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586 lines
11 KiB
C
586 lines
11 KiB
C
/* vi: set sw=4 ts=4: */
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/*
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* test implementation for busybox
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*
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* Copyright (c) by a whole pile of folks:
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*
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* test(1); version 7-like -- author Erik Baalbergen
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* modified by Eric Gisin to be used as built-in.
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* modified by Arnold Robbins to add SVR3 compatibility
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* (-x -c -b -p -u -g -k) plus Korn's -L -nt -ot -ef and new -S (socket).
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* modified by J.T. Conklin for NetBSD.
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* modified by Herbert Xu to be used as built-in in ash.
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* modified by Erik Andersen <andersen@codepoet.org> to be used
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* in busybox.
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*
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* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
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*
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* Original copyright notice states:
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* "This program is in the Public Domain."
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*/
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#include "busybox.h"
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#include <unistd.h>
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#include <ctype.h>
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#include <errno.h>
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#include <string.h>
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#include <setjmp.h>
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/* test(1) accepts the following grammar:
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oexpr ::= aexpr | aexpr "-o" oexpr ;
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aexpr ::= nexpr | nexpr "-a" aexpr ;
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nexpr ::= primary | "!" primary
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primary ::= unary-operator operand
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| operand binary-operator operand
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| operand
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| "(" oexpr ")"
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;
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unary-operator ::= "-r"|"-w"|"-x"|"-f"|"-d"|"-c"|"-b"|"-p"|
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"-u"|"-g"|"-k"|"-s"|"-t"|"-z"|"-n"|"-o"|"-O"|"-G"|"-L"|"-S";
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binary-operator ::= "="|"=="|"!="|"-eq"|"-ne"|"-ge"|"-gt"|"-le"|"-lt"|
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"-nt"|"-ot"|"-ef";
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operand ::= <any legal UNIX file name>
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*/
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enum token {
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EOI,
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FILRD,
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FILWR,
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FILEX,
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FILEXIST,
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FILREG,
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FILDIR,
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FILCDEV,
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FILBDEV,
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FILFIFO,
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FILSOCK,
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FILSYM,
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FILGZ,
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FILTT,
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FILSUID,
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FILSGID,
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FILSTCK,
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FILNT,
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FILOT,
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FILEQ,
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FILUID,
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FILGID,
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STREZ,
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STRNZ,
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STREQ,
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STRNE,
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STRLT,
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STRGT,
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INTEQ,
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INTNE,
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INTGE,
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INTGT,
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INTLE,
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INTLT,
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UNOT,
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BAND,
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BOR,
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LPAREN,
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RPAREN,
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OPERAND
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};
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enum token_types {
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UNOP,
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BINOP,
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BUNOP,
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BBINOP,
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PAREN
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};
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static const struct t_op {
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const char *op_text;
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short op_num, op_type;
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} ops[] = {
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{
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"-r", FILRD, UNOP}, {
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"-w", FILWR, UNOP}, {
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"-x", FILEX, UNOP}, {
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"-e", FILEXIST, UNOP}, {
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"-f", FILREG, UNOP}, {
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"-d", FILDIR, UNOP}, {
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"-c", FILCDEV, UNOP}, {
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"-b", FILBDEV, UNOP}, {
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"-p", FILFIFO, UNOP}, {
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"-u", FILSUID, UNOP}, {
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"-g", FILSGID, UNOP}, {
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"-k", FILSTCK, UNOP}, {
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"-s", FILGZ, UNOP}, {
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"-t", FILTT, UNOP}, {
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"-z", STREZ, UNOP}, {
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"-n", STRNZ, UNOP}, {
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"-h", FILSYM, UNOP}, /* for backwards compat */
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{
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"-O", FILUID, UNOP}, {
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"-G", FILGID, UNOP}, {
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"-L", FILSYM, UNOP}, {
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"-S", FILSOCK, UNOP}, {
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"=", STREQ, BINOP}, {
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"==", STREQ, BINOP}, {
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"!=", STRNE, BINOP}, {
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"<", STRLT, BINOP}, {
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">", STRGT, BINOP}, {
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"-eq", INTEQ, BINOP}, {
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"-ne", INTNE, BINOP}, {
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"-ge", INTGE, BINOP}, {
