ash.c

来自「为samsung2410 ARM移植的busybox工具包」· C语言 代码 · 共 2,530 行 · 第 1/5 页

      0,       0,       0,       0,
      0,       0,       0,       0,
      0,       0,       0,       0,
      0,       0,       0,       0,
      0,       0,       0,       0,
      0,       0,       0,       0,
      0,       0,       0,       0,
      0,       0,       0,       ISSPECL,
      0,       ISSPECL, ISSPECL, 0,
      0,       0,       0,       0,
      ISSPECL, 0,       0,       ISSPECL,
      0,       0,       ISDIGIT, ISDIGIT,
      ISDIGIT, ISDIGIT, ISDIGIT, ISDIGIT,
      ISDIGIT, ISDIGIT, ISDIGIT, ISDIGIT,
      0,       0,       0,       0,
      0,       ISSPECL, ISSPECL, ISUPPER,
      ISUPPER, ISUPPER, ISUPPER, ISUPPER,
      ISUPPER, ISUPPER, ISUPPER, ISUPPER,
      ISUPPER, ISUPPER, ISUPPER, ISUPPER,
      ISUPPER, ISUPPER, ISUPPER, ISUPPER,
      ISUPPER, ISUPPER, ISUPPER, ISUPPER,
      ISUPPER, ISUPPER, ISUPPER, ISUPPER,
      ISUPPER, 0,       0,       0,
      0,       ISUNDER, 0,       ISLOWER,
      ISLOWER, ISLOWER, ISLOWER, ISLOWER,
      ISLOWER, ISLOWER, ISLOWER, ISLOWER,
      ISLOWER, ISLOWER, ISLOWER, ISLOWER,
      ISLOWER, ISLOWER, ISLOWER, ISLOWER,
      ISLOWER, ISLOWER, ISLOWER, ISLOWER,
      ISLOWER, ISLOWER, ISLOWER, ISLOWER,
      ISLOWER, 0,       0,       0,
      0
};

/* Array indicating which tokens mark the end of a list */
static const char tokendlist[] = {
	1,
	0,
	0,
	0,
	0,
	0,
	0,
	0,
	1,
	1,
	1,
	0,
	0,
	0,
	0,
	0,
	1,
	1,
	1,
	1,
	1,
	1,
	0,
	0,
	0,
	1,
	0,
	0,
	0,
	1,
};

static const char *const tokname[] = {
	"end of file",
	"newline",
	"\";\"",
	"\"&\"",
	"\"&&\"",
	"\"||\"",
	"\"|\"",
	"\"(\"",
	"\")\"",
	"\";;\"",
	"\"`\"",
	"redirection",
	"word",
	"assignment",
	"\"!\"",
	"\"case\"",
	"\"do\"",
	"\"done\"",
	"\"elif\"",
	"\"else\"",
	"\"esac\"",
	"\"fi\"",
	"\"for\"",
	"\"if\"",
	"\"in\"",
	"\"then\"",
	"\"until\"",
	"\"while\"",
	"\"{\"",
	"\"}\"",
};

#define KWDOFFSET 14

static const char *const parsekwd[] = {
	"!",
	"case",
	"do",
	"done",
	"elif",
	"else",
	"esac",
	"fi",
	"for",
	"if",
	"in",
	"then",
	"until",
	"while",
	"{",
	"}"
};


static int plinno = 1;          /* input line number */

static int parselleft;          /* copy of parsefile->lleft */

static struct parsefile basepf; /* top level input file */
static char basebuf[BUFSIZ];    /* buffer for top level input file */
static struct parsefile *parsefile = &basepf;  /* current input file */

/*
 * NEOF is returned by parsecmd when it encounters an end of file.  It
 * must be distinct from NULL, so we use the address of a variable that
 * happens to be handy.
 */

static int tokpushback;         /* last token pushed back */
#define NEOF ((union node *)&tokpushback)
static int checkkwd;            /* 1 == check for kwds, 2 == also eat newlines */


static void error (const char *, ...) __attribute__((__noreturn__));
static void exerror (int, const char *, ...) __attribute__((__noreturn__));
static void shellexec (char **, char **, const char *, int)
    __attribute__((noreturn));
static void exitshell (int) __attribute__((noreturn));

static int  goodname(const char *);
static void ignoresig (int);
static void onsig (int);
static void dotrap (void);
static int  decode_signal (const char *, int);

static void shprocvar(void);
static void deletefuncs(void);
static void setparam (char **);
static void freeparam (volatile struct shparam *);

/* reasons for skipping commands (see comment on breakcmd routine) */
#define SKIPBREAK       1
#define SKIPCONT        2
#define SKIPFUNC        3
#define SKIPFILE        4

/* values of cmdtype */
#define CMDUNKNOWN -1           /* no entry in table for command */
#define CMDNORMAL 0             /* command is an executable program */
#define CMDBUILTIN 1            /* command is a shell builtin */
#define CMDFUNCTION 2           /* command is a shell function */

#define DO_ERR  1               /* find_command prints errors */
#define DO_ABS  2               /* find_command checks absolute paths */
#define DO_NOFUN        4       /* find_command ignores functions */
#define DO_BRUTE        8       /* find_command ignores hash table */

