text: /* vi: set sw=4 ts=4: */
  /*
   * test implementation for busybox
   *
   * Copyright (c) by a whole pile of folks:
   *
   *     test(1); version 7-like  --  author Erik Baalbergen
   *     modified by Eric Gisin to be used as built-in.
   *     modified by Arnold Robbins to add SVR3 compatibility
   *     (-x -c -b -p -u -g -k) plus Korn's -L -nt -ot -ef and new -S (socket).
   *     modified by J.T. Conklin for NetBSD.
   *     modified by Herbert Xu to be used as built-in in ash.
   *     modified by Erik Andersen <andersen@codepoet.org> to be used
   *     in busybox.
   *     modified by Bernhard Reutner-Fischer to be useable (i.e. a bit less bloaty).
   *
   * Licensed under GPLv2 or later, see file LICENSE in this source tree.
   *
   * Original copyright notice states:
   *     "This program is in the Public Domain."
   */
  //config:config TEST
  //config:	bool "test (3.6 kb)"
  //config:	default y
  //config:	help
  //config:	test is used to check file types and compare values,
  //config:	returning an appropriate exit code. The bash shell
  //config:	has test built in, ash can build it in optionally.
  //config:
  //config:config TEST1
  //config:	bool "test as ["
  //config:	default y
  //config:	help
  //config:	Provide test command in the "[ EXPR ]" form
  //config:
  //config:config TEST2
  //config:	bool "test as [["
  //config:	default y
  //config:	help
  //config:	Provide test command in the "[[ EXPR ]]" form
  //config:
  //config:config FEATURE_TEST_64
  //config:	bool "Extend test to 64 bit"
  //config:	default y
  //config:	depends on TEST || TEST1 || TEST2 || ASH_TEST || HUSH_TEST
  //config:	help
  //config:	Enable 64-bit support in test.
  
  //applet:IF_TEST(APPLET_NOFORK(test, test, BB_DIR_USR_BIN, BB_SUID_DROP, test))
  //applet:IF_TEST1(APPLET_NOFORK([,   test, BB_DIR_USR_BIN, BB_SUID_DROP, test))
  //applet:IF_TEST2(APPLET_NOFORK([[,  test, BB_DIR_USR_BIN, BB_SUID_DROP, test))
  
  //kbuild:lib-$(CONFIG_TEST)  += test.o test_ptr_hack.o
  //kbuild:lib-$(CONFIG_TEST1) += test.o test_ptr_hack.o
  //kbuild:lib-$(CONFIG_TEST2) += test.o test_ptr_hack.o
  
  //kbuild:lib-$(CONFIG_ASH_TEST)  += test.o test_ptr_hack.o
  //kbuild:lib-$(CONFIG_HUSH_TEST) += test.o test_ptr_hack.o
  
  /* "test --help" is special-cased to ignore --help */
  //usage:#define test_trivial_usage NOUSAGE_STR
  //usage:#define test_full_usage ""
  //usage:
  //usage:#define test_example_usage
  //usage:       "$ test 1 -eq 2\n"
  //usage:       "$ echo $?\n"
  //usage:       "1\n"
  //usage:       "$ test 1 -eq 1\n"
  //usage:       "$ echo $?\n"
  //usage:       "0\n"
  //usage:       "$ [ -d /etc ]\n"
  //usage:       "$ echo $?\n"
  //usage:       "0\n"
  //usage:       "$ [ -d /junk ]\n"
  //usage:       "$ echo $?\n"
  //usage:       "1\n"
  
  #include "libbb.h"
  #include <setjmp.h>
  
  /* This is a NOFORK applet. Be very careful! */
  
  /* test_main() is called from shells, and we need to be extra careful here.
   * This is true regardless of PREFER_APPLETS and SH_STANDALONE
   * state. */
  