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"-gt", INTGT, BINOP}, {
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"-le", INTLE, BINOP}, {
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"-lt", INTLT, BINOP}, {
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"-nt", FILNT, BINOP}, {
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"-ot", FILOT, BINOP}, {
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"-ef", FILEQ, BINOP}, {
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"!", UNOT, BUNOP}, {
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"-a", BAND, BBINOP}, {
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"-o", BOR, BBINOP}, {
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"(", LPAREN, PAREN}, {
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")", RPAREN, PAREN}, {
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0, 0, 0}
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};
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#ifdef CONFIG_FEATURE_TEST_64
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typedef int64_t arith_t;
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#else
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typedef int arith_t;
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#endif
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static char **t_wp;
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static struct t_op const *t_wp_op;
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static gid_t *group_array;
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static int ngroups;
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static enum token t_lex(char *s);
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static arith_t oexpr(enum token n);
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static arith_t aexpr(enum token n);
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static arith_t nexpr(enum token n);
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static int binop(void);
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static arith_t primary(enum token n);
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static int filstat(char *nm, enum token mode);
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static arith_t getn(const char *s);
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static int newerf(const char *f1, const char *f2);
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static int olderf(const char *f1, const char *f2);
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static int equalf(const char *f1, const char *f2);
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static int test_eaccess(char *path, int mode);
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static int is_a_group_member(gid_t gid);
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static void initialize_group_array(void);
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static jmp_buf leaving;
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int bb_test(int argc, char **argv)
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{
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int res;
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if (LONE_CHAR(argv[0], '[')) {
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--argc;
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if (NOT_LONE_CHAR(argv[argc], ']')) {
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bb_error_msg("missing ]");
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return 2;
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}
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argv[argc] = NULL;
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} else if (strcmp(argv[0], "[[") == 0) {
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--argc;
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if (strcmp(argv[argc], "]]")) {
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bb_error_msg("missing ]]");
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return 2;
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}
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argv[argc] = NULL;
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}
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res = setjmp(leaving);
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if (res)
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return res;
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/* resetting ngroups is probably unnecessary. it will
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* force a new call to getgroups(), which prevents using
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* group data fetched during a previous call. but the
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* only way the group data could be stale is if there's
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* been an intervening call to setgroups(), and this
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* isn't likely in the case of a shell. paranoia
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* prevails...
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*/
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ngroups = 0;
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/* Implement special cases from POSIX.2, section 4.62.4 */
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switch (argc) {
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case 1:
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return 1;
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case 2:
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return *argv[1] == '\0';
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case 3:
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if (argv[1][0] == '!' && argv[1][1] == '\0') {
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return *argv[2] != '\0';
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}
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break;
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case 4:
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if (argv[1][0] != '!' || argv[1][1] != '\0') {
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if (t_lex(argv[2]), t_wp_op && t_wp_op->op_type == BINOP) {
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t_wp = &argv[1];
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return binop() == 0;
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}
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}
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break;
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case 5:
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if (argv[1][0] == '!' && argv[1][1] == '\0') {
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if (t_lex(argv[3]), t_wp_op && t_wp_op->op_type == BINOP) {
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t_wp = &argv[2];
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return binop() != 0;
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}
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}
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break;
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}
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t_wp = &argv[1];
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res = !oexpr(t_lex(*t_wp));
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if (*t_wp != NULL && *++t_wp != NULL) {
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bb_error_msg("%s: unknown operand", *t_wp);
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return 2;
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}
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return res;
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}
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static void syntax(const char *op, const char *msg)
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{
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if (op && *op) {
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bb_error_msg("%s: %s", op, msg);
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} else {
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bb_error_msg("%s", msg);
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}
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longjmp(leaving, 2);
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}
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static arith_t oexpr(enum token n)
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{
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arith_t res;
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res = aexpr(n);
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if (t_lex(*++t_wp) == BOR) {
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return oexpr(t_lex(*++t_wp)) || res;
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}
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t_wp--;
