/*      $OpenBSD: c_test.c,v 1.29 2025/03/24 22:19:42 millert Exp $     */

/*
 * 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 <sys/stat.h>

#include <string.h>
#include <unistd.h>

#include "sh.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"|"<"|">"
                            ;
        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 },
        {"==",  TO_STEQL },
        {"!=",  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_eaccess(const char *, int);
static int      test_oexpr(Test_env *, int);
static int      test_aexpr(Test_env *, int);
static int      test_nexpr(Test_env *, int);
static int      test_primary(Test_env *, int);
static int      ptest_isa(Test_env *, Test_meta);
static const char *ptest_getopnd(Test_env *, Test_op, int);
static int      ptest_eval(Test_env *, Test_op, const char *,
                    const char *, int);
static void     ptest_error(Test_env *, int, const char *);

int
c_test(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 omitted 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);
                                res = (*te.eval)(&te, TO_STNZE, opnd1,
                                    NULL, 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(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)
                                return otab->op_num;
        }
        return TO_NONOP;
}

int
test_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 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 stat(opnd1, &b1) == 0 && S_ISREG(b1.st_mode);
        case TO_FILID: /* -d */
                return stat(opnd1, &b1) == 0 && S_ISDIR(b1.st_mode);
        case TO_FILCDEV: /* -c */
                return stat(opnd1, &b1) == 0 && S_ISCHR(b1.st_mode);
        case TO_FILBDEV: /* -b */
                return stat(opnd1, &b1) == 0 && S_ISBLK(b1.st_mode);
        case TO_FILFIFO: /* -p */
                return stat(opnd1, &b1) == 0 && S_ISFIFO(b1.st_mode);
        case TO_FILSYM: /* -h -L */
                return lstat(opnd1, &b1) == 0 && S_ISLNK(b1.st_mode);
        case TO_FILSOCK: /* -S */
                return stat(opnd1, &b1) == 0 && S_ISSOCK(b1.st_mode);
        case TO_FILCDF:/* -H HP context dependent files (directories) */
                return 0;
        case TO_FILSETU: /* -u */
                return stat(opnd1, &b1) == 0 &&
                    (b1.st_mode & S_ISUID) == S_ISUID;
        case TO_FILSETG: /* -g */
                return stat(opnd1, &b1) == 0 &&
                    (b1.st_mode & S_ISGID) == S_ISGID;
        case TO_FILSTCK: /* -k */
                return stat(opnd1, &b1) == 0 &&
                    (b1.st_mode & S_ISVTX) == S_ISVTX;
        case TO_FILGZ: /* -s */
                return stat(opnd1, &b1) == 0 && b1.st_size > 0L;
        case TO_FILTT: /* -t */
                if (!bi_getn(opnd1, &res)) {
                        te->flags |= TEF_ERROR;
                        return 0;
                }
                return isatty(res);
        case TO_FILUID: /* -O */
                return stat(opnd1, &b1) == 0 && b1.st_uid == ksheuid;
        case TO_FILGID: /* -G */
                return 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 */
                {
                        int64_t v1, v2;

                        if (!evaluate(opnd1, &v1, KSH_RETURN_ERROR, false) ||
                            !evaluate(opnd2, &v2, KSH_RETURN_ERROR, false)) {
                                /* 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 &&
                            timespeccmp(&b1.st_mtim, &b2.st_mtim, >)) ||
                            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 &&
                            timespeccmp(&b1.st_mtim, &b2.st_mtim, <)) ||
                            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;
}

/* Routine to deal with X_OK on non-directories when running as root.
 */
static int
test_eaccess(const char *path, int amode)
{
        int res;

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

                if (stat(path, &statb) == -1)
                        res = -1;
                else if (S_ISDIR(statb.st_mode))
                        res = 0;
                else
                        res = (statb.st_mode & (S_IXUSR|S_IXGRP|S_IXOTH)) ?
                            0 : -1;
        }

        return res;
}

int
test_parse(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(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(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(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(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;
        }
        /*
         * Binary should have precedence over unary in this case
         * so that something like test \( -f = -f \) is accepted
         */
        if ((te->flags & TEF_DBRACKET) || (&te->pos.wp[1] < te->wp_end &&
            !test_isop(te, TM_BINOP, te->pos.wp[1]))) {
                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, NULL,
                            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, NULL, 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(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(Test_env *te, Test_op op, int do_eval)
{
        if (te->pos.wp >= te->wp_end)
                return NULL;
        return *te->pos.wp++;
}

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

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