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/*
 * 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 Michael Rendell to add Korn's [[ .. ]] expressions.
 * modified by J.T. Conklin to add POSIX compatibility.
 */

#include "sh.h"
#include "ksh_stat.h"
#include "c_test.h"

/* test(1) accepts the following grammar:
        oexpr   ::= aexpr | aexpr "-o" oexpr ;
        aexpr   ::= nexpr | nexpr "-a" aexpr ;
        nexpr   ::= primary | "!" nexpr ;
        primary ::= unary-operator operand
                | operand binary-operator operand
                | operand
                | "(" oexpr ")"
                ;

        unary-operator ::= "-a"|"-r"|"-w"|"-x"|"-e"|"-f"|"-d"|"-c"|"-b"|"-p"|
                           "-u"|"-g"|"-k"|"-s"|"-t"|"-z"|"-n"|"-o"|"-O"|"-G"|
                           "-L"|"-h"|"-S"|"-H";

        binary-operator ::= "="|"=="|"!="|"-eq"|"-ne"|"-ge"|"-gt"|"-le"|"-lt"|
                            "-nt"|"-ot"|"-ef"|
                            "<"|">"     # rules used for [[ .. ]] expressions
                            ;
        operand ::= <any thing>
*/

#define T_ERR_EXIT      2       /* POSIX says > 1 for errors */

struct t_op {
        char    op_text[4];
        Test_op op_num;
};
static const struct t_op u_ops [] = {
        {"-a",  TO_FILAXST },
        {"-b",  TO_FILBDEV },
        {"-c",  TO_FILCDEV },
        {"-d",  TO_FILID },
        {"-e",  TO_FILEXST },
        {"-f",  TO_FILREG },
        {"-G",  TO_FILGID },
        {"-g",  TO_FILSETG },
        {"-h",  TO_FILSYM },
        {"-H",  TO_FILCDF },
        {"-k",  TO_FILSTCK },
        {"-L",  TO_FILSYM },
        {"-n",  TO_STNZE },
        {"-O",  TO_FILUID },
        {"-o",  TO_OPTION },
        {"-p",  TO_FILFIFO },
        {"-r",  TO_FILRD },
        {"-s",  TO_FILGZ },
        {"-S",  TO_FILSOCK },
        {"-t",  TO_FILTT },
        {"-u",  TO_FILSETU },
        {"-w",  TO_FILWR },
        {"-x",  TO_FILEX },
        {"-z",  TO_STZER },
        {"",    TO_NONOP }
    };
static const struct t_op b_ops [] = {
        {"=",   TO_STEQL },
#ifdef KSH
        {"==",  TO_STEQL },
#endif /* KSH */
        {"!=",  TO_STNEQ },
        {"<",   TO_STLT },
        {">",   TO_STGT },
        {"-eq", TO_INTEQ },
        {"-ne", TO_INTNE },
        {"-gt", TO_INTGT },
        {"-ge", TO_INTGE },
        {"-lt", TO_INTLT },
        {"-le", TO_INTLE },
        {"-ef", TO_FILEQ },
        {"-nt", TO_FILNT },
        {"-ot", TO_FILOT },
        {"",    TO_NONOP }
    };

static int      test_stat ARGS((const char *path, struct stat *statb));
static int      test_eaccess ARGS((const char *path, int mode));
static int      test_oexpr ARGS((Test_env *te, int do_eval));
static int      test_aexpr ARGS((Test_env *te, int do_eval));
static int      test_nexpr ARGS((Test_env *te, int do_eval));
static int      test_primary ARGS((Test_env *te, int do_eval));
static int      ptest_isa ARGS((Test_env *te, Test_meta meta));
static const char *ptest_getopnd ARGS((Test_env *te, Test_op op, int do_eval));
static int      ptest_eval ARGS((Test_env *te, Test_op op, const char *opnd1,
                                const char *opnd2, int do_eval));
static void     ptest_error ARGS((Test_env *te, int offset, const char *msg));

int
c_test(wp)
        char **wp;
{
        int argc;
        int res;
        Test_env te;

        te.flags = 0;
        te.isa = ptest_isa;
        te.getopnd = ptest_getopnd;
        te.eval = ptest_eval;
        te.error = ptest_error;

        for (argc = 0; wp[argc]; argc++)
                ;

        if (strcmp(wp[0], "[") == 0) {
                if (strcmp(wp[--argc], "]") != 0) {
                        bi_errorf("missing ]");
                        return T_ERR_EXIT;
                }
        }

        te.pos.wp = wp + 1;
        te.wp_end = wp + argc;