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return res;
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}
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static arith_t aexpr(enum token n)
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{
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arith_t res;
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res = nexpr(n);
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if (t_lex(*++t_wp) == BAND)
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return aexpr(t_lex(*++t_wp)) && res;
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t_wp--;
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return res;
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}
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static arith_t nexpr(enum token n)
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{
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if (n == UNOT)
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return !nexpr(t_lex(*++t_wp));
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return primary(n);
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}
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static arith_t primary(enum token n)
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{
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arith_t res;
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if (n == EOI) {
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syntax(NULL, "argument expected");
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}
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if (n == LPAREN) {
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res = oexpr(t_lex(*++t_wp));
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if (t_lex(*++t_wp) != RPAREN)
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syntax(NULL, "closing paren expected");
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return res;
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}
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if (t_wp_op && t_wp_op->op_type == UNOP) {
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/* unary expression */
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if (*++t_wp == NULL)
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syntax(t_wp_op->op_text, "argument expected");
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switch (n) {
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case STREZ:
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return strlen(*t_wp) == 0;
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case STRNZ:
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return strlen(*t_wp) != 0;
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case FILTT:
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return isatty(getn(*t_wp));
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default:
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return filstat(*t_wp, n);
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}
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}
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if (t_lex(t_wp[1]), t_wp_op && t_wp_op->op_type == BINOP) {
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return binop();
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}
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return strlen(*t_wp) > 0;
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}
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static int binop(void)
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{
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const char *opnd1, *opnd2;
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struct t_op const *op;
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opnd1 = *t_wp;
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(void) t_lex(*++t_wp);
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op = t_wp_op;
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if ((opnd2 = *++t_wp) == (char *) 0)
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syntax(op->op_text, "argument expected");
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switch (op->op_num) {
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case STREQ:
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return strcmp(opnd1, opnd2) == 0;
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case STRNE:
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return strcmp(opnd1, opnd2) != 0;
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case STRLT:
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return strcmp(opnd1, opnd2) < 0;
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case STRGT:
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return strcmp(opnd1, opnd2) > 0;
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case INTEQ:
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return getn(opnd1) == getn(opnd2);
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case INTNE:
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return getn(opnd1) != getn(opnd2);
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case INTGE:
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return getn(opnd1) >= getn(opnd2);
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case INTGT:
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return getn(opnd1) > getn(opnd2);
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case INTLE:
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return getn(opnd1) <= getn(opnd2);
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case INTLT:
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return getn(opnd1) < getn(opnd2);
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case FILNT:
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return newerf(opnd1, opnd2);
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case FILOT:
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return olderf(opnd1, opnd2);
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case FILEQ:
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return equalf(opnd1, opnd2);
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}
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/* NOTREACHED */
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return 1;
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}
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static int filstat(char *nm, enum token mode)
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{
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struct stat s;
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unsigned int i;
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if (mode == FILSYM) {
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#ifdef S_IFLNK
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if (lstat(nm, &s) == 0) {
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i = S_IFLNK;
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goto filetype;
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}
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#endif
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return 0;
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}
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if (stat(nm, &s) != 0)
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return 0;
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switch (mode) {
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case FILRD:
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return test_eaccess(nm, R_OK) == 0;
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case FILWR:
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return test_eaccess(nm, W_OK) == 0;
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case FILEX:
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return test_eaccess(nm, X_OK) == 0;
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case FILEXIST:
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return 1;
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case FILREG:
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i = S_IFREG;
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goto filetype;
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case FILDIR:
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i = S_IFDIR;
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goto filetype;
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case FILCDEV:
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i = S_IFCHR;
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goto filetype;
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case FILBDEV:
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i = S_IFBLK;
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goto filetype;
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case FILFIFO:
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#ifdef S_IFIFO
