/*      $OpenBSD: test.c,v 1.23 2025/03/24 20:15:08 millert Exp $       */
/*      $NetBSD: test.c,v 1.15 1995/03/21 07:04:06 cgd 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 J.T. Conklin for NetBSD.
 *
 * This program is in the Public Domain.
 */

#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <ctype.h>
#include <errno.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <err.h>

/* 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>
*/

enum token {
        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
};

enum token_types {
        UNOP,
        BINOP,
        BUNOP,
        BBINOP,
        PAREN
};

struct t_op {
        const char *op_text;
        short op_num, op_type;
} const ops [] = {
        {"-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},
        {"-O",  FILUID, UNOP},
        {"-G",  FILGID, UNOP},
        {"-L",  FILSYM, UNOP},
        {"-S",  FILSOCK,UNOP},
        {"=",   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},
        {0,     0,      0}
};

char **t_wp;
struct t_op const *t_wp_op;

static enum token t_lex(char *);
static enum token_types t_lex_type(char *);
static int oexpr(enum token n);
static int aexpr(enum token n);
static int nexpr(enum token n);
static int binop(void);
static int primary(enum token n);
static const char *getnstr(const char *, int *, size_t *);
static int intcmp(const char *, const char *);
static int filstat(char *nm, enum token mode);
static int getn(const char *s);
static int newerf(const char *, const char *);
static int olderf(const char *, const char *);
static int equalf(const char *, const char *);
static __dead void syntax(const char *op, char *msg);

int
main(int argc, char *argv[])
{
        extern char *__progname;
        int     res;

        if (pledge("stdio rpath", NULL) == -1)
                err(2, "pledge");

        if (strcmp(__progname, "[") == 0) {
                if (strcmp(argv[--argc], "]"))
                        errx(2, "missing ]");
                argv[argc] = NULL;
        }

        /* Implement special cases from POSIX.2, section 4.62.4 */
        switch (argc) {
        case 1:
                return 1;
        case 2:
                return (*argv[1] == '\0');
        case 3:
                if (argv[1][0] == '!' && argv[1][1] == '\0') {
                        return !(*argv[2] == '\0');
                }
                break;
        case 4:
                if (argv[1][0] != '!' || argv[1][1] != '\0') {
                        if (t_lex(argv[2]),
                            t_wp_op && t_wp_op->op_type == BINOP) {
                                t_wp = &argv[1];
                                return (binop() == 0);
                        }
                }
                break;
        case 5:
                if (argv[1][0] == '!' && argv[1][1] == '\0') {
                        if (t_lex(argv[3]),
                            t_wp_op && t_wp_op->op_type == BINOP) {
                                t_wp = &argv[2];
                                return !(binop() == 0);
                        }
                }
                break;
        }

        t_wp = &argv[1];
        res = !oexpr(t_lex(*t_wp));

        if (*t_wp != NULL && *++t_wp != NULL)
                syntax(*t_wp, "unknown operand");

        return res;
}

static __dead void
syntax(const char *op, char *msg)
{
        if (op && *op)
                errx(2, "%s: %s", op, msg);
        else
                errx(2, "%s", msg);
}

static int
oexpr(enum token n)
{
        int res;

        res = aexpr(n);
        if (t_lex(*++t_wp) == BOR)
                return oexpr(t_lex(*++t_wp)) || res;
        t_wp--;
        return res;
}

static int
aexpr(enum token n)
{
        int res;

        res = nexpr(n);
        if (t_lex(*++t_wp) == BAND)
                return aexpr(t_lex(*++t_wp)) && res;
        t_wp--;
        return res;
}

static int
nexpr(enum token n)
{
        if (n == UNOT)
                return !nexpr(t_lex(*++t_wp));
        return primary(n);
}

static int
primary(enum token n)
{
        int res;

        if (n == EOI)
                syntax(NULL, "argument expected");
        if (n == LPAREN) {
                res = oexpr(t_lex(*++t_wp));
                if (t_lex(*++t_wp) != RPAREN)
                        syntax(NULL, "closing paren expected");
                return res;
        }
        /*
         * We need this, if not binary operations with more than 4
         * arguments will always fall into unary.
         */
        if(t_lex_type(t_wp[1]) == BINOP) {
                t_lex(t_wp[1]);
                if (t_wp_op && t_wp_op->op_type == BINOP)
                        return binop();
        }

        if (t_wp_op && t_wp_op->op_type == UNOP) {
                /* unary expression */
                if (*++t_wp == NULL)
                        syntax(t_wp_op->op_text, "argument expected");
                switch (n) {
                case STREZ:
                        return strlen(*t_wp) == 0;
                case STRNZ:
                        return strlen(*t_wp) != 0;
                case FILTT:
                        return isatty(getn(*t_wp));
                default:
                        return filstat(*t_wp, n);
                }
        }

        return strlen(*t_wp) > 0;
}

static const char *
getnstr(const char *s, int *signum, size_t *len)
{
        const char *p, *start;

        /* skip leading whitespaces */
        p = s;
        while (isspace((unsigned char)*p))
                p++;

        /* accept optional sign */
        if (*p == '-') {
                *signum = -1;
                p++;
        } else {
                *signum = 1;
                if (*p == '+')
                        p++;
        }

        /* skip leading zeros */
        while (*p == '0' && isdigit((unsigned char)p[1]))
                p++;

        /* turn 0 always positive */
        if (*p == '0')
                *signum = 1;

        start = p;
        while (isdigit((unsigned char)*p))
                p++;
        *len = p - start;

