1 /**

     2  * sts.c: show time stamp

     3  * Copyright (C) 2010 Markus Broeker

     4  */

     5 

     6 #include <stdio.h>

     7 #include <stdlib.h>

     8 #include <string.h>

     9 #include <math.h>

    10 #include <time.h>

    11 #include <errno.h>

    12 

    13 void usage (char *name)

    14 {

    15     printf ("Usage: %s STAMP [BOOT-STAMP]\n", name);

    16     exit (EXIT_FAILURE);

    17 }

    18 

    19 time_t parse (char *buf)

    20 {

    21     time_t sec = 0;

    22     time_t milli = 0;

    23     double value;

    24 

    25     if (sscanf (buf, "%ld.%ld", &sec, &milli) != 2) {

    26         fprintf (stderr, "  sec: %ld, ", sec);

    27         fprintf (stderr, "milli: %ld\n", milli);

    28     }

    29 

    30     value = (milli / 1000000);

    31     return sec + (time_t) (floor (value));

    32 }

    33 

    34 time_t getboottime ()

    35 {

    36     char buf[80];

    37     time_t now = time (NULL);

    38 

    39     FILE *f = fopen ("/proc/uptime", "r");

    40     if (fgets (buf, sizeof (buf), f) == NULL) {

    41         perror ("FOPEN");

    42         exit (errno);

    43     }

    44 

    45     fclose (f);

    46     return now - parse (buf);

    47 }

    48 

    49 int main (int argc, char **argv)

    50 {

    51     time_t boot;

    52     time_t stamp = 0;

    53     time_t diff;

    54 

    55     if (argc < 2)

    56         usage (argv[0]);

    57 

    58     stamp = parse (argv[1]);

    59 

    60     if (argc == 3) {

    61         boot = parse (argv[2]);

    62     } else

    63         boot = getboottime ();

    64 

    65     diff = boot + stamp;

    66     printf ("%s: %s", argv[1], ctime (&diff));

    67 

    68     return EXIT_SUCCESS;

    69 }