Reading lines in file

smock (3)
Hello,

I'm running a program that reads lines from files. The program gets the total length of the file using the push_back container.
however, I'm trying to read the particular lines of a file.

If a line beginning with some character is encountered, I want to get the line number that that character was found.

I'm not sure how to go about it.

Please help!
hamsterman (4538)
pseudocode
file = open ...
line_counter = 0
while there are things to read
   str = getline(file)
   line_counter ++;
   if some_function(str[0]) == true 
   then cout << "found " << str << " on line " << line_counter << ", starting with " << str[0] << '\n';
Which part of that is not clear?
smock (3)
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line_counter = 0;
 while(getline(myfile,line)){
         line_counter++;
          printf("%s\n", line); 
          lines.push_back(line);
          printf("%i", lines.size());
          istringstream isline(line);
          if (isline>>ch)
          {  
            switch (ch)
            {
                case 'A':
                {
                    int input;
                    isline>>input;
                    cout<<line_counter<<'\n';
                   
                }
                break;
                case 'B':
                {
                    int input;
                    isline>>input;
                    cout<<line_counter<<'\n';
                   
                }
                break;


The above is a snippet of my code. I have various switch statements for which I need to read the line. I'm still not getting the line number. Please help me.
Last edited on
hamsterman (4538)
What are you getting then?

printf only works when the string is a char*, while you have an std::string. You could use line.c_str(), but there is no point in mixing c and c++ io libraries at all. It's ugly. Just do cout << line;
bluecoder (763)
I think we have to read every line .. but we print the line number and that particular line .

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FilePtr file = open ...
int line_counter = 0
cout<<"Enter the particular string like 'Something' that you want to search in the file  "
cin>>findstr ; 
while( !file.eof())
{
   if(getline(file).find(findstr))
	{
		cout<<"\n String present in the line "<<	line_counter ++;
		cout <<"\n "<<file;

	}
   if some_function(str[0]) == true 
   then cout << "found " << str << " on line " << line_counter << ", starting with " << str[0] << '\n';
}


please let me know if i am wrong .
smock (3)
hamsterman's method actually works. some variables in my program were throwing it off. Thanks for your help.
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