  /* test(1) accepts the following grammar:
  	oexpr   ::= aexpr | aexpr "-o" oexpr ;
  	aexpr   ::= nexpr | nexpr "-a" aexpr ;
  	nexpr   ::= primary | "!" primary
  	primary ::= unary-operator operand
  		| operand binary-operator operand
  		| operand
  		| "(" oexpr ")"
  		;
  	unary-operator ::= "-r"|"-w"|"-x"|"-f"|"-d"|"-c"|"-b"|"-p"|
  		"-u"|"-g"|"-k"|"-s"|"-t"|"-z"|"-n"|"-o"|"-O"|"-G"|"-L"|"-S";
  
  	binary-operator ::= "="|"=="|"!="|"-eq"|"-ne"|"-ge"|"-gt"|"-le"|"-lt"|
  			"-nt"|"-ot"|"-ef";
  	operand ::= <any legal UNIX file name>
  */
  
  /* TODO: handle [[ expr ]] bashism bash-compatibly.
   * [[ ]] is meant to be a "better [ ]", with less weird syntax
   * and without the risk of variables and quoted strings misinterpreted
   * as operators.
   * This will require support from shells - we need to know quote status
   * of each parameter (see below).
   *
   * Word splitting and pathname expansion should NOT be performed:
   *      # a="a b"; [[ $a = "a b" ]] && echo YES
   *      YES
   *      # [[ /bin/m* ]] && echo YES
   *      YES
   *
   * =~ should do regexp match
   * = and == should do pattern match against right side:
   *      # [[ *a* == bab ]] && echo YES
   *      # [[ bab == *a* ]] && echo YES
   *      YES
   * != does the negated == (i.e., also with pattern matching).
   * Pattern matching is quotation-sensitive:
   *      # [[ bab == "b"a* ]] && echo YES
   *      YES
   *      # [[ bab == b"a*" ]] && echo YES
   *
   * Conditional operators such as -f must be unquoted literals to be recognized:
   *      # [[ -e /bin ]] && echo YES
   *      YES
   *      # [[ '-e' /bin ]] && echo YES
   *      bash: conditional binary operator expected...
   *      # A='-e'; [[ $A /bin ]] && echo YES
   *      bash: conditional binary operator expected...
   *
   * || and && should work as -o and -a work in [ ]
   * -a and -o aren't recognized (&& and || are to be used instead)
   * ( and ) do not need to be quoted unlike in [ ]:
   *      # [[ ( abc ) && '' ]] && echo YES
   *      # [[ ( abc ) || '' ]] && echo YES
   *      YES
   *      # [[ ( abc ) -o '' ]] && echo YES
   *      bash: syntax error in conditional expression...
   *
   * Apart from the above, [[ expr ]] should work as [ expr ]
   */
  
  #define TEST_DEBUG 0
  
  enum token {
  	EOI,
  
  	FILRD, /* file access */
  	FILWR,
  	FILEX,
  
  	FILEXIST,
  
  	FILREG, /* file type */
  	FILDIR,
  	FILCDEV,
  	FILBDEV,
  	FILFIFO,
  	FILSOCK,
  
  	FILSYM,
  	FILGZ,
  	FILTT,
  
  	FILSUID, /* file bit */
  	FILSGID,
  	FILSTCK,
  
  	FILNT, /* file ops */
  	FILOT,
  	FILEQ,
  
  	FILUID,
  	FILGID,
  
  	STREZ, /* str ops */
  	STRNZ,
  	STREQ,
  	STRNE,
  	STRLT,
  	STRGT,
  
  	INTEQ, /* int ops */
  	INTNE,
  	INTGE,
  	INTGT,
  	INTLE,
  	INTLT,
  
  	UNOT,
  	BAND,
  	BOR,
  	LPAREN,
  	RPAREN,
  	OPERAND
  };
  #define is_int_op(a)      (((unsigned char)((a) - INTEQ)) <= 5)
  #define is_str_op(a)      (((unsigned char)((a) - STREZ)) <= 5)
  #define is_file_op(a)     (((unsigned char)((a) - FILNT)) <= 2)
  #define is_file_access(a) (((unsigned char)((a) - FILRD)) <= 2)
  #define is_file_type(a)   (((unsigned char)((a) - FILREG)) <= 5)
  #define is_file_bit(a)    (((unsigned char)((a) - FILSUID)) <= 2)
  
