/*
 * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*      Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
/*        All Rights Reserved   */

/*
 * Copyright (c) 1980 Regents of the University of California.
 * All rights reserved. The Berkeley software License Agreement
 * specifies the terms and conditions for redistribution.
 */

/*
 * test expression
 * [ expression ]
 */

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <string.h>

#define EQ(a, b)        ((strcmp(a, b) == 0))

static char *nxtarg(int mt);
static int exp(void);
static int e1(void);
static int e2(void);
static int e3(void);
static int tio(char *a, int f);
static int ftype(char *f, int field);
static int filtyp(char *f, int field);
static int fsizep(char *f);
static void synbad(char *s1, char *s2);

static int      ap;
static int      ac;
static char     **av;

int
main(int argc, char *argv[])
{
        int status;

        ac = argc; av = argv; ap = 1;
        if (EQ(argv[0], "[")) {
                if (!EQ(argv[--ac], "]"))
                        synbad("] missing", "");
        }
        argv[ac] = 0;
        if (ac <= 1)
                exit(1);
        status = (exp() ? 0 : 1);
        if (nxtarg(1) != 0)
                synbad("too many arguments", "");
        return (status);
}

static char *
nxtarg(int mt)
{
        if (ap >= ac) {
                if (mt) {
                        ap++;
                        return (0);
                }
                synbad("argument expected", "");
        }
        return (av[ap++]);
}

static int
exp(void)
{
        int p1;
        char *p2;

        p1 = e1();
        p2 = nxtarg(1);
        if (p2 != 0) {
                if (EQ(p2, "-o"))
                        return (p1 | exp());
                if (EQ(p2, "]"))
                        synbad("syntax error", "");
        }
        ap--;
        return (p1);
}

static int
e1(void)
{
        int p1;
        char *p2;

        p1 = e2();
        p2 = nxtarg(1);
        if ((p2 != 0) && EQ(p2, "-a"))
                return (p1 & e1());
        ap--;
        return (p1);
}

static int
e2(void)
{
        if (EQ(nxtarg(0), "!"))
                return (!e3());
        ap--;
        return (e3());
}

static int
e3(void)
{
        int p1;
        char *a;
        char *p2;
        int int1, int2;

        a = nxtarg(0);
        if (EQ(a, "(")) {
                p1 = exp();
                if (!EQ(nxtarg(0), ")")) synbad(") expected", "");
                return (p1);
        }
        p2 = nxtarg(1);
        ap--;
        if ((p2 == 0) || (!EQ(p2, "=") && !EQ(p2, "!="))) {
                if (EQ(a, "-r"))
                        return (tio(nxtarg(0), 4));

                if (EQ(a, "-w"))
                        return (tio(nxtarg(0), 2));

                if (EQ(a, "-x"))
                        return (tio(nxtarg(0), 1));

                if (EQ(a, "-d"))
                        return (filtyp(nxtarg(0), S_IFDIR));

                if (EQ(a, "-c"))
                        return (filtyp(nxtarg(0), S_IFCHR));

                if (EQ(a, "-b"))
                        return (filtyp(nxtarg(0), S_IFBLK));

                if (EQ(a, "-f")) {
                        struct stat statb;

                        return (stat(nxtarg(0), &statb) >= 0 &&
                            (statb.st_mode & S_IFMT) != S_IFDIR);
                }

                if (EQ(a, "-h"))
                        return (filtyp(nxtarg(0), S_IFLNK));

                if (EQ(a, "-u"))
                        return (ftype(nxtarg(0), S_ISUID));

                if (EQ(a, "-g"))
                        return (ftype(nxtarg(0), S_ISGID));

                if (EQ(a, "-k"))
                        return (ftype(nxtarg(0), S_ISVTX));

                if (EQ(a, "-p"))
#ifdef S_IFIFO
                        return (filtyp(nxtarg(0), S_IFIFO));
#else
                        return (nxtarg(0), 0);
#endif

                if (EQ(a, "-s"))
                        return (fsizep(nxtarg(0)));

                if (EQ(a, "-t"))
                        if (ap >= ac)
                                return (isatty(1));
                        else if (EQ((a = nxtarg(0)), "-a") || EQ(a, "-o")) {
                                ap--;
                                return (isatty(1));
                        } else
                                return (isatty(atoi(a)));

                if (EQ(a, "-n"))
                        return (!EQ(nxtarg(0), ""));
                if (EQ(a, "-z"))
                        return (EQ(nxtarg(0), ""));
        }

        p2 = nxtarg(1);
        if (p2 == 0)
                return (!EQ(a, ""));
        if (EQ(p2, "-a") || EQ(p2, "-o")) {
                ap--;
                return (!EQ(a, ""));
        }
        if (EQ(p2, "="))
                return (EQ(nxtarg(0), a));

        if (EQ(p2, "!="))
                return (!EQ(nxtarg(0), a));

        int1 = atoi(a);
        int2 = atoi(nxtarg(0));
        if (EQ(p2, "-eq"))
                return (int1 == int2);
        if (EQ(p2, "-ne"))
                return (int1 != int2);
        if (EQ(p2, "-gt"))
                return (int1 > int2);
        if (EQ(p2, "-lt"))
                return (int1 < int2);
        if (EQ(p2, "-ge"))
                return (int1 >= int2);
        if (EQ(p2, "-le"))
                return (int1 <= int2);

        synbad("unknown operator ", p2);
        /* NOTREACHED */
        return (0);
}

static int
tio(char *a, int f)
{
        if (access(a, f) == 0)
                return (1);
        else
                return (0);
}

static int
ftype(char *f, int field)
{
        struct stat statb;

        if (stat(f, &statb) < 0)
                return (0);
        if ((statb.st_mode & field) == field)
                return (1);
        return (0);
}

static int
filtyp(char *f, int field)
{
        struct stat statb;

        if (field == S_IFLNK) {
                if (lstat(f, &statb) < 0)
                        return (0);
        } else {
                if (stat(f, &statb) < 0)
                        return (0);
        }
        if ((statb.st_mode & S_IFMT) == field)
                return (1);
        else
                return (0);
}

static int
fsizep(char *f)
{
        struct stat statb;

        if (stat(f, &statb) < 0)
                return (0);
        return (statb.st_size > 0);
}

static void
synbad(char *s1, char *s2)
{
        (void) write(2, "test: ", 6);
        (void) write(2, s1, strlen(s1));
        (void) write(2, s2, strlen(s2));
        (void) write(2, "\n", 1);
        exit(255);
}