/*      $OpenBSD: touch.c,v 1.27 2022/01/29 00:06:26 cheloha Exp $      */
/*      $NetBSD: touch.c,v 1.11 1995/08/31 22:10:06 jtc Exp $   */

/*
 * Copyright (c) 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/types.h>
#include <sys/stat.h>
#include <sys/time.h>

#include <ctype.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>

void            stime_arg1(char *, struct timespec *);
void            stime_arg2(char *, int, struct timespec *);
void            stime_argd(char *, struct timespec *);
void            stime_file(char *, struct timespec *);
static void __dead usage(void);

int
main(int argc, char *argv[])
{
        struct timespec  ts[2];
        int              aflag, cflag, mflag, ch, fd, len, rval, timeset;
        char            *p;

        if (pledge("stdio rpath wpath cpath fattr", NULL) == -1)
                err(1, "pledge");

        aflag = cflag = mflag = timeset = 0;
        while ((ch = getopt(argc, argv, "acd:fmr:t:")) != -1)
                switch (ch) {
                case 'a':
                        aflag = 1;
                        break;
                case 'c':
                        cflag = 1;
                        break;
                case 'd':
                        timeset = 1;
                        stime_argd(optarg, ts);
                        break;
                case 'f':
                        break;
                case 'm':
                        mflag = 1;
                        break;
                case 'r':
                        timeset = 1;
                        stime_file(optarg, ts);
                        break;
                case 't':
                        timeset = 1;
                        stime_arg1(optarg, ts);
                        break;
                default:
                        usage();
                }
        argc -= optind;
        argv += optind;

        /* Default is both -a and -m. */
        if (aflag == 0 && mflag == 0)
                aflag = mflag = 1;

        /*
         * If no -r or -t flag, at least two operands, the first of which
         * is an 8 or 10 digit number, use the obsolete time specification.
         */
        if (!timeset && argc > 1) {
                (void)strtol(argv[0], &p, 10);
                len = p - argv[0];
                if (*p == '\0' && (len == 8 || len == 10)) {
                        timeset = 1;
                        stime_arg2(*argv++, len == 10, ts);
                }
        }

        /* Otherwise use the current time of day. */
        if (!timeset)
                ts[0].tv_nsec = ts[1].tv_nsec = UTIME_NOW;

        if (!aflag)
                ts[0].tv_nsec = UTIME_OMIT;
        if (!mflag)
                ts[1].tv_nsec = UTIME_OMIT;

        if (*argv == NULL)
                usage();

        for (rval = 0; *argv; ++argv) {
                /* Update the file's timestamp if it exists. */
                if (! utimensat(AT_FDCWD, *argv, ts, 0))
                        continue;
                if (errno != ENOENT) {
                        rval = 1;
                        warn("%s", *argv);
                        continue;
                }

                /* Didn't exist; should we create it? */
                if (cflag)
                        continue;

                /* Create the file. */
                fd = open(*argv, O_WRONLY | O_CREAT, DEFFILEMODE);
                if (fd == -1) {
                        rval = 1;
                        warn("%s", *argv);
                        continue;
                }
                if (futimens(fd, ts) == -1) {
                        warn("%s", *argv);
                        rval = 1;
                }
                if (close(fd) == -1) {
                        warn("%s", *argv);
                        rval = 1;
                }
        }
        return rval;
}

#define ATOI2(s)        ((s) += 2, ((s)[-2] - '0') * 10 + ((s)[-1] - '0'))

void
stime_arg1(char *arg, struct timespec *tsp)
{
        struct tm       *lt;
        time_t           tmptime;
        int              yearset;
        char            *dot, *p;
                                        /* Start with the current time. */
        tmptime = time(NULL);
        if ((lt = localtime(&tmptime)) == NULL)
                err(1, "localtime");
                                        /* [[CC]YY]MMDDhhmm[.SS] */
        for (p = arg, dot = NULL; *p != '\0'; p++) {
                if (*p == '.' && dot == NULL)
                        dot = p;
                else if (!isdigit((unsigned char)*p))
                        goto terr;
        }
        if (dot == NULL)
                lt->tm_sec = 0;         /* Seconds defaults to 0. */
        else {
                *dot++ = '\0';
                if (strlen(dot) != 2)
                        goto terr;
                lt->tm_sec = ATOI2(dot);
                if (lt->tm_sec > 61)    /* Could be leap second. */
                        goto terr;
        }