  #if TEST_DEBUG
  int depth;
  #define nest_msg(...) do { \
  	depth++; \
  	fprintf(stderr, "%*s", depth*2, ""); \
  	fprintf(stderr, __VA_ARGS__); \
  } while (0)
  #define unnest_msg(...) do { \
  	fprintf(stderr, "%*s", depth*2, ""); \
  	fprintf(stderr, __VA_ARGS__); \
  	depth--; \
  } while (0)
  #define dbg_msg(...) do { \
  	fprintf(stderr, "%*s", depth*2, ""); \
  	fprintf(stderr, __VA_ARGS__); \
  } while (0)
  #define unnest_msg_and_return(expr, ...) do { \
  	number_t __res = (expr); \
  	fprintf(stderr, "%*s", depth*2, ""); \
  	fprintf(stderr, __VA_ARGS__, res); \
  	depth--; \
  	return __res; \
  } while (0)
  static const char *const TOKSTR[] = {
  	"EOI",
  	"FILRD",
  	"FILWR",
  	"FILEX",
  	"FILEXIST",
  	"FILREG",
  	"FILDIR",
  	"FILCDEV",
  	"FILBDEV",
  	"FILFIFO",
  	"FILSOCK",
  	"FILSYM",
  	"FILGZ",
  	"FILTT",
  	"FILSUID",
  	"FILSGID",
  	"FILSTCK",
  	"FILNT",
  	"FILOT",
  	"FILEQ",
  	"FILUID",
  	"FILGID",
  	"STREZ",
  	"STRNZ",
  	"STREQ",
  	"STRNE",
  	"STRLT",
  	"STRGT",
  	"INTEQ",
  	"INTNE",
  	"INTGE",
  	"INTGT",
  	"INTLE",
  	"INTLT",
  	"UNOT",
  	"BAND",
  	"BOR",
  	"LPAREN",
  	"RPAREN",
  	"OPERAND"
  };
  #else
  #define nest_msg(...)   ((void)0)
  #define unnest_msg(...) ((void)0)
  #define dbg_msg(...)    ((void)0)
  #define unnest_msg_and_return(expr, ...) return expr
  #endif
  
  enum {
  	UNOP,
  	BINOP,
  	BUNOP,
  	BBINOP,
  	PAREN
  };
  
  struct operator_t {
  	unsigned char op_num, op_type;
  };
  
  static const struct operator_t ops_table[] = {
  	{ /* "-r" */ FILRD   , UNOP   },
  	{ /* "-w" */ FILWR   , UNOP   },
  	{ /* "-x" */ FILEX   , UNOP   },
  	{ /* "-e" */ FILEXIST, UNOP   },
  	{ /* "-f" */ FILREG  , UNOP   },
  	{ /* "-d" */ FILDIR  , UNOP   },
  	{ /* "-c" */ FILCDEV , UNOP   },
  	{ /* "-b" */ FILBDEV , UNOP   },
  	{ /* "-p" */ FILFIFO , UNOP   },
  	{ /* "-u" */ FILSUID , UNOP   },
  	{ /* "-g" */ FILSGID , UNOP   },
  	{ /* "-k" */ FILSTCK , UNOP   },
  	{ /* "-s" */ FILGZ   , UNOP   },
  	{ /* "-t" */ FILTT   , UNOP   },
  	{ /* "-z" */ STREZ   , UNOP   },
  	{ /* "-n" */ STRNZ   , UNOP   },
  	{ /* "-h" */ FILSYM  , UNOP   },    /* for backwards compat */
  
