Write a program in C++ to display the following information from Linux. 1. Gener

Question

Write a program in C++ to display the following information from Linux.

1. General information.

In this section you will assemble some basic facts about the system

a.   Machine name (hostname) # get this information from /proc/sys/kernel/hostname
b.   System date and time     # get this information from /proc/driver/rtc
c.   Kernel version # get this information from /proc/version
d.   Memory usage (used and free memory) # get this information from /proc/meminfo

2. Time information.

In this section you will print out how long the system has been up and how busy it has been.

a. Duration of uptime # get these information from /proc/uptime
b. Duration of idletime

The skeleton of the program

(1) read file

Explanation / Answer

Here is the program for obtaining all the values from the 'Proc' Pseudo-Filesystem.

#include <iostream>
#include <stdio.h>
#include <cstring>

using namespace std;

int main()
{
   float uptime, idletime;
   FILE* fp;
   fp = fopen("/proc/uptime","r");
   fscanf(fp,"%f %f",&uptime, &idletime);
   printf("Uptime: %.2f ",uptime);
   printf("Idletime: %.2f ",idletime);

   /*
   printf("Seconds %d: ",uptime%60);
   uptime =   uptime /60;
   printf("Minutes %d: ",uptime%60);
   uptime =   uptime /60;
   printf("Hours %d: ",uptime%60);

   */

   fclose(fp);

   char hostname[100];
   fp = fopen("/proc/sys/kernel/hostname", "r");
   fscanf(fp, "%s", &hostname);
   printf("Hostname: %s ", hostname);
   fclose(fp);

   fp = fopen("/proc/version", "r");
   int i = 0;
   char a[1000][100];
   while(fscanf(fp,"%s",&a[++i]) != EOF)
   {
       //printf("%s", a[i-1]);
   }
   fclose(fp);
   int n=i;
   for(i=1;i<=n;i++)
   {
       if(!strcmp("Linux",a[i]) && !strcmp("version",a[i+1]) )
       {
           printf("Linux Version: %s ", a[i+2]);
           break;      
       }
   }

   fp = fopen("/proc/meminfo", "r");
   i = 0;
   char mem[1000][100];
   while(fscanf(fp,"%s",&mem[++i]) != EOF)
   {
  
   }
   fclose(fp);
   n=i;
   for(i=1;i<=n;i++)
   {
       if(!strcmp("MemFree:",mem[i]) )
       {
           printf("Memory Free: %s kB ", mem[i+1]);
           break;
       }
   }

   fp = fopen("/proc/driver/rtc", "r");
   i = 0;
   char rtc[1000][100];
   while(fscanf(fp,"%s",&rtc[++i]) != EOF)
   {
  
   }
   fclose(fp);
   n=i;
   for(i=1;i<=n;i++)
   {
       if(!strcmp("rtc_time",rtc[i]) )
       {
           printf("TIME: %s ", rtc[i+2]);
       }
       if(!strcmp("rtc_date",rtc[i]) )
       {
           printf("DATE: %s ", rtc[i+2]);
           break;
       }
   }

}

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