Issues with searching for a keyword in a file

[jahkyah]

Hi!

I am having issues with my search function to find a song for a play list maker I am creating. I have looked at the tutorials but I do not think I understand it.

Any help at all would be appreciated!

Thanks!

 void Keyword() 
{
	Playlist.open("Playlist.txt", ios::in);
	string stream;
	string line;
	string songName;
	bool found = true;

	cout << "Please enter in the name of a song.";
	cin >> songName;
	while (getline(Playlist , line))
	{
		found = true;
		if(found = (line.find(songName)))
		{
		cout << songName << "Has been found: \n";
		}
		
	}
cout << songName << " not found" << endl;
}

[wildblue]

line 14 - if you're checking for equality, use == instead of the assignment operator =

[jahkyah]

I am afraid that did not do it, but I think I am messing up on line 14 somewhere.

It is skipping to line 20 and says my name is not found.

[Chervil]

Something like this perhaps

    if (line.find(songName) != string::npos)
    {
        cout << songName << "Has been found: \n";
    }

see return value of string::find
http://www.cplusplus.com/reference/string/string/find/

[jahkyah]

I think I am on to something. When I type something in, I still do not get any results. But I am also thinking that I am needing to include the song length as well sense the getline is trying to find the exact match of my search.
Is this correct?

IE

Enter song name: Ryan
Enter song Length: 2

I am thinking that I need to include the 2 as well in my search? Do I understand correctly?

[Chervil]

Please give an example of the contents of "Playlist.txt" which you are trying to match that name "Ryan".

[jahkyah]

Sure thing!

Ryan
Will

Sorry for the confusion, I am just using simple names so I can get the search right.

EDIT:
If you need the whole code:

#include <iomanip>
#include <cmath>
#include <iostream>
#include <string>
#include <fstream>


using namespace std;
fstream Playlist("Playlist.txt", ios::out | ios::in);


/* musicTimeVerify(double songTime)
{
if (songTime <= 0)
{
cout << "Incorrect Time format. Please try again!";
}
else
return 1;
}
*/
void Songplaylist(double songTime, int numSong, string musicName)
{
	cout << "How many songs are you entering?: ";
	cin >> numSong;
	Playlist.open("Playlist.txt", ios::out);
	for (int i = 1; i <= numSong; i++)
	{
		cout << "Please enter your music name and THEN the song length in minutes" << endl;
		cout << "Song name (Enter an _ for spaces):";
		cin >> musicName;
		Playlist<< musicName;
		Playlist << endl;
		/*cout << "Song Length (in minutes please): ";
		cin >> songTime;

		Playlist << " : " << songTime << endl;
		//	musicTimeVerify(songTime);
		*/
	}
	cout << "Now closing the playlist..." << endl;
	Playlist.close();
}
void SaveData()
{
	string line;
	ifstream Playlist("Playlist.txt");

	if (Playlist.is_open())
	{
		while (getline(Playlist, line))
		{
			cout << line << endl;
		}
	}
	cout << "Reached the end of File" << endl;
	Playlist.close();
}

void Keyword() 
{
	Playlist.open("Playlist.txt", ios::in);
	string stream;
	string line;
	string songName;
	bool found = true;

	cout << "Please enter in the name of a song.";
	cin >> songName;
	if (line.find(songName) != string::npos)
	{
		cout << songName << "Has been found: \n";
	}
cout << songName << " not found" << endl;
}

int main()
{
	char choice = 'Y';
	int numSong = 0;
	string token;
	string musicName;
	double songTime = 0;
	int selection = 0;
	bool cont = true;
	cout << "_______________________________________________________________________________" << endl;
	cout << "Welcome to the Music Playlist program. \nPlease enter in a number for the following:" << endl;
	cout << "1.View playlist" << endl;
	cout << "2.Search for a Song" << endl;
	cout << "3.Delete playlist" << endl;
	cout << "4.Create a new playlist" << endl;
	cout << "5.Exit the program" << endl;
	cout << "_______________________________________________________________________________" << endl;
	while (cont == true)
	{
		cout << "Selection: ";
		cin >> selection;
		switch (selection)
		{
		case(1):
			SaveData();
			break;
		case(2):
			Keyword();
			break;
		case(3):
			Playlist.close();
			if (remove("Playlist.txt") != 0)
				perror("Error in deleting File...");
			else if (cout << "Successful Deletion of the Playlist");
			cout << endl;
			system("pause");
			break;
		case(4):
			cout << "A new playlist has been created." << endl;
			cout << "Would you like to edit the playlist now? Y/N:";
			cin >> choice;
			if (choice == 'y' || choice == 'Y')
			{
				cout << "You are now editing your new playlist." << endl;
				Songplaylist(songTime, numSong, musicName);
			}
			else
				break;
		case(5):
			cont = false;
			cout << "\nGood bye!\n";
			system("pause");
			break;
		}
	}
}

[Chervil]

I think the file was not opened properly. Rather than using a global variable. I used a local ifstream inside the function:

void Keyword() 
{
    ifstream Playlist("Playlist.txt");
    if (!Playlist)
    {
        cout << "Playlist file not open\n";
    }
    
    string line;
    string songName;

    cout << "Please enter in the name of a song.";
    cin >> songName;
    bool found = false;
    while (getline(Playlist, line))
    {
        if (line.find(songName) != string::npos)
        {
            found = true;
            cout << songName << "Has been found: \n";
        }
    }
    
    if (!found)
        cout << songName << " not found" << endl;
        
}

[jahkyah]

Ah, I did not think about the file being opened improperly, I thought I had done so in Line 3 of my first post.

Thanks for the advice!

Marking as solved.

[Chervil]

Ah, I did not think about the file being opened improperly, I thought I had done so in Line 3 of my first post.

When you posted the full code, at line 10 you had this:

fstream Playlist("Playlist.txt", ios::out | ios::in);

which would open the file for input/output at the start. Since that fstream is already open, trying to open it again in function Keyword() is not a good idea.

Though using a global constant for the file name might be a good idea

const std::string filename = "Playlist.txt";

so it can be used throughout the program, having global variables (such as the fstream Playlist) is not a good idea, because one is never certain in what state some other part of the program might have left it. Having uncertainty in a program design is not a good idea, so use local variables instead.