  	{ /* "-O" */ FILUID  , UNOP   },
  	{ /* "-G" */ FILGID  , UNOP   },
  	{ /* "-L" */ FILSYM  , UNOP   },
  	{ /* "-S" */ FILSOCK , UNOP   },
  	{ /* "="  */ STREQ   , BINOP  },
  	{ /* "==" */ STREQ   , BINOP  },
  	{ /* "!=" */ STRNE   , BINOP  },
  	{ /* "<"  */ STRLT   , BINOP  },
  	{ /* ">"  */ STRGT   , BINOP  },
  	{ /* "-eq"*/ INTEQ   , BINOP  },
  	{ /* "-ne"*/ INTNE   , BINOP  },
  	{ /* "-ge"*/ INTGE   , BINOP  },
  	{ /* "-gt"*/ INTGT   , BINOP  },
  	{ /* "-le"*/ INTLE   , BINOP  },
  	{ /* "-lt"*/ INTLT   , BINOP  },
  	{ /* "-nt"*/ FILNT   , BINOP  },
  	{ /* "-ot"*/ FILOT   , BINOP  },
  	{ /* "-ef"*/ FILEQ   , BINOP  },
  	{ /* "!"  */ UNOT    , BUNOP  },
  	{ /* "-a" */ BAND    , BBINOP },
  	{ /* "-o" */ BOR     , BBINOP },
  	{ /* "("  */ LPAREN  , PAREN  },
  	{ /* ")"  */ RPAREN  , PAREN  },
  };
  /* Please keep these two tables in sync */
  static const char ops_texts[] ALIGN1 =
  	"-r"  "\0"
  	"-w"  "\0"
  	"-x"  "\0"
  	"-e"  "\0"
  	"-f"  "\0"
  	"-d"  "\0"
  	"-c"  "\0"
  	"-b"  "\0"
  	"-p"  "\0"
  	"-u"  "\0"
  	"-g"  "\0"
  	"-k"  "\0"
  	"-s"  "\0"
  	"-t"  "\0"
  	"-z"  "\0"
  	"-n"  "\0"
  	"-h"  "\0"
  
  	"-O"  "\0"
  	"-G"  "\0"
  	"-L"  "\0"
  	"-S"  "\0"
  	"="   "\0"
  	"=="  "\0"
  	"!="  "\0"
  	"<"   "\0"
  	">"   "\0"
  	"-eq" "\0"
  	"-ne" "\0"
  	"-ge" "\0"
  	"-gt" "\0"
  	"-le" "\0"
  	"-lt" "\0"
  	"-nt" "\0"
  	"-ot" "\0"
  	"-ef" "\0"
  	"!"   "\0"
  	"-a"  "\0"
  	"-o"  "\0"
  	"("   "\0"
  	")"   "\0"
  ;
  
  
  #if ENABLE_FEATURE_TEST_64
  typedef int64_t number_t;
  #else
  typedef int number_t;
  #endif
  
  
  /* We try to minimize both static and stack usage. */
  struct test_statics {
  	char **args;
  	/* set only by check_operator(), either to bogus struct
  	 * or points to matching operator_t struct. Never NULL. */
  	const struct operator_t *last_operator;
  	gid_t *group_array;
  	int ngroups;
  	jmp_buf leaving;
  };
  
  /* See test_ptr_hack.c */
  extern struct test_statics *const test_ptr_to_statics;
  
  #define S (*test_ptr_to_statics)
  #define args            (S.args         )
  #define last_operator   (S.last_operator)
  #define group_array     (S.group_array  )
  #define ngroups         (S.ngroups      )
  #define leaving         (S.leaving      )
  
  #define INIT_S() do { \
  	(*(struct test_statics**)&test_ptr_to_statics) = xzalloc(sizeof(S)); \
  	barrier(); \
  } while (0)
  #define DEINIT_S() do { \
  	free(group_array); \
  	free(test_ptr_to_statics); \
  } while (0)
  
  static number_t primary(enum token n);
  
  static void syntax(const char *op, const char *msg) NORETURN;
  static void syntax(const char *op, const char *msg)
  {
  	if (op && *op) {
  		bb_error_msg("%s: %s", op, msg);
  	} else {
  		bb_error_msg("%s: %s"+4, msg);
  	}
  	longjmp(leaving, 2);
  }
  
