Question

Need some help in parsing the file

Device#  Device Name                 Serial No.                  Active Policy         Disk#         P.B.T.L        ALB
                                                                     Paths                                        
---------------------------------------------------------------------------------------    -------------------------------------
 1       AB      OPEN-V-CM           50 0BC1F1621                          1    SQST           Disk  2       3.1.4.0         N/A
 2       AB      OPEN-V-CM           50 0BC1F1605                          1    SQST           Disk  3       3.1.4.1         N/A
 3       AB      OPEN-V*2            50 0BC1F11D4                          1    SQST           Disk  4       3.1.4.2         N/A
 4       AB      OPEN-V-CM           50 0BC1F005A                          1    SQST           Disk  5       3.1.4.3         N/A

The above information is in devices.txt file and and i want to extract the device number corresponding to the disk no i input.
The disk number i input is just an integer (and not “Disk 2” as shown in the file).

Answer 1

#include <sstream>
#include <fstream>
#include <iostream>
#include <cctype>
using namespace std;

int main(int argc, char* argv[])
{
    int wantedDisknum = 4;
    int finalDeviceNum = -1;

    ifstream fin("test.txt");

    if(!fin.is_open())
        return -1;

    while(!fin.eof())
    {
        string line;
        getline(fin, line);
        stringstream ss(line);

        int deviceNum;
        ss >> deviceNum;
        if(ss.fail())
        {
            ss.clear();
            continue;
        }

        string unused;
        int diskNum;
        ss >> unused >> unused >> unused >> unused >> unused >> unused >> unused >> diskNum;

        if(diskNum == wantedDisknum)
        {
            finalDeviceNum = deviceNum;
            break;
        }
    }

    fin.close();
    cout << finalDeviceNum << endl;

    system("pause");
    return 0;
}