        /* 
         * Handle the special cases from POSIX.2, section 4.62.4.
         * Implementation of all the rules isn't necessary since 
         * our parser does the right thing for the ommited steps.
         */
        if (argc <= 5) {
                char **owp = wp;
                int invert = 0;
                Test_op op;
                const char *opnd1, *opnd2;

                while (--argc >= 0) {
                        if ((*te.isa)(&te, TM_END))
                                return !0;
                        if (argc == 3) {
                                opnd1 = (*te.getopnd)(&te, TO_NONOP, 1);
                                if ((op = (Test_op) (*te.isa)(&te, TM_BINOP))) {
                                        opnd2 = (*te.getopnd)(&te, op, 1);
                                        res = (*te.eval)(&te, op, opnd1, opnd2,
                                                        1);
                                        if (te.flags & TEF_ERROR)
                                                return T_ERR_EXIT;
                                        if (invert & 1)
                                                res = !res;
                                        return !res;
                                }
                                /* back up to opnd1 */
                                te.pos.wp--;
                        }
                        if (argc == 1) {
                                opnd1 = (*te.getopnd)(&te, TO_NONOP, 1);
                                /* Historically, -t by itself test if fd 1
                                 * is a file descriptor, but POSIX says its
                                 * a string test...
                                 */
                                if (!Flag(FPOSIX) && strcmp(opnd1, "-t") == 0)
                                    break;
                                res = (*te.eval)(&te, TO_STNZE, opnd1,
                                                (char *) 0, 1);
                                if (invert & 1)
                                        res = !res;
                                return !res;
                        }
                        if ((*te.isa)(&te, TM_NOT)) {
                                invert++;
                        } else
                                break;
                }
                te.pos.wp = owp + 1;
        }

        return test_parse(&te);
}

/*
 * Generic test routines.
 */

Test_op
test_isop(te, meta, s)
        Test_env *te;
        Test_meta meta;
        const char *s;
{
        char sc1;
        const struct t_op *otab;

        otab = meta == TM_UNOP ? u_ops : b_ops;
        if (*s) {
                sc1 = s[1];
                for (; otab->op_text[0]; otab++)
                        if (sc1 == otab->op_text[1]
                            && strcmp(s, otab->op_text) == 0
                            && ((te->flags & TEF_DBRACKET)
                                || (otab->op_num != TO_STLT
                                    && otab->op_num != TO_STGT)))
                                return otab->op_num;
        }
        return TO_NONOP;
}

int
test_eval(te, op, opnd1, opnd2, do_eval)
        Test_env *te;
        Test_op op;
        const char *opnd1;
        const char *opnd2;
        int do_eval;
{
        int res;
        int not;
        struct stat b1, b2;

        if (!do_eval)
                return 0;