  /* atoi with error detection */
  //XXX: FIXME: duplicate of existing libbb function?
  static number_t getn(const char *s)
  {
  	char *p;
  #if ENABLE_FEATURE_TEST_64
  	long long r;
  #else
  	long r;
  #endif
  
  	errno = 0;
  #if ENABLE_FEATURE_TEST_64
  	r = strtoll(s, &p, 10);
  #else
  	r = strtol(s, &p, 10);
  #endif
  
  	if (errno != 0)
  		syntax(s, "out of range");
  
  	if (p == s || *(skip_whitespace(p)) != '\0')
  		syntax(s, "bad number");
  
  	return r;
  }
  
  /* UNUSED
  static int newerf(const char *f1, const char *f2)
  {
  	struct stat b1, b2;
  
  	return (stat(f1, &b1) == 0 &&
  			stat(f2, &b2) == 0 && b1.st_mtime > b2.st_mtime);
  }
  
  static int olderf(const char *f1, const char *f2)
  {
  	struct stat b1, b2;
  
  	return (stat(f1, &b1) == 0 &&
  			stat(f2, &b2) == 0 && b1.st_mtime < b2.st_mtime);
  }
  
  static int equalf(const char *f1, const char *f2)
  {
  	struct stat b1, b2;
  
  	return (stat(f1, &b1) == 0 &&
  			stat(f2, &b2) == 0 &&
  			b1.st_dev == b2.st_dev && b1.st_ino == b2.st_ino);
  }
  */
  
  
  static enum token check_operator(const char *s)
  {
  	static const struct operator_t no_op = {
  		.op_num = -1,
  		.op_type = -1
  	};
  	int n;
  
  	last_operator = &no_op;
  	if (s == NULL)
  		return EOI;
  	n = index_in_strings(ops_texts, s);
  	if (n < 0)
  		return OPERAND;
  	last_operator = &ops_table[n];
  	return ops_table[n].op_num;
  }
  
  
  static int binop(void)
  {
  	const char *opnd1, *opnd2;
  	const struct operator_t *op;
  	number_t val1, val2;
  
  	opnd1 = *args;
  	check_operator(*++args);
  	op = last_operator;
  
  	opnd2 = *++args;
  	if (opnd2 == NULL)
  		syntax(args[-1], "argument expected");
  
  	if (is_int_op(op->op_num)) {
  		val1 = getn(opnd1);
  		val2 = getn(opnd2);
  		if (op->op_num == INTEQ)
  			return val1 == val2;
  		if (op->op_num == INTNE)
  			return val1 != val2;
  		if (op->op_num == INTGE)
  			return val1 >= val2;
  		if (op->op_num == INTGT)
  			return val1 >  val2;
  		if (op->op_num == INTLE)
  			return val1 <= val2;
  		/*if (op->op_num == INTLT)*/
  		return val1 <  val2;
  	}
  	if (is_str_op(op->op_num)) {
  		val1 = strcmp(opnd1, opnd2);
  		if (op->op_num == STREQ)
  			return val1 == 0;
  		if (op->op_num == STRNE)
  			return val1 != 0;
  		if (op->op_num == STRLT)
  			return val1 < 0;
  		/*if (op->op_num == STRGT)*/
  		return val1 > 0;
  	}
  	/* We are sure that these three are by now the only binops we didn't check
  	 * yet, so we do not check if the class is correct:
  	 */
  /*	if (is_file_op(op->op_num)) */
  	{
  		struct stat b1, b2;
  
  		if (stat(opnd1, &b1) || stat(opnd2, &b2))
  			return 0; /* false, since at least one stat failed */
  		if (op->op_num == FILNT)
  			return b1.st_mtime > b2.st_mtime;
  		if (op->op_num == FILOT)
  			return b1.st_mtime < b2.st_mtime;
  		/*if (op->op_num == FILEQ)*/
  		return b1.st_dev == b2.st_dev && b1.st_ino == b2.st_ino;
  	}
  	/*return 1; - NOTREACHED */
  }
  
  static void initialize_group_array(void)
  {
  	group_array = bb_getgroups(&ngroups, NULL);
  }
  
