/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright 2009 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) 1987, 1988 Microsoft Corporation  */
/*        All Rights Reserved   */

#include <sys/types.h>
#include <sys/stat.h>
#include <stdio.h>
#include <string.h>
#include <strings.h>
#include <stdlib.h>
#include <ctype.h>
#include <libgen.h>
#include <fcntl.h>
#include <pwd.h>
#include <time.h>
#include <unistd.h>
#include <locale.h>
#include <sys/time.h>
#include <errno.h>

#define BADTIME "bad time specification"

static char     *myname;

static int isnumber(char *);
static int atoi_for2(char *);
static void usage(const int);
static void touchabort(const char *);
static void parse_datetime(char *, timespec_t *);
static void parse_time(char *, timespec_t *);
static void parse_timespec(char *, timespec_t *);

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

        int             aflag   = 0;
        int             cflag   = 0;
        int             rflag   = 0;
        int             mflag   = 0;
        int             tflag   = 0;
        int             stflag  = 0;
        int             status  = 0;
        int             usecurrenttime = 1;
        int             timespecified;
        int             optc;
        int             fd = -1;
        mode_t          cmode =
            (S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH);
        struct stat     stbuf;
        struct stat     prstbuf;
        timespec_t      times[2];
        timespec_t      *tsp;

        (void) setlocale(LC_ALL, "");
#if !defined(TEXT_DOMAIN)
#define TEXT_DOMAIN "SYS_TEST"
#endif
        (void) textdomain(TEXT_DOMAIN);

        myname = basename(argv[0]);
        if (strcmp(myname, "settime") == 0) {
                cflag++;
                stflag++;
                while ((optc = getopt(argc, argv, "f:")) != EOF) {
                        switch (optc) {
                        case 'f':
                                rflag++;
                                usecurrenttime = 0;
                                if (stat(optarg, &prstbuf) == -1) {
                                        (void) fprintf(stderr, "%s: ", myname);
                                        perror(optarg);
                                        return (2);
                                }
                                break;
                        case '?':
                                usage(stflag);
                                break;
                        }
                }
        } else {
                while ((optc = getopt(argc, argv, "acfmr:d:t:")) != EOF) {
                        switch (optc) {
                        case 'a':
                                aflag++;
                                break;
                        case 'c':
                                cflag++;
                                break;
                        case 'f':       /* silently ignore for UCB compat */
                                break;
                        case 'm':
                                mflag++;
                                break;
                        case 'r':       /* same as settime's -f option */
                                rflag++;
                                usecurrenttime = 0;
                                if (stat(optarg, &prstbuf) == -1) {
                                        (void) fprintf(stderr, "%s: ", myname);
                                        perror(optarg);
                                        return (2);
                                }
                                break;
                        case 'd':
                                tflag++;
                                usecurrenttime = 0;
                                parse_datetime(optarg, &prstbuf.st_mtim);
                                prstbuf.st_atim = prstbuf.st_mtim;
                                break;
                        case 't':
                                tflag++;
                                usecurrenttime = 0;
                                parse_time(optarg, &prstbuf.st_mtim);
                                prstbuf.st_atim = prstbuf.st_mtim;
                                break;
                        case '?':
                                usage(stflag);
                                break;
                        }
                }
        }

        argc -= optind;
        argv += optind;

        if ((argc < 1) || (rflag + tflag > 1))
                usage(stflag);

        if ((aflag == 0) && (mflag == 0)) {
                aflag = 1;
                mflag = 1;
        }
        if ((aflag && !mflag) || (mflag && !aflag))
                usecurrenttime = 0;

        /*
         * If -r, -t or -d has been specified,
         * use the specified time.
         */
        timespecified = (rflag | tflag);

        if (timespecified == 0 && argc >= 2 && isnumber(*argv) &&
            (strlen(*argv) == 8 || strlen(*argv) == 10)) {
                /*
                 * time is specified as an operand; use it.
                 */
                parse_timespec(*argv++, &prstbuf.st_mtim);
                prstbuf.st_atim = prstbuf.st_mtim;
                usecurrenttime = 0;
                timespecified = 1;
                argc--;
        }

        for (c = 0; c < argc; c++) {
                if (stat(argv[c], &stbuf)) {
                        /*
                         * If stat failed for reasons other than EOVERFLOW or
                         * ENOENT, the file should not be created, since this
                         * can clobber the contents of an existing file.
                         */
                        if (errno == EOVERFLOW) {
                                /*
                                 * Since we have EOVERFLOW,
                                 * we know the file exists.
                                 */
                                /* EMPTY */;
                        } else if (errno != ENOENT) {
                                (void) fprintf(stderr,
                                    gettext("%s: cannot stat %s: %s\n"),
                                    myname, argv[c], strerror(errno));
                                status++;
                                continue;
                        } else if (cflag) {
                                continue;
                        } else if ((fd = creat(argv[c], cmode)) < 0) {
                                (void) fprintf(stderr,
                                    gettext("%s: cannot create %s: %s\n"),
                                    myname, argv[c], strerror(errno));
                                status++;
                                continue;
                        }
                }