        /* allow trailing whitespaces */
        while (isspace((unsigned char)*p))
                p++;

        /* validate number */
        if (*p != '\0' || *start == '\0')
                errx(2, "%s: invalid", s);

        return start;
}

static int
intcmp(const char *opnd1, const char *opnd2)
{
        const char *p1, *p2;
        size_t len1, len2;
        int c, sig1, sig2;

        p1 = getnstr(opnd1, &sig1, &len1);
        p2 = getnstr(opnd2, &sig2, &len2);

        if (sig1 != sig2)
                c = sig1;
        else if (len1 != len2)
                c = (len1 < len2) ? -sig1 : sig1;
        else
                c = strncmp(p1, p2, len1) * sig1;

        return c;
}

static int
binop(void)
{
        const char *opnd1, *opnd2;
        struct t_op const *op;

        opnd1 = *t_wp;
        (void) t_lex(*++t_wp);
        op = t_wp_op;

        if ((opnd2 = *++t_wp) == NULL)
                syntax(op->op_text, "argument expected");

        switch (op->op_num) {
        case STREQ:
                return strcmp(opnd1, opnd2) == 0;
        case STRNE:
                return strcmp(opnd1, opnd2) != 0;
        case STRLT:
                return strcmp(opnd1, opnd2) < 0;
        case STRGT:
                return strcmp(opnd1, opnd2) > 0;
        case INTEQ:
                return intcmp(opnd1, opnd2) == 0;
        case INTNE:
                return intcmp(opnd1, opnd2) != 0;
        case INTGE:
                return intcmp(opnd1, opnd2) >= 0;
        case INTGT:
                return intcmp(opnd1, opnd2) > 0;
        case INTLE:
                return intcmp(opnd1, opnd2) <= 0;
        case INTLT:
                return intcmp(opnd1, opnd2) < 0;
        case FILNT:
                return newerf(opnd1, opnd2);
        case FILOT:
                return olderf(opnd1, opnd2);
        case FILEQ:
                return equalf(opnd1, opnd2);
        }

        syntax(op->op_text, "not a binary operator");
}

static enum token_types
t_lex_type(char *s)
{
        struct t_op const *op = ops;

        if (s == NULL)
                return -1;

        while (op->op_text) {
                if (strcmp(s, op->op_text) == 0)
                        return op->op_type;
                op++;
        }
        return -1;
}

static int
filstat(char *nm, enum token mode)
{
        struct stat s;
        mode_t i;

        switch (mode) {
        case FILRD:
                return access(nm, R_OK) == 0;
        case FILWR:
                return access(nm, W_OK) == 0;
        case FILEX:
                return access(nm, X_OK) == 0;
        case FILEXIST:
                return access(nm, F_OK) == 0;
        default:
                break;
        }

        if (mode == FILSYM) {
                if (lstat(nm, &s) == 0) {
                        i = S_IFLNK;
                        goto filetype;
                }
                return 0;
        }

        if (stat(nm, &s) != 0)
                return 0;

        switch (mode) {
        case FILREG:
                i = S_IFREG;
                goto filetype;
        case FILDIR:
                i = S_IFDIR;
                goto filetype;
        case FILCDEV:
                i = S_IFCHR;
                goto filetype;
        case FILBDEV:
                i = S_IFBLK;
                goto filetype;
        case FILFIFO:
                i = S_IFIFO;
                goto filetype;
        case FILSOCK:
                i = S_IFSOCK;
                goto filetype;
        case FILSUID:
                i = S_ISUID;
                goto filebit;
        case FILSGID:
                i = S_ISGID;
                goto filebit;
        case FILSTCK:
                i = S_ISVTX;
                goto filebit;
        case FILGZ:
                return s.st_size > 0L;
        case FILUID:
                return s.st_uid == geteuid();
        case FILGID:
                return s.st_gid == getegid();
        default:
                return 1;
        }

filetype:
        return ((s.st_mode & S_IFMT) == i);

filebit:
        return ((s.st_mode & i) != 0);
}

static enum token
t_lex(char *s)
{
        struct t_op const *op = ops;

        if (s == 0) {
                t_wp_op = NULL;
                return EOI;
        }
        while (op->op_text) {
                if (strcmp(s, op->op_text) == 0) {
                        t_wp_op = op;
                        return op->op_num;
                }
                op++;
        }
        t_wp_op = NULL;
        return OPERAND;
}

/* atoi with error detection */
static int
getn(const char *s)
{
        char buf[32];
        const char *errstr, *p;
        size_t len;
        int r, sig;

        p = getnstr(s, &sig, &len);
        if (sig != 1)
                errstr = "too small";
        else if (len >= sizeof(buf))
                errstr = "too large";
        else {
                strlcpy(buf, p, sizeof(buf));
                buf[len] = '\0';
                r = strtonum(buf, 0, INT_MAX, &errstr);
        }

        if (errstr != NULL)
                errx(2, "%s: %s", s, errstr);

        return r;
}

static int
newerf(const char *f1, const char *f2)
{
        struct stat b1, b2;

        return (stat(f1, &b1) == 0 &&
            stat(f2, &b2) == 0 &&
            timespeccmp(&b1.st_mtim, &b2.st_mtim, >));
}

static int
olderf(const char *f1, const char *f2)
{
        struct stat b1, b2;

        return (stat(f1, &b1) == 0 &&
            stat(f2, &b2) == 0 &&
            timespeccmp(&b1.st_mtim, &b2.st_mtim, <));
}

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);
}