  /* Return non-zero if GID is one that we have in our groups list. */
  //XXX: FIXME: duplicate of existing libbb function?
  // see toplevel TODO file:
  // possible code duplication ingroup() and is_a_group_member()
  static int is_a_group_member(gid_t gid)
  {
  	int i;
  
  	/* Short-circuit if possible, maybe saving a call to getgroups(). */
  	if (gid == getgid() || gid == getegid())
  		return 1;
  
  	if (ngroups == 0)
  		initialize_group_array();
  
  	/* Search through the list looking for GID. */
  	for (i = 0; i < ngroups; i++)
  		if (gid == group_array[i])
  			return 1;
  
  	return 0;
  }
  
  
  /* Do the same thing access(2) does, but use the effective uid and gid,
     and don't make the mistake of telling root that any file is
     executable. */
  static int test_eaccess(struct stat *st, int mode)
  {
  	unsigned int euid = geteuid();
  
  	if (euid == 0) {
  		/* Root can read or write any file. */
  		if (mode != X_OK)
  			return 0;
  
  		/* Root can execute any file that has any one of the execute
  		 * bits set. */
  		if (st->st_mode & (S_IXUSR | S_IXGRP | S_IXOTH))
  			return 0;
  	}
  
  	if (st->st_uid == euid)  /* owner */
  		mode <<= 6;
  	else if (is_a_group_member(st->st_gid))
  		mode <<= 3;
  
  	if (st->st_mode & mode)
  		return 0;
  
  	return -1;
  }
  
  
  static int filstat(char *nm, enum token mode)
  {
  	struct stat s;
  	unsigned i = i; /* gcc 3.x thinks it can be used uninitialized */
  
  	if (mode == FILSYM) {
  #ifdef S_IFLNK
  		if (lstat(nm, &s) == 0) {
  			i = S_IFLNK;
  			goto filetype;
  		}
  #endif
  		return 0;
  	}
  
  	if (stat(nm, &s) != 0)
  		return 0;
  	if (mode == FILEXIST)
  		return 1;
  	if (is_file_access(mode)) {
  		if (mode == FILRD)
  			i = R_OK;
  		if (mode == FILWR)
  			i = W_OK;
  		if (mode == FILEX)
  			i = X_OK;
  		return test_eaccess(&s, i) == 0;
  	}
  	if (is_file_type(mode)) {
  		if (mode == FILREG)
  			i = S_IFREG;
  		if (mode == FILDIR)
  			i = S_IFDIR;
  		if (mode == FILCDEV)
  			i = S_IFCHR;
  		if (mode == FILBDEV)
  			i = S_IFBLK;
  		if (mode == FILFIFO) {
  #ifdef S_IFIFO
  			i = S_IFIFO;
  #else
  			return 0;
  #endif
  		}
  		if (mode == FILSOCK) {
  #ifdef S_IFSOCK
  			i = S_IFSOCK;
  #else
  			return 0;
  #endif
  		}
   filetype:
  		return ((s.st_mode & S_IFMT) == i);
  	}
  	if (is_file_bit(mode)) {
  		if (mode == FILSUID)
  			i = S_ISUID;
  		if (mode == FILSGID)
  			i = S_ISGID;
  		if (mode == FILSTCK)
  			i = S_ISVTX;
  		return ((s.st_mode & i) != 0);
  	}
  	if (mode == FILGZ)
  		return s.st_size > 0L;
  	if (mode == FILUID)
  		return s.st_uid == geteuid();
  	if (mode == FILGID)
  		return s.st_gid == getegid();
  	return 1; /* NOTREACHED */
  }
  
  
  static number_t nexpr(enum token n)
  {
  	number_t res;
  
  	nest_msg(">nexpr(%s)\n", TOKSTR[n]);
  	if (n == UNOT) {
  		n = check_operator(*++args);
  		if (n == EOI) {
  			/* special case: [ ! ], [ a -a ! ] are valid */
  			/* IOW, "! ARG" may miss ARG */
  			args--;
  			unnest_msg("<nexpr:1 (!EOI), args:%s(%p)\n", args[0], &args[0]);
  			return 1;
  		}
  		res = !nexpr(n);
  		unnest_msg("<nexpr:%lld\n", res);
  		return res;
  	}
  	res = primary(n);
  	unnest_msg("<nexpr:%lld\n", res);
  	return res;
  }
  