                if (usecurrenttime) {
                        tsp = NULL;
                } else {
                        if (mflag == 0) {
                                /* Keep the mtime of the file */
                                times[1].tv_nsec = UTIME_OMIT;
                        } else if (timespecified) {
                                /* Set the specified time */
                                times[1] = prstbuf.st_mtim;
                        } else {
                                /* Otherwise, use the current time */
                                times[1].tv_nsec = UTIME_NOW;
                        }

                        if (aflag == 0) {
                                /* Keep the atime of the file */
                                times[0].tv_nsec = UTIME_OMIT;
                        } else if (timespecified) {
                                /* Set the specified time */
                                times[0] = prstbuf.st_atim;
                        } else {
                                /* Otherwise, use the current time */
                                times[0].tv_nsec = UTIME_NOW;
                        }

                        tsp = times;
                }

                if ((fd >= 0 && futimens(fd, tsp) != 0) ||
                    (fd < 0 && utimensat(AT_FDCWD, argv[c], tsp, 0) != 0)) {
                        (void) fprintf(stderr,
                            gettext("%s: cannot change times on %s: %s\n"),
                            myname, argv[c], strerror(errno));
                        status++;
                }
                if (fd >= 0) {
                        (void) close(fd);
                        fd = -1;
                }
        }
        return (status);
}

static int
isnumber(char *s)
{
        int c;

        while ((c = *s++) != '\0')
                if (!isdigit(c))
                        return (0);
        return (1);
}

static void
parse_datetime(char *t, timespec_t *ts)
{
        char            date[64];
        char            *year;
        char            *month;
        char            *day;
        char            *hour;
        char            *minute;
        char            *second;
        char            *fraction;
        int             utc = 0;
        char            *p;
        time_t          when;
        int             nanoseconds;
        struct tm       tm;

        /*
         * The date string has the format (defined by the touch(1) spec):
         *      YYYY-MM-DDThh:mm:SS[.frac][tz]
         *      YYYY-MM-DDThh:mm:SS[,frac][tz]
         * T is either the literal 'T' or is a space character.
         * tz is either empty (local time) or the literal 'Z' (UTC).
         * All other fields are strings of digits.
         */

        /*
         * Make a copy of the date string so it can be tokenized.
         */
        if (strlcpy(date, t, sizeof (date)) >= sizeof (date))
                touchabort(BADTIME);

        /* deal with the optional trailing 'Z' first */
        p = date + strlen(date) - 1;
        if (*p == 'Z') {
                utc = 1;
                *p = '\0';
        }

        /* break out the component tokens */
        p = date;
        year = strsep(&p, "-");
        month = strsep(&p, "-");
        day = strsep(&p, "T ");
        hour = strsep(&p, ":");
        minute = strsep(&p, ":");
        second = strsep(&p, ".,");
        fraction = p;

        /* verify the component tokens */
        if (year == NULL || strlen(year) < 4 || !isnumber(year) ||
            month == NULL || strlen(month) != 2 || !isnumber(month) ||
            day == NULL || strlen(day) != 2 || !isnumber(day) ||
            hour == NULL || strlen(hour) != 2 || !isnumber(hour) ||
            minute == NULL || strlen(minute) != 2 || !isnumber(minute) ||
            second == NULL || strlen(second) != 2 || !isnumber(second) ||
            (fraction != NULL && (*fraction == '\0' || !isnumber(fraction))))
                touchabort(BADTIME);

        (void) memset(&tm, 0, sizeof (struct tm));

        tm.tm_year = atoi(year) - 1900;
        tm.tm_mon = atoi(month) - 1;
        tm.tm_mday = atoi(day);
        tm.tm_hour = atoi(hour);
        tm.tm_min = atoi(minute);
        tm.tm_sec = atoi(second);
        if (utc) {
                (void) setenv("TZ", "GMT0", 1);
                tzset();
        }

        errno = 0;
        if ((when = mktime(&tm)) == -1 && errno != 0)
                touchabort(BADTIME);
        if (tm.tm_isdst)
                when -= (timezone - altzone);

        if (fraction == NULL) {
                nanoseconds = 0;
        } else {
                /* truncate beyond 9 digits (nanoseconds) */
                if (strlen(fraction) > 9)
                        fraction[9] = '\0';
                nanoseconds = atoi(fraction);