        switch ((int) op) {
        /*
         * Unary Operators
         */
          case TO_STNZE: /* -n */
                return *opnd1 != '\0';
          case TO_STZER: /* -z */
                return *opnd1 == '\0';
          case TO_OPTION: /* -o */
                if ((not = *opnd1 == '!'))
                        opnd1++;
                if ((res = option(opnd1)) < 0)
                        res = 0;
                else {
                        res = Flag(res);
                        if (not)
                                res = !res;
                }
                return res; 
          case TO_FILRD: /* -r */
                return test_eaccess(opnd1, R_OK) == 0;
          case TO_FILWR: /* -w */
                return test_eaccess(opnd1, W_OK) == 0;
          case TO_FILEX: /* -x */
                return test_eaccess(opnd1, X_OK) == 0;
          case TO_FILAXST: /* -a */
                return test_stat(opnd1, &b1) == 0;
          case TO_FILEXST: /* -e */
                /* at&t ksh does not appear to do the /dev/fd/ thing for
                 * this (unless the os itself handles it)
                 */
                return stat(opnd1, &b1) == 0;
          case TO_FILREG: /* -r */
                return test_stat(opnd1, &b1) == 0 && S_ISREG(b1.st_mode);
          case TO_FILID: /* -d */
                return test_stat(opnd1, &b1) == 0 && S_ISDIR(b1.st_mode);
          case TO_FILCDEV: /* -c */
#ifdef S_ISCHR
                return test_stat(opnd1, &b1) == 0 && S_ISCHR(b1.st_mode);
#else
                return 0;
#endif
          case TO_FILBDEV: /* -b */
#ifdef S_ISBLK
                return test_stat(opnd1, &b1) == 0 && S_ISBLK(b1.st_mode);
#else
                return 0;
#endif
          case TO_FILFIFO: /* -p */
#ifdef S_ISFIFO
                return test_stat(opnd1, &b1) == 0 && S_ISFIFO(b1.st_mode);
#else
                return 0;
#endif
          case TO_FILSYM: /* -h -L */
#ifdef S_ISLNK
                return lstat(opnd1, &b1) == 0 && S_ISLNK(b1.st_mode);
#else
                return 0;
#endif
          case TO_FILSOCK: /* -S */
#ifdef S_ISSOCK
                return test_stat(opnd1, &b1) == 0 && S_ISSOCK(b1.st_mode);
#else
                return 0;
#endif
          case TO_FILCDF:/* -H HP context dependent files (directories) */
#ifdef S_ISCDF
          {
                /* Append a + to filename and check to see if result is a
                 * setuid directory.  CDF stuff in general is hookey, since
                 * it breaks for the following sequence: echo hi > foo+;
                 * mkdir foo; echo bye > foo/default; chmod u+s foo
                 * (foo+ refers to the file with hi in it, there is no way
                 * to get at the file with bye in it - please correct me if
                 * I'm wrong about this).
                 */
                int len = strlen(opnd1);
                char *p = str_nsave(opnd1, len + 1, ATEMP);

                p[len++] = '+';
                p[len] = '\0';
                return stat(p, &b1) == 0 && S_ISCDF(b1.st_mode);
          }
#else
                return 0;
#endif
          case TO_FILSETU: /* -u */
#ifdef S_ISUID
                return test_stat(opnd1, &b1) == 0
                        && (b1.st_mode & S_ISUID) == S_ISUID;
#else
                return 0;
#endif
          case TO_FILSETG: /* -g */
#ifdef S_ISGID
                return test_stat(opnd1, &b1) == 0
                        && (b1.st_mode & S_ISGID) == S_ISGID;
#else
                return 0;
#endif
          case TO_FILSTCK: /* -k */
                return test_stat(opnd1, &b1) == 0
                        && (b1.st_mode & S_ISVTX) == S_ISVTX;
          case TO_FILGZ: /* -s */
                return test_stat(opnd1, &b1) == 0 && b1.st_size > 0L;
          case TO_FILTT: /* -t */
                if (opnd1 && !bi_getn(opnd1, &res)) {
                        te->flags |= TEF_ERROR;
                        res = 0;
                } else {
                        /* generate error if in FPOSIX mode? */
                        res = isatty(opnd1 ? res : 0);
                }
                return res;
          case TO_FILUID: /* -O */
                return test_stat(opnd1, &b1) == 0 && b1.st_uid == ksheuid;
          case TO_FILGID: /* -G */
                return test_stat(opnd1, &b1) == 0 && b1.st_gid == getegid();
        /*
         * Binary Operators
         */
          case TO_STEQL: /* = */
                if (te->flags & TEF_DBRACKET)
                        return gmatch(opnd1, opnd2, FALSE);
                return strcmp(opnd1, opnd2) == 0;
          case TO_STNEQ: /* != */
                if (te->flags & TEF_DBRACKET)
                        return !gmatch(opnd1, opnd2, FALSE);
                return strcmp(opnd1, opnd2) != 0;
          case TO_STLT: /* < */
                return strcmp(opnd1, opnd2) < 0;
          case TO_STGT: /* > */
                return strcmp(opnd1, opnd2) > 0;
          case TO_INTEQ: /* -eq */
          case TO_INTNE: /* -ne */
          case TO_INTGE: /* -ge */
          case TO_INTGT: /* -gt */
          case TO_INTLE: /* -le */
          case TO_INTLT: /* -lt */
                {
                        long v1, v2;