  
  static number_t aexpr(enum token n)
  {
  	number_t res;
  
  	nest_msg(">aexpr(%s)\n", TOKSTR[n]);
  	res = nexpr(n);
  	dbg_msg("aexpr: nexpr:%lld, next args:%s(%p)\n", res, args[1], &args[1]);
  	if (check_operator(*++args) == BAND) {
  		dbg_msg("aexpr: arg is AND, next args:%s(%p)\n", args[1], &args[1]);
  		res = aexpr(check_operator(*++args)) && res;
  		unnest_msg("<aexpr:%lld\n", res);
  		return res;
  	}
  	args--;
  	unnest_msg("<aexpr:%lld, args:%s(%p)\n", res, args[0], &args[0]);
  	return res;
  }
  
  
  static number_t oexpr(enum token n)
  {
  	number_t res;
  
  	nest_msg(">oexpr(%s)\n", TOKSTR[n]);
  	res = aexpr(n);
  	dbg_msg("oexpr: aexpr:%lld, next args:%s(%p)\n", res, args[1], &args[1]);
  	if (check_operator(*++args) == BOR) {
  		dbg_msg("oexpr: next arg is OR, next args:%s(%p)\n", args[1], &args[1]);
  		res = oexpr(check_operator(*++args)) || res;
  		unnest_msg("<oexpr:%lld\n", res);
  		return res;
  	}
  	args--;
  	unnest_msg("<oexpr:%lld, args:%s(%p)\n", res, args[0], &args[0]);
  	return res;
  }
  
  
  static number_t primary(enum token n)
  {
  #if TEST_DEBUG
  	number_t res = res; /* for compiler */
  #else
  	number_t res;
  #endif
  	const struct operator_t *args0_op;
  
  	nest_msg(">primary(%s)\n", TOKSTR[n]);
  	if (n == EOI) {
  		syntax(NULL, "argument expected");
  	}
  	if (n == LPAREN) {
  		res = oexpr(check_operator(*++args));
  		if (check_operator(*++args) != RPAREN)
  			syntax(NULL, "closing paren expected");
  		unnest_msg("<primary:%lld\n", res);
  		return res;
  	}
  
  	/* coreutils 6.9 checks "is args[1] binop and args[2] exist?" first,
  	 * do the same */
  	args0_op = last_operator;
  	/* last_operator = operator at args[1] */
  	if (check_operator(args[1]) != EOI) { /* if args[1] != NULL */
  		if (args[2]) {
  			// coreutils also does this:
  			// if (args[3] && args[0]="-l" && args[2] is BINOP)
  			//	return binop(1 /* prepended by -l */);
  			if (last_operator->op_type == BINOP)
  				unnest_msg_and_return(binop(), "<primary: binop:%lld\n");
  		}
  	}
  	/* check "is args[0] unop?" second */
  	if (args0_op->op_type == UNOP) {
  		/* unary expression */
  		if (args[1] == NULL)
  //			syntax(args0_op->op_text, "argument expected");
  			goto check_emptiness;
  		args++;
  		if (n == STREZ)
  			unnest_msg_and_return(args[0][0] == '\0', "<primary:%lld\n");
  		if (n == STRNZ)
  			unnest_msg_and_return(args[0][0] != '\0', "<primary:%lld\n");
  		if (n == FILTT)
  			unnest_msg_and_return(isatty(getn(*args)), "<primary: isatty(%s)%lld\n", *args);
  		unnest_msg_and_return(filstat(*args, n), "<primary: filstat(%s):%lld\n", *args);
  	}
  