        yearset = 0;
        switch (strlen(arg)) {
        case 12:                        /* CCYYMMDDhhmm */
                lt->tm_year = (ATOI2(arg) * 100) - 1900;
                yearset = 1;
                /* FALLTHROUGH */
        case 10:                        /* YYMMDDhhmm */
                if (yearset) {
                        yearset = ATOI2(arg);
                        lt->tm_year += yearset;
                } else {
                        yearset = ATOI2(arg);
                        /* POSIX logic: [00,68]=>20xx, [69,99]=>19xx */
                        lt->tm_year = yearset;
                        if (yearset < 69)
                                lt->tm_year += 100;
                }
                /* FALLTHROUGH */
        case 8:                         /* MMDDhhmm */
                lt->tm_mon = ATOI2(arg);
                if (lt->tm_mon > 12 || lt->tm_mon == 0)
                        goto terr;
                --lt->tm_mon;           /* Convert from 01-12 to 00-11 */
                lt->tm_mday = ATOI2(arg);
                if (lt->tm_mday > 31 || lt->tm_mday == 0)
                        goto terr;
                lt->tm_hour = ATOI2(arg);
                if (lt->tm_hour > 23)
                        goto terr;
                lt->tm_min = ATOI2(arg);
                if (lt->tm_min > 59)
                        goto terr;
                break;
        default:
                goto terr;
        }

        lt->tm_isdst = -1;              /* Figure out DST. */
        tsp[0].tv_sec = tsp[1].tv_sec = mktime(lt);
        if (tsp[0].tv_sec == -1)
terr:           errx(1,
        "out of range or illegal time specification: [[CC]YY]MMDDhhmm[.SS]");

        tsp[0].tv_nsec = tsp[1].tv_nsec = 0;
}

void
stime_arg2(char *arg, int year, struct timespec *tsp)
{
        struct tm       *lt;
        time_t           tmptime;
                                        /* Start with the current time. */
        tmptime = time(NULL);
        if ((lt = localtime(&tmptime)) == NULL)
                err(1, "localtime");

        lt->tm_mon = ATOI2(arg);        /* MMDDhhmm[YY] */
        if (lt->tm_mon > 12 || lt->tm_mon == 0)
                goto terr;
        --lt->tm_mon;                   /* Convert from 01-12 to 00-11 */
        lt->tm_mday = ATOI2(arg);
        if (lt->tm_mday > 31 || lt->tm_mday == 0)
                goto terr;
        lt->tm_hour = ATOI2(arg);
        if (lt->tm_hour > 23)
                goto terr;
        lt->tm_min = ATOI2(arg);
        if (lt->tm_min > 59)
                goto terr;
        if (year) {
                year = ATOI2(arg);
                /* POSIX logic: [00,68]=>20xx, [69,99]=>19xx */
                lt->tm_year = year;
                if (year < 69)
                        lt->tm_year += 100;
        }
        lt->tm_sec = 0;

        lt->tm_isdst = -1;              /* Figure out DST. */
        tsp[0].tv_sec = tsp[1].tv_sec = mktime(lt);
        if (tsp[0].tv_sec == -1)
terr:           errx(1,
        "out of range or illegal time specification: MMDDhhmm[YY]");

        tsp[0].tv_nsec = tsp[1].tv_nsec = 0;
}

void
stime_file(char *fname, struct timespec *tsp)
{
        struct stat     sb;

        if (stat(fname, &sb))
                err(1, "%s", fname);
        tsp[0] = sb.st_atim;
        tsp[1] = sb.st_mtim;
}

void
stime_argd(char *arg, struct timespec *tsp)
{
        struct tm       tm;
        char            *frac, *p;
        int             utc = 0;

        /* accept YYYY-MM-DD(T| )hh:mm:ss[(.|,)frac][Z] */
        memset(&tm, 0, sizeof(tm));
        p = strptime(arg, "%F", &tm);
        if (p == NULL || (*p != 'T' && *p != ' '))
                goto terr;
        p = strptime(p + 1, "%T", &tm);
        if (p == NULL)
                goto terr;
        tsp[0].tv_nsec = 0;
        if (*p == '.' || *p == ',') {
                frac = ++p;
                while (isdigit((unsigned char)*p)) {
                        if (p - frac < 9) {
                                tsp[0].tv_nsec = tsp[0].tv_nsec * 10 +
                                    *p - '0';
                        }
                        p++;
                }
                if (p == frac)
                        goto terr;

                /* fill in the trailing zeros */
                while (p - frac-- < 9)
                        tsp[0].tv_nsec *= 10;
        }
        if (*p == 'Z') {
                utc = 1;
                p++;
        }
        if (*p != '\0')
                goto terr;

        tm.tm_isdst = -1;
        tsp[0].tv_sec = utc ? timegm(&tm) : mktime(&tm);
        if (tsp[0].tv_sec == -1)
terr:           errx(1,
  "out of range or illegal time specification: YYYY-MM-DDThh:mm:ss[.frac][Z]");
        tsp[1] = tsp[0];
}

static void __dead
usage(void)
{
        (void)fprintf(stderr,
"usage: touch [-acm] [-d ccyy-mm-ddTHH:MM:SS[.frac][Z]] [-r file]\n"
"             [-t [[cc]yy]mmddHHMM[.SS]] file ...\n");
        exit(1);
}