Extract Title from plain text file

I am writing a program that basically works like Project Gutenberg. What this does is it takes plain text files as input and outputs these text files in HTML format. I am just beginning the project and have started by trying to extract the title from a file. What I know is that the title ALWAYS begins with "Title:" and only lasts the line that "Title:" is on. I have written code but it doesn't work (of course, that's why I came here!"). To me, my code seems logically correct but it just doesn't run. Any help would be appreciated.

getTitle() function:

Code:

---

string Book::getTitle(string title)
{
    size_t pos;

    pos = title.find("Title:");

    title = title.substr(pos);
    if(title.find("Title:"))
    {
        return title;
    }
    else
        return "";
}

---

Process book to store title in variable:

Code:

---

Book::Book(std::istream& in)
{
    std::string title, line;
    string::size_type start = 0;

    getline(in, line);
    while(in)
    {
        if(title[start] == ' ')
        {
            getline(in, line);
        }
        else
        {
            title = getTitle(line);
            break;
        }
    }
}

---

Code:

---

string Book::getTitle(string title)
{
    size_t title_start;
    size_t title_end;

    title_start = title.find("Title:");
    title_end = title.find("\n");

    if ( title_start == title.npos || title_end == title.npos )
      return "";
    title = title.substr(title_start, title_end);
    return title;
}

---

I may be wrong, but I think that is right.

edit: I can't remember if getline discards the '\n' character or not.

hmm it compiles and runs but doesn't print any title. It just prints a bunch of empty lines.

What does the file look like that you are parsing. Then maybe I can come up with a better solution?

edit: also if the file isn't very big then you could just load the entire thing into memory, then do searches that way. (by big I mean over 10 megabytes )

Well I just made a really simple text file to test this theory. But the actual test files are going to be much much bigger. Here is the test I am using:

Code:

---

dfghdfg
dfghdfgh
dfghdfgh
Title: This, should work

This is a test.
We want to see what happens.
Awesome.

---

Try changing this line

Code:

---

if(title[start] == ' ')

---

to

Code:

---

if ( title.empty() )

---

and use this getTitle instead

Code:

---

const string& Book::getTitle(string title)
{
    size_t title_start;

    title_start = title.find("Title:");

    if ( title_start == title.npos  )
      return "";
    title = title.substr(title_start);
    return title;
}

---

as I am pretty sure std::getline() discards the delimiting character.

It's still printing blanks :(

> It just prints a bunch of empty lines.
Why do you call .find() for the same thing twice?

Especially since you've already removed the string you're looking for.

I don't see where I do that?

pos = title.find("Title:");
title = title.substr(pos);
if(title.find("Title:"))
These?

Is the 2nd find ever going to succeed?

Try a test file with
Title: OK, does this Title: count

Quote:

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Originally Posted by Salem

pos = title.find("Title:");
title = title.substr(pos);
if(title.find("Title:"))
These?

Is the 2nd find ever going to succeed?

Try a test file with
Title: OK, does this Title: count

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Ahh that's right. Sorry, simple mistake. Got it working! Thanks a lot.