time.c

#include <math.h>
#include <utmp.h> 
#include <sys/ioctl.h>
#include <dirent.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/sysinfo.h>
#include <string.h>
#include <time.h>





static int get_time(int pos, char * headline) {

    struct sysinfo info;
    struct tm *realtime;
    time_t realseconds;

    sysinfo(&info);
    time(&realseconds);
    realtime = localtime(&realseconds);
    pos = sprintf(headline, " %02d:%02d:%02d up",
    realtime->tm_hour, realtime->tm_min, realtime->tm_sec);

    struct tm *runtime;
    runtime = gmtime( &info.uptime );
    pos += sprintf(headline + pos, "  %02d:%02d, ",realtime->tm_hour, realtime->tm_min);

    return(pos);
}

static void get_user(int pos, char* headline){

    FILE * ptrtime;
    char buffer[100];
    struct utmp *utmpstruct;

    int numuser = 0;
    setutent();
    while ((utmpstruct = getutent())) {
        if ((utmpstruct->ut_type == USER_PROCESS) &&
           (utmpstruct->ut_name[0] != '\0'))
            numuser++;
        }
    endutent();

    pos += sprintf(headline + pos, "%2d user%s, ", numuser, numuser == 1 ? "" : "s");

    double av[3];

    ptrtime = fopen("/proc/loadavg","r");
    fgets(buffer,100,ptrtime);
    sscanf(buffer,"%lf %lf %lf",&av[0], &av[1], &av[2]);
    fclose(ptrtime);

    pos += sprintf(headline + pos, " load average: %.2f, %.2f, %.2f",
                         av[0], av[1], av[2]);

}


char *sprint_uptime() {

    int pos = 0;
    char * headline1 = malloc(sizeof(char)*128);

    pos = get_time(pos, headline1);
    get_user(pos,headline1);

    return headline1;
}