Thread: 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:

#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);
}

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