string & eof handling problems

My problem here is trying to test a substr of a string. when compiling I get the following errors

c:\work\programming\nettest\nt.h(40) : error C2146: syntax error : missing ';' before identifier 'path'
c:\work\programming\nettest\nt.h(40) : error C2501: 'string' : missing storage-class or type specifiers
c:\work\programming\nettest\nt.h(40) : error C2501: 'path' : missing storage-class or type specifiers
c:\work\programming\nettest\nt.cpp(47) : error C2679: binary '=' : no operator defined which takes a right-hand operand of type 'class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> >' (or there is no acceptable conv
ersion)
c:\work\programming\nettest\nt.cpp(61) : error C2039: 'path' : is not a member of 'netData'
c:\work\programming\nettest\nt.h(34) : see declaration of 'netData'
c:\work\programming\nettest\nt.cpp(84) : error C2440: 'return' : cannot convert from 'struct netData *' to 'struct netData'
No constructor could take the source type, or constructor overload resolution was ambiguous
c:\work\programming\nettest\nt.cpp(91) : error C2679: binary '=' : no operator defined which takes a right-hand operand of type 'struct netData' (or there is no acceptable conversion)
Error executing cl.exe.

Can anyone tell me whats wrong with the following line

if ( line.substr(index+6,1) == '1')

I've tried assigning the substr to a tmp string, then a char, casting it to a char. all have failed.

+++++++++++++++++++++++++

Additionally the line while(!netcsv.eof()) statemant causes an error. This has worked in a previous program with one major difference.

In the working program the code <ifstream netcsv(filename)> where filename was defined as an array of char. In this program it is defined as a string.

+++++++++++++++++++++++++

Thanks in advance for any help with these issues, most of the code is shown below.
I should point out that netData and the string header are defined in nt.h

Code:

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#include <c:\work\programming\nettest\nt.h>
#include <fstream>
#include <iostream>
//#include <string>
#include <sstream>

using namespace std;

netData readNetcsv()
{                       
        int index, startTime, timeStep, endTime, tmp;
        char answer, temp;
        string line, tstore, filename, path;
        bool marker = false, again = true;
        netData *lMember, *start_ptr, *end_ptr;                                                        //create object

        start_ptr = end_ptr = NULL;                                                                //init pointer to list
        do
        {
                cout << "Enter file path : " << endl;                                                //get path details
                cout << "(eg c:\\dir1\\dir2\\ " << endl;
                cin >> path;
                filename = path + "net.csv";                                                        //build full filename
                ifstream netcsv(filename.c_str());                                                //& open
                if (netcsv)                                                                                                        //process file
                {
                        cout << filename << " opened successfully " << endl;
                        istringstream strin (tstore);                                                //object constructor for int string ops
                        do
                        {
                                getline (netcsv, line);
                                if ((line[0] == 'T') && (line[1] == 'I'))                        //wait until colomn headers found
                                {
                                        marker = true;
                                        getline (netcsv, line);
                                }
                                if (marker == true)                                                //start saving data
                                {
                                        lMember = new netData;                                        //create new record
                                        index = line.find(",",1);                                //find first comma in line
                                        tstore = line.substr(0,index);                                //get time field
                                        strin >> lMember->time;                                        //save as integer variable
                                        tstore = line.substr(index+1,4);                        //probability now
                                        strin >> tmp;
                                        //or lMember->probability = strtod(tstore.c_str(), NULL);
                                        lMember->prob = (int)(tmp*100 + 0.5f);                        //convert to threshold value
                                        if ( line.substr(index+6,1) == '1')                        //alarm field
                                        {
                                                lMember->alarm = true;       
                                        }
                                        else
                                        {
                                                lMember->alarm = false;
                                        }
                                        lMember->nxt = NULL;
                                        if (start_ptr == NULL)                                        //manage pointers                                       
                                        {
                                                start_ptr = lMember;                                //first member in list
                                                start_ptr->path = path;                                //file path details
                                                end_ptr = start_ptr;
                                                startTime = lMember->time;                        //hold first time point
                                        }
                                        else
                                        {                                                               
                                                end_ptr->nxt = lMember;                                //set pointer for previous record
                                                end_ptr = lMember;                                //point to new end of list
                                                if (timeStep == 0) timeStep = lMember->time - startTime;
                                        }
                                }
                        }while(!netcsv.eof());
                        endTime = lMember->time;                                                //hold last time point
                        again = false;                                                                //another loop not required
                }
                else
                {                                                                                                                        //file doesn't exist
                        cout << "File not found. " << endl;
                        cout << "Enter new path y/n (y) : " << endl;
                        cin >> answer;
                        if (answer == 'n') again = false;                                        //allow prog to fail
                }
        }while(again);
        return (start_ptr);
}

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Opps - this info will probably help
<cpp(47) : error C2679> refers to <if ( line.substr(index+6,1) == '1')>

Quote:

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Originally Posted by spudval

Can anyone tell me whats wrong with the following line

if ( line.substr(index+6,1) == '1')

---

The problem is that you're comparing a string to a character. You can either do this:

Code:

---

if (line.substr(index + 6, 1) == "1")

---

Or even better, a substring of size 1 is just a character, so this will work too:

Code:

---

if (line[index + 6] == '1')

---

thanks again

I originally had the first sugesttion in the code, which also produced an error.
But good news the second did work

On to the next error.

Note that your check for eof() is not the best way to solve that problem. You don't handle fail states (which are admittedly rare when using getline) and the eof bit is not set until the read attempts to read past the end of the file (also somewhat rare with getline).

Ideally, you should check the return value of the read to verify that it worked, and then process the line you read in. For example, in your code instead of the do while loop, use a regular while that looks like this:

Code:

---

while (getline (netcsv, line))
{
  // all your code
}

---