When you're reading a file, is there a way to tell what line you're currently reading.

Example:

0 The quick
1 brown
2 fox jumps
3 over the
4 lazy
5 d
6 o
7 g

If we were reading "lazy" then it would return 4 because that's the line that lazy's on.

I read about a function "tellg()" but I think that returns position in bytes not in lines.

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Make a counter per line and add the if statement before read()

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as HelloWorld said, the way to do it is to keep a counter for each call to getline() that you issue to the fstream.

"lines" as you probably know them are indicated by a '\n' (newline) character. When you open a file, your program has absolutely no idea which characters reside in your file until you actually read them - there's no built-in mechanism within the language which counts the number of '\n' characters automatically, so you have to do it yourself.
(since '\n' isn't really a special character, its just the same as any other character, as far as the language is concerned)

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That's what I was doing I was just wondering if there's a better way, thanks

Also, is there a way to advance to the next line through a function?

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Again, getline will do that for you. if you don't care about the rest of a line, then you could also do an ignore, instead of a getline into a dummy string. The principles and methods here are identical to the problem of the common "how do I empty cin", in that you're skipping all the remaining chars up to, and including the next newline character, except that you're reading a file stream (all streams in C++ are basically the same).

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Thanks once again Bench.

Again another question, is it possible to go backwards 1 line?
I've read about seekg but reading about it just went straight over my head.

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ummm... what do you mean by going backwards one line? what are you trying to do? if you want to make sure that you get one line back, then each time you read one line, store it in a temp variable before going to the next 2 lines..

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No, that's not possible. remember that a stream is not a file, but a "pipe" which acts as an input or output interface to/from a file. physical access to a file isn't supported by standard C++, since its O/S dependent (There might be some OS-specific libraries which do this). You're limited to the things which a stream can do - when you read from a stream, the bytes are removed from that stream, there's no 'going back', nor is there any built-in buffer which remembers anything that you've read from the stream (Though you could write one).

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Looks like I'll have to write one!

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I'm unfamiliar with C++, but can't you flush the buffer each time you read?

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