                        if (!evaluate(opnd1, &v1, KSH_RETURN_ERROR)
                            || !evaluate(opnd2, &v2, KSH_RETURN_ERROR))
                        {
                                /* error already printed.. */
                                te->flags |= TEF_ERROR;
                                return 1;
                        }
                        switch ((int) op) {
                          case TO_INTEQ:
                                return v1 == v2;
                          case TO_INTNE:
                                return v1 != v2;
                          case TO_INTGE:
                                return v1 >= v2;
                          case TO_INTGT:
                                return v1 > v2;
                          case TO_INTLE:
                                return v1 <= v2;
                          case TO_INTLT:
                                return v1 < v2;
                        }
                }
          case TO_FILNT: /* -nt */
                {
                        int s2;
                        /* ksh88/ksh93 succeed if file2 can't be stated
                         * (subtly different from `does not exist').
                         */
                        return stat(opnd1, &b1) == 0
                                && (((s2 = stat(opnd2, &b2)) == 0
                                      && b1.st_mtime > b2.st_mtime) || s2 < 0);
                }
          case TO_FILOT: /* -ot */
                {
                        int s1;
                        /* ksh88/ksh93 succeed if file1 can't be stated
                         * (subtly different from `does not exist').
                         */
                        return stat(opnd2, &b2) == 0
                                && (((s1 = stat(opnd1, &b1)) == 0
                                      && b1.st_mtime < b2.st_mtime) || s1 < 0);
                }
          case TO_FILEQ: /* -ef */
                return stat (opnd1, &b1) == 0 && stat (opnd2, &b2) == 0
                       && b1.st_dev == b2.st_dev
                       && b1.st_ino == b2.st_ino;
        }
        (*te->error)(te, 0, "internal error: unknown op");
        return 1;
}

/* Nasty kludge to handle Korn's bizarre /dev/fd hack */
static int
test_stat(path, statb)
        const char *path;
        struct stat *statb;
{
#if !defined(HAVE_DEV_FD)
        int fd;

        if (strncmp(path, "/dev/fd/", 8) == 0 && getn(path + 8, &fd))
                return fstat(fd, statb);
#endif /* !HAVE_DEV_FD */

        return stat(path, statb);
}

/* Routine to handle Korn's /dev/fd hack, and to deal with X_OK on
 * non-directories when running as root.
 */
static int
test_eaccess(path, mode)
        const char *path;
        int mode;
{
        int res;

#if !defined(HAVE_DEV_FD)
        int fd;

        /* Note: doesn't handle //dev/fd, etc.. (this is ok) */
        if (strncmp(path, "/dev/fd/", 8) == 0 && getn(path + 8, &fd)) {
                int flags;

                if ((flags = fcntl(fd, F_GETFL, 0)) < 0
                    || (mode & X_OK)
                    || ((mode & W_OK) && (flags & O_ACCMODE) == O_RDONLY)
                    || ((mode & R_OK) && (flags & O_ACCMODE) == O_WRONLY))
                        return -1;
                return 0;
        }
#endif /* !HAVE_DEV_FD */

        /* On most (all?) unixes, access() says everything is executable for
         * root - avoid this on files by using stat().
         */
        if ((mode & X_OK) && ksheuid == 0) {
                struct stat statb;

                if (stat(path, &statb) < 0)
                        res = -1;
                else if (S_ISDIR(statb.st_mode))
                        res = 0;
                else
                        res = (statb.st_mode & (S_IXUSR|S_IXGRP|S_IXOTH))
                                ? 0 : -1;
                /* Need to check other permissions?  If so, use access() as
                 * this will deal with root on NFS.
                 */
                if (res == 0 && (mode & (R_OK|W_OK)))
                        res = eaccess(path, mode);
        } else
                res = eaccess(path, mode);

        return res;
}

int
test_parse(te)
        Test_env *te;
{
        int res;

        res = test_oexpr(te, 1);

        if (!(te->flags & TEF_ERROR) && !(*te->isa)(te, TM_END))
                (*te->error)(te, 0, "unexpected operator/operand");

        return (te->flags & TEF_ERROR) ? T_ERR_EXIT : !res;
}

static int
test_oexpr(te, do_eval)
        Test_env *te;
        int do_eval;
{
        int res;

        res = test_aexpr(te, do_eval);
        if (res)
                do_eval = 0;
        if (!(te->flags & TEF_ERROR) && (*te->isa)(te, TM_OR))
                return test_oexpr(te, do_eval) || res;
        return res;
}