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i = S_IFIFO;
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goto filetype;
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#else
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return 0;
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#endif
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case FILSOCK:
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#ifdef S_IFSOCK
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i = S_IFSOCK;
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goto filetype;
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#else
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return 0;
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#endif
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case FILSUID:
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i = S_ISUID;
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goto filebit;
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case FILSGID:
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i = S_ISGID;
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goto filebit;
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case FILSTCK:
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i = S_ISVTX;
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goto filebit;
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case FILGZ:
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return s.st_size > 0L;
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case FILUID:
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return s.st_uid == geteuid();
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case FILGID:
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return s.st_gid == getegid();
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default:
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return 1;
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}
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filetype:
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return ((s.st_mode & S_IFMT) == i);
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filebit:
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return ((s.st_mode & i) != 0);
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}
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static enum token t_lex(char *s)
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{
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struct t_op const *op = ops;
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if (s == 0) {
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t_wp_op = (struct t_op *) 0;
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return EOI;
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}
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while (op->op_text) {
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if (strcmp(s, op->op_text) == 0) {
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t_wp_op = op;
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return op->op_num;
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}
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op++;
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}
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t_wp_op = (struct t_op *) 0;
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return OPERAND;
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}
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/* atoi with error detection */
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static arith_t getn(const char *s)
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{
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char *p;
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#ifdef CONFIG_FEATURE_TEST_64
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long long r;
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#else
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long r;
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#endif
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errno = 0;
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#ifdef CONFIG_FEATURE_TEST_64
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r = strtoll(s, &p, 10);
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#else
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r = strtol(s, &p, 10);
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#endif
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if (errno != 0)
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syntax(s, "out of range");
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if (*(skip_whitespace(p)))
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syntax(s, "bad number");
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return r;
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}
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static int newerf(const char *f1, const char *f2)
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{
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struct stat b1, b2;
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return (stat(f1, &b1) == 0 &&
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stat(f2, &b2) == 0 && b1.st_mtime > b2.st_mtime);
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}
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static int olderf(const char *f1, const char *f2)
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{
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struct stat b1, b2;
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return (stat(f1, &b1) == 0 &&
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stat(f2, &b2) == 0 && b1.st_mtime < b2.st_mtime);
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}
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static int equalf(const char *f1, const char *f2)
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{
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struct stat b1, b2;
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return (stat(f1, &b1) == 0 &&
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stat(f2, &b2) == 0 &&
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b1.st_dev == b2.st_dev && b1.st_ino == b2.st_ino);
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}
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/* Do the same thing access(2) does, but use the effective uid and gid,
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and don't make the mistake of telling root that any file is
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executable. */
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static int test_eaccess(char *path, int mode)
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{
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struct stat st;
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unsigned int euid = geteuid();
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if (stat(path, &st) < 0)
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return -1;
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if (euid == 0) {
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/* Root can read or write any file. */
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if (mode != X_OK)
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return 0;
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/* Root can execute any file that has any one of the execute
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bits set. */
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if (st.st_mode & (S_IXUSR | S_IXGRP | S_IXOTH))
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return 0;
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}
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if (st.st_uid == euid) /* owner */
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mode <<= 6;
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else if (is_a_group_member(st.st_gid))
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mode <<= 3;
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if (st.st_mode & mode)
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return 0;
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return -1;
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}
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static void initialize_group_array(void)
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{
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ngroups = getgroups(0, NULL);
|
|
if (ngroups > 0) {
|
|
group_array = xmalloc(ngroups * sizeof(gid_t));
|
|
getgroups(ngroups, group_array);
|
|
}
|
|
}
|
|
|
|
/* Return non-zero if GID is one that we have in our groups list. */
|
|
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;
|
|
}
|
|
|
|
|
|
/* applet entry point */
|
|
|
|
int test_main(int argc, char **argv)
|
|
{
|
|
return bb_test(argc, argv);
|
|
}
|
|
|