  	/*check_operator(args[1]); - already done */
  	if (last_operator->op_type == BINOP) {
  		/* args[2] is known to be NULL, isn't it bound to fail? */
  		unnest_msg_and_return(binop(), "<primary:%lld\n");
  	}
   check_emptiness:
  	unnest_msg_and_return(args[0][0] != '\0', "<primary:%lld\n");
  }
  
  
  int test_main(int argc, char **argv)
  {
  	int res;
  	const char *arg0;
  
  	arg0 = bb_basename(argv[0]);
  	if ((ENABLE_TEST1 || ENABLE_TEST2 || ENABLE_ASH_TEST || ENABLE_HUSH_TEST)
  	 && (arg0[0] == '[')
  	) {
  		--argc;
  		if (!arg0[1]) { /* "[" ? */
  			if (NOT_LONE_CHAR(argv[argc], ']')) {
  				bb_error_msg("missing ]");
  				return 2;
  			}
  		} else { /* assuming "[[" */
  			if (strcmp(argv[argc], "]]") != 0) {
  				bb_error_msg("missing ]]");
  				return 2;
  			}
  		}
  		argv[argc] = NULL;
  	}
  	/* argc is unused after this point */
  
  	/* We must do DEINIT_S() prior to returning */
  	INIT_S();
  
  	res = setjmp(leaving);
  	if (res)
  		goto ret;
  
  	/* resetting ngroups is probably unnecessary.  it will
  	 * force a new call to getgroups(), which prevents using
  	 * group data fetched during a previous call.  but the
  	 * only way the group data could be stale is if there's
  	 * been an intervening call to setgroups(), and this
  	 * isn't likely in the case of a shell.  paranoia
  	 * prevails...
  	 */
  	/*ngroups = 0; - done by INIT_S() */
  
  	argv++;
  	args = argv;
  
  	/* Implement special cases from POSIX.2, section 4.62.4.
  	 * Testcase: "test '(' = '('"
  	 * The general parser would misinterpret '(' as group start.
  	 */
  	if (1) {
  		int negate = 0;
   again:
  		if (!argv[0]) {
  			/* "test" */
  			res = 1;
  			goto ret_special;
  		}
  		if (!argv[1]) {
  			/* "test [!] arg" */
  			res = (argv[0][0] == '\0');
  			goto ret_special;
  		}
  		if (argv[2]) {
  			if (!argv[3]) {
  				/*
  				 * http://pubs.opengroup.org/onlinepubs/009695399/utilities/test.html
  				 * """ 3 arguments:
  				 * If $2 is a binary primary, perform the binary test of $1 and $3.
  				 * """
  				 */
  				check_operator(argv[1]);
  				if (last_operator->op_type == BINOP) {
  					/* "test [!] arg1 <binary_op> arg2" */
  					args = argv;
  					res = (binop() == 0);
   ret_special:
  					/* If there was leading "!" op... */
  					res ^= negate;
  					goto ret;
  				}
  				/* """If $1 is '(' and $3 is ')', perform the unary test of $2."""
  				 * Looks like this works without additional coding.
  				 */
  				goto check_negate;
  			}
  			/* argv[3] exists (at least 4 args), is it exactly 4 args? */
  			if (!argv[4]) {
  				/*
  				 * """ 4 arguments:
  				 * If $1 is '!', negate the three-argument test of $2, $3, and $4.
  				 * If $1 is '(' and $4 is ')', perform the two-argument test of $2 and $3.
  				 * """
  				 * Example why code below is necessary: test '(' ! -e ')'
  				 */
  				if (LONE_CHAR(argv[0], '(')
  				 && LONE_CHAR(argv[3], ')')
  				) {
  					/* "test [!] ( x y )" */
  					argv[3] = NULL;
  					argv++;
  				}
  			}
  		}
   check_negate:
  		if (LONE_CHAR(argv[0], '!')) {
  			argv++;
  			negate ^= 1;
  			goto again;
  		}
  	}
  
  	res = !oexpr(check_operator(*args));
  
  	if (*args != NULL && *++args != NULL) {
  		/* Examples:
  		 * test 3 -lt 5 6
  		 * test -t 1 2
  		 */
  		bb_error_msg("%s: unknown operand", *args);
  		res = 2;
  	}
   ret:
  	DEINIT_S();
  	return res;
  }
  