/* vi: set sw=4 ts=4: */
/*
 * Mini touch implementation for busybox
 *
 * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
 *
 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
 */

/* BB_AUDIT SUSv3 _NOT_ compliant -- options -a, -m, -r, -t not supported. */
/* http://www.opengroup.org/onlinepubs/007904975/utilities/touch.html */

/* Mar 16, 2003      Manuel Novoa III   (mjn3@codepoet.org)
 *
 * Previous version called open() and then utime().  While this will be
 * be necessary to implement -r and -t, it currently only makes things bigger.
 * Also, exiting on a failure was a bug.  All args should be processed.
 */

#include "libbb.h"

//config:config TOUCH
//config:       bool "touch"
//config:       default y
//config:       help
//config:         touch is used to create or change the access and/or
//config:         modification timestamp of specified files.

//applet:IF_TOUCH(APPLET_NOFORK(touch, touch, BB_DIR_BIN, BB_SUID_DROP, touch))

//kbuild:lib-$(CONFIG_TOUCH) += touch.o

//usage:#define touch_trivial_usage
//usage:       "[-c]" IF_DESKTOP(" [-d DATE] [-r FILE]") " FILE [FILE]..."
//usage:#define touch_full_usage "\n\n"
//usage:       "Update the last-modified date on the given FILE[s]\n"
//usage:     "\n        -c      Don't create files"
//usage:        IF_DESKTOP(
//usage:     "\n        -d DT   Date/time to use"
//usage:     "\n        -r FILE Use FILE's date/time"
//usage:        )
//usage:
//usage:#define touch_example_usage
//usage:       "$ ls -l /tmp/foo\n"
//usage:       "/bin/ls: /tmp/foo: No such file or directory\n"
//usage:       "$ touch /tmp/foo\n"
//usage:       "$ ls -l /tmp/foo\n"
//usage:       "-rw-rw-r--    1 andersen andersen        0 Apr 15 01:11 /tmp/foo\n"

/* This is a NOFORK applet. Be very careful! */

/* coreutils implements:
 * -a   change only the access time
 * -c, --no-create
 *      do not create any files
 * -d, --date=STRING
 *      parse STRING and use it instead of current time
 * -f   (ignored, BSD compat)
 * -m   change only the modification time
 * -r, --reference=FILE
 *      use this file's times instead of current time
 * -t STAMP
 *      use [[CC]YY]MMDDhhmm[.ss] instead of current time
 * --time=WORD
 *      change the specified time: WORD is access, atime, or use
 */

int touch_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int touch_main(int argc UNUSED_PARAM, char **argv)
{
        int fd;
        int status = EXIT_SUCCESS;
        int opts;
#if ENABLE_DESKTOP
# if ENABLE_LONG_OPTS
        static const char touch_longopts[] ALIGN1 =
                /* name, has_arg, val */
                "no-create\0"         No_argument       "c"
                "reference\0"         Required_argument "r"
                "date\0"              Required_argument "d"
        ;
# endif
        char *reference_file = NULL;
        char *date_str = NULL;
        struct timeval timebuf[2];
        timebuf[1].tv_usec = timebuf[0].tv_usec = 0;
#else
# define reference_file NULL
# define date_str       NULL
# define timebuf        ((struct timeval*)NULL)
#endif

#if ENABLE_DESKTOP && ENABLE_LONG_OPTS
        applet_long_options = touch_longopts;
#endif
        /* -d and -t both set time. In coreutils,
         * accepted data format differs a bit between -d and -t.
         * We accept the same formats for both */
        opts = getopt32(argv, "c" IF_DESKTOP("r:d:t:")
                                /*ignored:*/ "fma"
                                IF_DESKTOP(, &reference_file)
                                IF_DESKTOP(, &date_str)
                                IF_DESKTOP(, &date_str)
        );

        opts &= 1; /* only -c bit is left */
        argv += optind;
        if (!*argv) {
                bb_show_usage();
        }

        if (reference_file) {
                struct stat stbuf;
                xstat(reference_file, &stbuf);
                timebuf[1].tv_sec = timebuf[0].tv_sec = stbuf.st_mtime;
        }

        if (date_str) {
                struct tm tm_time;
                time_t t;

                //memset(&tm_time, 0, sizeof(tm_time));
                /* Better than memset: makes "HH:MM" dates meaningful */
                time(&t);
                localtime_r(&t, &tm_time);
                parse_datestr(date_str, &tm_time);

                /* Correct any day of week and day of year etc. fields */
                tm_time.tm_isdst = -1;  /* Be sure to recheck dst */
                t = validate_tm_time(date_str, &tm_time);

                timebuf[1].tv_sec = timebuf[0].tv_sec = t;
        }

        do {
                if (utimes(*argv, (reference_file || date_str) ? timebuf : NULL) != 0) {
                        if (errno == ENOENT) { /* no such file */
                                if (opts) { /* creation is disabled, so ignore */
                                        continue;
                                }
                                /* Try to create the file */
                                fd = open(*argv, O_RDWR | O_CREAT, 0666);
                                if (fd >= 0) {
                                        xclose(fd);
                                        if (reference_file || date_str)
                                                utimes(*argv, timebuf);
                                        continue;
                                }
                        }
                        status = EXIT_FAILURE;
                        bb_simple_perror_msg(*argv);
                }
        } while (*++argv);

        return status;
}