xsh_uptime.c

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/* xsh_uptime.c - xsh_uptime */

#include <xinu.h>
#include <stdio.h>
#include <string.h>

/*------------------------------------------------------------------------
 * xsh_uptime - shell to print the time the system has been up
 *------------------------------------------------------------------------
 */
shellcmd xsh_uptime(int nargs, char *args[])
{
    uint32  days, hrs, mins, secs;  /* days, hours, minutes,  and   */
                    /*  seconds since system boot   */
    uint32  secperday = 86400;  /* seconds in a day     */
    uint32  secperhr  =  3600;  /* seconds in an hour       */
    uint32  secpermin =    60;  /* seconds in a minute      */  

    /* For argument '--help', emit help about the 'uptime' command  */

    if (nargs == 2 && strncmp(args[1], "--help", 7) == 0) {
        printf("Use: %s\n\n", args[0]);
        printf("Description:\n");
        printf("\tDisplays time since the system booted\n");
        printf("Options:\n");
        printf("\t--help\t display this help and exit\n");
        return 0;
    }

    /* Check for valid number of arguments */

    if (nargs > 1) {
        fprintf(stderr, "%s: too many arguments\n", args[0]);
        fprintf(stderr, "Try '%s --help' for more information\n",
                args[0]);
        return 1;
    }

    secs = clktime;     /* total seconds since boot */

    /* subtract number of whole days */

    days  = secs/secperday;
    secs -= days*secperday;

    /* subtract number of hours */

    hrs   = secs/secperhr;
    secs -= hrs*secperhr;

    /* subtract number of minutes */

    mins  = secs/secpermin;
    secs -= mins*secpermin;

    printf("Xinu has been up ");
    if (days > 0) {
        printf(" %d day(s) ", days);
    }

    if (hrs > 0) {
        printf(" %d hour(s) ", hrs);
    }

    if (mins > 0) {
        printf(" %d minute(s) ", mins);
    }

    if (secs > 0) {
        printf(" %d second(s) ", secs);
    }
    printf("\n");

    return 0;
}