static int
test_aexpr(te, do_eval)
        Test_env *te;
        int do_eval;
{
        int res;

        res = test_nexpr(te, do_eval);
        if (!res)
                do_eval = 0;
        if (!(te->flags & TEF_ERROR) && (*te->isa)(te, TM_AND))
                return test_aexpr(te, do_eval) && res;
        return res;
}

static int
test_nexpr(te, do_eval)
        Test_env *te;
        int do_eval;
{
        if (!(te->flags & TEF_ERROR) && (*te->isa)(te, TM_NOT))
                return !test_nexpr(te, do_eval);
        return test_primary(te, do_eval);
}

static int
test_primary(te, do_eval)
        Test_env *te;
        int do_eval;
{
        const char *opnd1, *opnd2;
        int res;
        Test_op op;

        if (te->flags & TEF_ERROR)
                return 0;
        if ((*te->isa)(te, TM_OPAREN)) {
                res = test_oexpr(te, do_eval);
                if (te->flags & TEF_ERROR)
                        return 0;
                if (!(*te->isa)(te, TM_CPAREN)) {
                        (*te->error)(te, 0, "missing closing paren");
                        return 0;
                }
                return res;
        }
        if ((op = (Test_op) (*te->isa)(te, TM_UNOP))) {
                /* unary expression */
                opnd1 = (*te->getopnd)(te, op, do_eval);
                if (!opnd1) {
                        (*te->error)(te, -1, "missing argument");
                        return 0;
                }

                return (*te->eval)(te, op, opnd1, (const char *) 0, do_eval);
        }
        opnd1 = (*te->getopnd)(te, TO_NONOP, do_eval);
        if (!opnd1) {
                (*te->error)(te, 0, "expression expected");
                return 0;
        }
        if ((op = (Test_op) (*te->isa)(te, TM_BINOP))) {
                /* binary expression */
                opnd2 = (*te->getopnd)(te, op, do_eval);
                if (!opnd2) {
                        (*te->error)(te, -1, "missing second argument");
                        return 0;
                }

                return (*te->eval)(te, op, opnd1, opnd2, do_eval);
        }
        if (te->flags & TEF_DBRACKET) {
                (*te->error)(te, -1, "missing expression operator");
                return 0;
        }
        return (*te->eval)(te, TO_STNZE, opnd1, (const char *) 0, do_eval);
}

/*
 * Plain test (test and [ .. ]) specific routines.
 */

/* Test if the current token is a whatever.  Accepts the current token if
 * it is.  Returns 0 if it is not, non-zero if it is (in the case of
 * TM_UNOP and TM_BINOP, the returned value is a Test_op).
 */
static int
ptest_isa(te, meta)
        Test_env *te;
        Test_meta meta;
{
        /* Order important - indexed by Test_meta values */
        static const char *const tokens[] = {
                                "-o", "-a", "!", "(", ")"
                        };
        int ret;

        if (te->pos.wp >= te->wp_end)
                return meta == TM_END;

        if (meta == TM_UNOP || meta == TM_BINOP)
                ret = (int) test_isop(te, meta, *te->pos.wp);
        else if (meta == TM_END)
                ret = 0;
        else
                ret = strcmp(*te->pos.wp, tokens[(int) meta]) == 0;

        /* Accept the token? */
        if (ret)
                te->pos.wp++;

        return ret;
}

static const char *
ptest_getopnd(te, op, do_eval)
        Test_env *te;
        Test_op op;
        int do_eval;
{
        if (te->pos.wp >= te->wp_end)
                return op == TO_FILTT ? "1" : (const char *) 0;
        return *te->pos.wp++;
}

static int
ptest_eval(te, op, opnd1, opnd2, do_eval)
        Test_env *te;
        Test_op op;
        const char *opnd1;
        const char *opnd2;
        int do_eval;
{
        return test_eval(te, op, opnd1, opnd2, do_eval);
}

static void
ptest_error(te, offset, msg)
        Test_env *te;
        int offset;
        const char *msg;
{
        const char *op = te->pos.wp + offset >= te->wp_end ?
                                (const char *) 0 : te->pos.wp[offset];

        te->flags |= TEF_ERROR;
        if (op)
                bi_errorf("%s: %s", op, msg);
        else
                bi_errorf("%s", msg);
}