从文本文件中提取字符串列表

Question

I am trying to extract a vector that contains all strings in a txt file using c++, which I have almost no experience. In java or matlab, this would have been really easy, all I have to do is

1. Read a long list of character sequence from the txt file.

2. Loop through this sequence and extract the strings.

In c++ there seems to be a lot more things that I have to deal with, for example, I am asked to

1. Add a new C++ header (.h) file to my program and in it please declare an enumeration for the different array indices that are relevant.

2. Declare a file parsing function that takes two parameters: a reference to a Standard Template library (STL) vector of C++ style strings (eg, of type vector &), and a C-style string (of type char *);

Non of these makes too much sense to me. Is there a good source to get help on this?

Answer 1

To read the file:

std::ifstream in("foo.txt");
std::stringstream buffer;
buffer << in.rdbuf();

After that there are various ways to split up the contents, depending on your exact requirements.

Answer 2

Since you are new to C++, I recommend you check out this website: http://www.cplusplus.com/

Parsing from input files is relatively easy if you are using command line to run your program. Simply include the main function as follows:

int main(int argc, char **argv)

Then, access the parameters passed in using argv as an array:

var = argv[0];

Declare a char array and then use that array to capture each line of the file.

char input[MAX_SIZE];
while(cin.getline(input, MAX_SIZE))
{
    //Each time this executes, input contains all characters of a line, like a string
    //e.g. make it a String and add it to a vector of type String
    //do something with input[]
}

Your file parsing function can receive the two parameters that I specified in the main parameters, but these must also be declared as parameters to main. Then, your function can grab the input the way I demonstrated.

As for your header file, I'm not exactly sure what kinds of enumerations you mean, but you can find syntax and rules for enumeration on the site given above. If I recall correctly, enumerations are similar in Java and C++.