                switch (strlen(fraction)) {
                case 1:
                        nanoseconds *= 100000000;
                        break;
                case 2:
                        nanoseconds *= 10000000;
                        break;
                case 3:
                        nanoseconds *= 1000000;
                        break;
                case 4:
                        nanoseconds *= 100000;
                        break;
                case 5:
                        nanoseconds *= 10000;
                        break;
                case 6:
                        nanoseconds *= 1000;
                        break;
                case 7:
                        nanoseconds *= 100;
                        break;
                case 8:
                        nanoseconds *= 10;
                        break;
                case 9:
                        break;
                }
        }

        ts->tv_sec = when;
        ts->tv_nsec = nanoseconds;
}

static void
parse_time(char *t, timespec_t *ts)
{
        int             century = 0;
        int             seconds = 0;
        char            *p;
        time_t          when;
        struct tm       tm;

        /*
         * time in the following format (defined by the touch(1) spec):
         *      [[CC]YY]MMDDhhmm[.SS]
         */
        if ((p = strchr(t, '.')) != NULL) {
                if (strchr(p+1, '.') != NULL)
                        touchabort(BADTIME);
                seconds = atoi_for2(p+1);
                *p = '\0';
        }

        (void) memset(&tm, 0, sizeof (struct tm));
        when = time(0);
        tm.tm_year = localtime(&when)->tm_year;

        switch (strlen(t)) {
                case 12:        /* CCYYMMDDhhmm */
                        century = atoi_for2(t);
                        t += 2;
                        /* FALLTHROUGH */
                case 10:        /* YYMMDDhhmm */
                        tm.tm_year = atoi_for2(t);
                        t += 2;
                        if (century == 0) {
                                if (tm.tm_year < 69)
                                        tm.tm_year += 100;
                        } else
                                tm.tm_year += (century - 19) * 100;
                        /* FALLTHROUGH */
                case 8:         /* MMDDhhmm */
                        tm.tm_mon = atoi_for2(t) - 1;
                        t += 2;
                        tm.tm_mday = atoi_for2(t);
                        t += 2;
                        tm.tm_hour = atoi_for2(t);
                        t += 2;
                        tm.tm_min = atoi_for2(t);
                        tm.tm_sec = seconds;
                        break;
                default:
                        touchabort(BADTIME);
        }

        if ((when = mktime(&tm)) == -1)
                touchabort(BADTIME);
        if (tm.tm_isdst)
                when -= (timezone-altzone);

        ts->tv_sec = when;
        ts->tv_nsec = 0;
}

static void
parse_timespec(char *t, timespec_t *ts)
{
        time_t          when;
        struct tm       tm;

        /*
         * time in the following format (defined by the touch(1) spec):
         *      MMDDhhmm[yy]
         */

        (void) memset(&tm, 0, sizeof (struct tm));
        when = time(0);
        tm.tm_year = localtime(&when)->tm_year;

        switch (strlen(t)) {
                case 10:        /* MMDDhhmmyy */
                        tm.tm_year = atoi_for2(t+8);
                        if (tm.tm_year < 69)
                                tm.tm_year += 100;
                        /* FALLTHROUGH */
                case 8:         /* MMDDhhmm */
                        tm.tm_mon = atoi_for2(t) - 1;
                        t += 2;
                        tm.tm_mday = atoi_for2(t);
                        t += 2;
                        tm.tm_hour = atoi_for2(t);
                        t += 2;
                        tm.tm_min = atoi_for2(t);
                        break;
                default:
                        touchabort(BADTIME);
        }

        if ((when = mktime(&tm)) == -1)
                touchabort(BADTIME);
        if (tm.tm_isdst)
                when -= (timezone - altzone);

        ts->tv_sec = when;
        ts->tv_nsec = 0;
}

static int
atoi_for2(char *p)
{
        int value;

        value = (*p - '0') * 10 + *(p+1) - '0';
        if ((value < 0) || (value > 99))
                touchabort(BADTIME);
        return (value);
}

static void
touchabort(const char *message)
{
        (void) fprintf(stderr, "%s: %s\n", myname, gettext(message));
        exit(1);
}

static void
usage(const int settime)
{
        if (settime) {
                (void) fprintf(stderr, gettext(
                    "usage: %s [-f file] [mmddhhmm[yy]] file...\n"), myname);
                exit(2);
        }
        (void) fprintf(stderr, gettext(
            "usage: %s [-acm] [-r ref_file] file...\n"
            "       %s [-acm] [-t [[CC]YY]MMDDhhmm[.SS]] file...\n"
            "       %s [-acm] [-d YYYY-MM-DDThh:mm:SS[.frac][Z]] file...\n"
            "       %s [-acm] [-d YYYY-MM-DDThh:mm:SS[,frac][Z]] file...\n"
            "       %s [-acm] [MMDDhhmm[yy]] file...\n"),
            myname, myname, myname, myname, myname);
        exit(2);
}