/*
 * Shell variables.
 */

/* flags */
#define VEXPORT         0x01    /* variable is exported */
#define VREADONLY       0x02    /* variable cannot be modified */
#define VSTRFIXED       0x04    /* variable struct is staticly allocated */
#define VTEXTFIXED      0x08    /* text is staticly allocated */
#define VSTACK          0x10    /* text is allocated on the stack */
#define VUNSET          0x20    /* the variable is not set */
#define VNOFUNC         0x40    /* don't call the callback function */


struct var {
	struct var *next;               /* next entry in hash list */
	int flags;                      /* flags are defined above */
	char *text;                     /* name=value */
	void (*func) (const char *);
					/* function to be called when  */
					/* the variable gets set/unset */
};

struct localvar {
	struct localvar *next;          /* next local variable in list */
	struct var *vp;                 /* the variable that was made local */
	int flags;                      /* saved flags */
	char *text;                     /* saved text */
};


#if defined(__GLIBC__) && __GLIBC__ >= 2 && !defined(FNMATCH_BROKEN)
#define rmescapes(p) _rmescapes((p), 0)
static char *_rmescapes (char *, int);
#else
static void rmescapes (char *);
#endif

static int  casematch (union node *, const char *);
static void clearredir(void);
static void popstring(void);
static void readcmdfile (const char *);

static int number (const char *);
static int is_number (const char *, int *num);
static char *single_quote (const char *);
static int nextopt (const char *);

static void redirect (union node *, int);
static void popredir (void);
static int dup_as_newfd (int, int);

static void changepath(const char *newval);
static void getoptsreset(const char *value);


static int parsenleft;                  /* copy of parsefile->nleft */
static char *parsenextc;                /* copy of parsefile->nextc */
static int rootpid;     /* pid of main shell */
static int rootshell;   /* true if we aren't a child of the main shell */

static const char spcstr[] = " ";
static const char snlfmt[] = "%s\n";

static int sstrnleft;
static int herefd = -1;

static struct localvar *localvars;

static struct var vifs;
static struct var vmail;
static struct var vmpath;
static struct var vpath;
static struct var vps1;
static struct var vps2;
static struct var voptind;
#ifdef BB_LOCALE_SUPPORT
static struct var vlc_all;
static struct var vlc_ctype;
#endif

struct varinit {
	struct var *var;
	int flags;
	const char *text;
	void (*func) (const char *);
};

static const char defpathvar[] =
	"PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin";
#define defpath (defpathvar + 5)

#ifdef IFS_BROKEN
static const char defifsvar[] = "IFS= \t\n";
#define defifs (defifsvar + 4)
#else
static const char defifs[] = " \t\n";
#endif

static const struct varinit varinit[] = {
#ifdef IFS_BROKEN
	{ &vifs,        VSTRFIXED|VTEXTFIXED,           defifsvar,
#else
	{ &vifs,        VSTRFIXED|VTEXTFIXED|VUNSET,    "IFS=",
#endif
	  NULL },
	{ &vmail,       VSTRFIXED|VTEXTFIXED|VUNSET,    "MAIL=",
	  NULL },
	{ &vmpath,      VSTRFIXED|VTEXTFIXED|VUNSET,    "MAILPATH=",
	  NULL },
	{ &vpath,       VSTRFIXED|VTEXTFIXED,           defpathvar,
	  changepath },
	/*
	 * vps1 depends on uid
	 */
	{ &vps2,        VSTRFIXED|VTEXTFIXED,           "PS2=> ",
	  NULL },
	{ &voptind,     VSTRFIXED|VTEXTFIXED,           "OPTIND=1",
	  getoptsreset },
#ifdef BB_LOCALE_SUPPORT
	{ &vlc_all,     VSTRFIXED|VTEXTFIXED|VUNSET,    "LC_ALL=",
	  change_lc_all },
	{ &vlc_ctype,   VSTRFIXED|VTEXTFIXED|VUNSET,    "LC_CTYPE=",
	  change_lc_ctype },
#endif
	{ NULL, 0,                              NULL,
	  NULL }
};

#define VTABSIZE 39

static struct var *vartab[VTABSIZE];

/*
 * The following macros access the values of the above variables.
 * They have to skip over the name.  They return the null string
 * for unset variables.
 */

#define ifsval()        (vifs.text + 4)
#define ifsset()        ((vifs.flags & VUNSET) == 0)
#define mailval()       (vmail.text + 5)
#define mpathval()      (vmpath.text + 9)
#define pathval()       (vpath.text + 5)
#define ps1val()        (vps1.text + 4)
#define ps2val()        (vps2.text + 4)
#define optindval()     (voptind.text + 7)

#define mpathset()      ((vmpath.flags & VUNSET) == 0)

static void initvar (void);
static void setvar (const char *, const char *, int);
static void setvareq (char *, int);
static void listsetvar (struct strlist *);
static const char *lookupvar (const char *);
static const char *bltinlookup (const char *);
static char **environment (void);
static int showvarscmd (int, char **);
static void mklocal (char *);
static void poplocalvars (void);
static int unsetvar (const char *);
static int varequal (const char *, const char *);


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 */


#ifdef ASH_ALIAS

#define ALIASINUSE      1
#define ALIASDEAD       2

#define ATABSIZE 39

struct alias {
	struct alias *next;
	char *name;
	char *val;
	int flag;
};

static struct alias *atab[ATABSIZE];

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

static void
setalias(name, val)
	char *name, *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(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);
}

static void
printalias(const struct alias *ap) {
	char *p;

	p = single_quote(ap->val);
	printf("alias %s=%s\n", ap->name, p);
	stunalloc(p);
}


/*
 * 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) {
				out2fmt("%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)) {
			out2fmt("%s: %s not found\n", "unalias", *argptr);
			i = 1;
		}
	}