/*******************************************************************************
*
* timeset.c
*       
* AUTHOR:
*   Dan Harkless                                                    <opensource@
*   http://harkless.org/dan/software/                              harkless.org>
* 
* COPYRIGHT:
*   This file is Copyright (C) 2002 by Dan Harkless, and is released under the
*   GNU General Public License <http://www.gnu.org/copyleft/gpl.html>.
*
* USAGE:  
*   % timeset <dec_hex_or_oct_integer> <file_1> [<file_2>...]
*
* DESCRIPTION:                                                               
*   Sets the modification time of one or more files to the given integer value
*   (interpreted as seconds since the epoch).  That value can be given in
*   decimal, hexadecimal, or octal form.  The access time of the file(s) will be
*   preserved.  If one of them doesn't exist or has a permissions problem, an
*   error will be issued and the program will ultimately exit with nonzero
*   status, but the remaining files will still be processed in the meantime.
*                                                                            
* DATE        MODIFICATION
* ==========  ==================================================================
* 2002-03-16  Upgraded to work with more than one file.  Unfortunately, before,
*             I had the argument order as <file> <int> because I liked the way
*             "timeset <file> to <int>" read, but it's awkward to have 1...N
*             parameters not at the end of the commandline, so I changed the
*             timestamp to be the first argument, with the file(s) following.
*             Luckily it would be unlikely for someone to get burned by the
*             change, since the timestamp is enforced to be a legal integer
*             value (albeit in one of three bases) with no spurious characters.
* 2000-02-11  Original.
*
*******************************************************************************/
 

#include <sys/types.h>  /* supposed to precede <sys/stat.h> and <utime.h> */

#include <errno.h>      /* for errno */
#include <stdio.h>      /* for fprintf(), etc. */
#include <stdlib.h>     /* for strtol(), etc. */
#include <string.h>     /* for strerror() and strrchr() */
#include <sys/stat.h>   /* for stat() and struct stat */
#include <utime.h>      /* for struct utimbuf and utime() */


int  main(int  argc, char**  argv) {
    char*     char_after_number_ptr;
    char*     last_slash = strrchr(argv[0], '/');
    char*     our_program_name;
    int       exit_status = EXIT_SUCCESS, i;
    time_t    timestamp_integer;

    if (last_slash == NULL)
	our_program_name = argv[0];
    else
	our_program_name = last_slash + 1;
    
    if (argc < 3) {
        fprintf(stderr,
		"Usage: %s <dec_hex_or_oct_integer> <file_1> [<file_2>...]\n",
		our_program_name);
        return EXIT_FAILURE;
    }

    timestamp_integer = strtol(argv[1], &char_after_number_ptr, 0);
    
    if (errno != 0) {
	fprintf(stderr, "%s: \"%s\": %s.\n",
		our_program_name, argv[1], strerror(errno));
	return EXIT_FAILURE;
    }
    else if (*char_after_number_ptr != '\0') {
	fprintf(stderr, "%s: \"%s\": Illegal character in integer value.\n",
		our_program_name, argv[1]);
	fprintf(stderr, "%*c   %*c^\n",
		(int)strlen(our_program_name), ' ',
		char_after_number_ptr - argv[1], ' ');
	return EXIT_FAILURE;
    }

    for (i = 2; i < argc; i++) {
	struct stat  file_stat;

	if (stat(argv[i], &file_stat) < 0) {
	    fprintf(stderr, "%s: \"%s\": %s.\n",
		    our_program_name, argv[i], strerror(errno));
	    exit_status = EXIT_FAILURE;
	}
	else {
	    struct utimbuf  timestamp_struct;
	    
	    timestamp_struct.actime = file_stat.st_atime;
	    timestamp_struct.modtime = timestamp_integer;
	    
	    if (utime(argv[i], &timestamp_struct) < 0) {
		fprintf(stderr, "%s: \"%s\": %s.\n",
			our_program_name, argv[i], strerror(errno));
		exit_status = EXIT_FAILURE;
	    }
	}
    }

    return exit_status;
}