define optnames(n) (&optletters_optnames[(n)][1])


static char optlist[NOPTS];


static char *arg0;                     /* value of $0 */
static struct shparam shellparam;      /* $@ current positional parameters */
static char **argptr;                  /* argument list for builtin commands */
static char *optionarg;                /* set by nextopt (like getopt) */
static char *optptr;                   /* used by nextopt */

static char *minusc;                   /* argument to -c option */


static void procargs(int, char **);
static void optschanged(void);
static void setparam(char **);
static void freeparam(volatile struct shparam *);
static int shiftcmd(int, char **);
static int setcmd(int, char **);
static int nextopt(const char *);

/*      $NetBSD: redir.h,v 1.14 2002/11/24 22:35:43 christos Exp $      */

/* flags passed to redirect */
#define REDIR_PUSH 01           /* save previous values of file descriptors */
#define REDIR_SAVEFD2 03       /* set preverrout */

union node;
static void redirect(union node *, int);
static void popredir(int);
static void clearredir(int);
static int copyfd(int, int);
static int redirectsafe(union node *, int);

/*      $NetBSD: show.h,v 1.6 2003/01/22 20:36:04 dsl Exp $     */


#ifdef DEBUG
static void showtree(union node *);
static void trace(const char *, ...);
static void tracev(const char *, va_list);
static void trargs(char **);
static void trputc(int);
static void trputs(const char *);
static void opentrace(void);
#endif

/*      $NetBSD: trap.h,v 1.16 2002/11/24 22:35:43 christos Exp $       */


/* trap handler commands */
static char *trap[NSIG];
/* current value of signal */
static char sigmode[NSIG - 1];
/* indicates specified signal received */
static char gotsig[NSIG - 1];

static void clear_traps(void);
static void setsignal(int);
static void ignoresig(int);
static void onsig(int);
static void dotrap(void);
static void setinteractive(int);
static void exitshell(void) __attribute__((__noreturn__));
static int decode_signal(const char *, int);

/*
 * This routine is called when an error or an interrupt occurs in an
 * interactive shell and control is returned to the main command loop.
 */

static void
reset(void)
{
      /* from eval.c: */
      {
	      evalskip = 0;
	      loopnest = 0;
	      funcnest = 0;
      }

      /* from input.c: */
      {
	      parselleft = parsenleft = 0;      /* clear input buffer */
	      popallfiles();
      }

      /* from parser.c: */
      {
	      tokpushback = 0;
	      checkkwd = 0;
      }

      /* from redir.c: */
      {
	      clearredir(0);
      }

}

#ifdef CONFIG_ASH_ALIAS
static struct alias *atab[ATABSIZE];

static void setalias(const char *, const char *);
static struct alias *freealias(struct alias *);
static struct alias **__lookupalias(const char *);

static void
setalias(const char *name, const char *val)
{
	struct alias *ap, **app;

	app = __lookupalias(name);
	ap = *app;
	INTOFF;
	if (ap) {
		if (!(ap->flag & ALIASINUSE)) {
			ckfree(ap->val);
		}
		ap->val = savestr(val);
		ap->flag &= ~ALIASDEAD;
	} else {
		/* not found */
		ap = ckmalloc(sizeof (struct alias));
		ap->name = savestr(name);
		ap->val = savestr(val);
		ap->flag = 0;
		ap->next = 0;
		*app = ap;
	}
	INTON;
}

static int
unalias(const char *name)
{
	struct alias **app;

	app = __lookupalias(name);

	if (*app) {
		INTOFF;
		*app = freealias(*app);
		INTON;
		return (0);
	}

	return (1);
}

static void
rmaliases(void)
{
	struct alias *ap, **app;
	int i;

	INTOFF;
	for (i = 0; i < ATABSIZE; i++) {
		app = &atab[i];
		for (ap = *app; ap; ap = *app) {
			*app = freealias(*app);
			if (ap == *app) {
				app = &ap->next;
			}
		}
	}
	INTON;
}

static struct alias *
lookupalias(const char *name, int check)
{
	struct alias *ap = *__lookupalias(name);

	if (check && ap && (ap->flag & ALIASINUSE))
		return (NULL);
	return (ap);
}

/*
 * TODO - sort output
 */
static int
aliascmd(int argc, char **argv)
{
	char *n, *v;
	int ret = 0;
	struct alias *ap;

	if (argc == 1) {
		int i;

		for (i = 0; i < ATABSIZE; i++)
			for (ap = atab[i]; ap; ap = ap->next) {
				printalias(ap);
			}
		return (0);
	}
	while ((n = *++argv) != NULL) {
		if ((v = strchr(n+1, '=')) == NULL) { /* n+1: funny ksh stuff */
			if ((ap = *__lookupalias(n)) == NULL) {
				fprintf(stderr, "%s: %s not found\n", "alias", n);
				ret = 1;
			} else
				printalias(ap);
		} else {
			*v++ = '\0';
			setalias(n, v);
		}
	}

	return (ret);
}

static int
unaliascmd(int argc, char **argv)
{
	int i;

	while ((i = nextopt("a")) != '\0') {
		if (i == 'a') {
			rmaliases();
			return (0);
		}
	}
	for (i = 0; *argptr; argptr++) {
		if (unalias(*argptr)) {
			fprintf(stderr, "%s: %s not found\n", "unalias", *argptr);
			i = 1;
		}
	}

	return (i);
}

static struct alias *
freealias(struct alias *ap) {
	struct alias *next;

	if (ap->flag & ALIASINUSE) {
		ap->flag |= ALIASDEAD;
		return ap;
	}

	next = ap->next;
	ckfree(ap->name);
	ckfree(ap->val);
	ckfree(ap);
	return next;
}

static void
printalias(const struct alias *ap) {
	out1fmt("%s=%s\n", ap->name, single_quote(ap->val));
}

static struct alias **
__lookupalias(const char *name) {
	unsigned int hashval;
	struct alias **app;
	const char *p;
	unsigned int ch;

	p = name;

	ch = (unsigned char)*p;
	hashval = ch << 4;
	while (ch) {
		hashval += ch;
		ch = (unsigned char)*++p;
	}
	app = &atab[hashval % ATABSIZE];

	for (; *app; app = &(*app)->next) {
		if (equal(name, (*app)->name)) {
			break;
		}
	}

	return app;
}
#endif /* CONFIG_ASH_ALIAS */


/*      $NetBSD: cd.c,v 1.30 2003/01/22 20:36:03 dsl Exp $      */

/*
 * The cd and pwd commands.
 */

#define CD_PHYSICAL 1
#define CD_PRINT 2

static int docd(const char *, int);
static int cdopt(void);

static char *curdir = nullstr;          /* current working directory */
static char *physdir = nullstr;         /* physical working director