#include <iostream>
#include <fstream>
#include <string>
#include <conio.h>
using namespace std;

int main ()
{
  string line;
  int i = 0;
  long l,m;
  float perc;
      char *location;
        char string1[80], string2[80];
  int appearances = 1;
  ifstream myfile ("input.txt");
  
  
  if (myfile.is_open())
  {
        while (! myfile.eof() )
        {
              getline (myfile,line,'\t');
              cout <<line<<endl;
              l = myfile.tellg();
              myfile.seekg (0, ios::end);
              m = myfile.tellg();
    
        }
        
        if ( myfile == NULL )
            printf("No match was found.\n");
        else
            cout<<" was found at position", string2, location-string1;
    }
}     //<---- you were missing this closing bracket

char *strstri(char *t, char *s)
{

        int i, j;
        for(i=0; t[i] != '\0'; i++)
        {
                for(j=0; s[j] != '\0'; j++)
                {
                        if ( toupper(s[j])==toupper(t[i+j]) )
                            continue;
                        else
                            break;
                }
                    /*if the whole string was successfully compared, break the loop*/
                if (s[j] == '\0') break;
                {
                     if (s[j] == '\0')
                    return (i+t); /*returns a pointer to the first occurrence of s within t, just like the original strstr*/
                }
                else 
                {
                     getch();
                    return (0); /*return NULL*/
                }
          }
          //Im not sure if you wanted this inside the loop
         //or outside it
          getch();
          return 0;
} 

#include <iostream>
#include <fstream>
#include <string>
#include <conio.h>
using namespace std;

char *strstri(char *t, char *s);

int main ()
{
	string line;
	int i = 0;
	//long l,m;
	//float perc;
	char *location;
	char string1[80], string2[80];
	int appearances = 1;

	ifstream myfile ("input.txt");
  
	if (myfile.is_open())
	{
		while (! myfile.eof() )
		{
			getline(myfile,line,'\n');
			cout << line <<endl;

			// Convert our string to a c-string and dump
			// it into string1
			strcpy(string1,line.c_str());

			// Ok so lets search for "needle" in our string1
			location = strstri("needle",string1);

			// If it is not null, we found it, spit out
			// the match along with the rest of the line
			// (after all it is a pointer into the string)
			if (location != NULL) {
				cout << "Substring: " << location << endl;
			}
		}
	}

	getch();
	return 0;
}

char *strstri(char *t, char *s)
{
	int i, j;
	bool found = false;

	for(j=0; s[j] != '\0'; j++)
	{
		// First find if character in needle is same as haystack
		if (s[j] == t[0]) {

			// If first letter found, run through the rest of the
			// needle word.
			for(i=0; t[i] != '\0'; i++)
			{
				// While characters match and we are not at the end
				// of the haystack string, keep found true
				if ((s[j+i] != '\0') && (s[j+i] == t[i])) {
					found = true;
				}
				else { found = false; break; }
			}

			// If found is still true here, it means that the entire
			// needle string was found in the haystack string.
			// So return a char pointer to the substr start
			if (found) { 
				char *charptr = &s[j];
				return charptr; 
			}
		}
	}

	// We return null if the string was not found.
	return NULL; /*return NULL*/
}