Question

i am new to C++. I would like to know how do i create a function to check for delimiter.

such as the case below

AD,Andorra,AN,AD,AND,20.00,Andorra la Vella,Europe,Euro,EUR,67627.00
AE,United Arab Emirates,AE,AE,ARE,784.00,Abu Dhabi,Middle East,UAE Dirham,AED,2407460.00
AF,Afghanistan,AF,AF,AFG,4.00,Kabul,Asia,Afghani,AFA,26813057.00

If the delimiter become $ or # instead of comma , how do i create a function to check for it and say , wrong format of text file.

Thanks!

Below is my readData code

void readData ()
{
    FILE * pFile;
    NoOfRecordsRead = 0;
    char buffer [Line_Char_Buffer_Size];

    pFile = fopen (INPUT_FILE_NAME , "r");

    if (pFile == NULL) 
        perror ("Error opening file 'Countries.txt' !");
    else
    {
        while ( !feof (pFile) )
        {
            char* aLine = get_line (buffer, Line_Char_Buffer_Size, pFile);

            if (aLine != NULL)
            {
//              printf ("%d] aLine => %s\n", NoOfRecordsRead, aLine);
                globalCountryDataArray [NoOfRecordsRead++] = createCountryRecord (aLine);
            }
        }

     fclose (pFile);

    }
}

Answer 1

#include <string>
#include <fstream>
#include <algorithm>

bool detect_comma(std::string file_name)
{
    // open C++ stream to file
    std::ifstream file(file_name.c_str());
    // file not opened, return false
    if(!file.is_open()) return false;
    // read a line from the file       
    std::string wtf;
    std::istream &in= std::getline(file, wtf);
    // unable to read the line, return false
    if(!in) return false;
    // try to find a comma, return true if comma is found within the string
    return std::find(wtf.begin(), wtf.end(), ',')!= wtf.end();
}


#include <iostream>
#include <cstdlib>

int main()
{
     if(!detect_comma("yourfile.dat"))
     {
         std::cerr<< "File is not comma delimited!\n";
         return EXIT_FAILURE;
     }
     // file is OK, open it and start reading
}

Edit: Added comments & example code