Spliting strings?

I was making a console type program, but the only part im stuck on is spliting the commands that the user inputs. For example. Lets say the user inputs--"exec C:/blah.exe". I wan't to split "exec", and "C:/blah.exe" apart. Some function kinda like this.

split(buffer, string, delimiter);

Also, is it possible to make the buffer an array of somesort, so it puts the first part in buffer[0] which would be "exec", and buffer[1] would contain "C:/blah.exe";

I don't know of any such functions, but if you could point me in the right direction then I would greatly appreciate it!

Try one of the online C/C++ references.

In C I would use strchr() or strtok(), but unfortunately I don't know the C++ equivalent.

I'm used to using Split in VB applications. I found this code where the join and split were ported over.

http://www.codetoad.com/c_join_split.asp

I use the code in a c+ program and it's great.

Quote:

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Originally Posted by dwks

Try one of the online C/C++ references.

In C I would use strchr() or strtok(), but unfortunately I don't know the C++ equivalent.

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I have a feeling im gonna be making my first gigantic function.

Why? Try strtok().

strtok().

Or, better yet, try here and look at find or something.

Looking into strtok. Thanks! Ill tell you how it works out.

Ok, well the only problem I have is since im using strings in my prog I use c_str(); to convert them into const char*, but this strok function want's char* instead of const char*. Any ideas?

Copy the const char* into a buffer, and use the buffer as an argument to strtok().

Or use the C++ function[s] (which I don't know about yet).

Quote:

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Originally Posted by dwks

Copy the const char* into a buffer, and use the buffer as an argument to strtok().

Or use the C++ function[s] (which I don't know about yet).

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Hmm, well I wonder if there are any alternatives to c_str().
I don't like the fact that it assumes that your never gonna change the value of that string.

Use either a stringstream or a combination of find and substr. The stringstream works just like cin and can parse your string easily (use getline with your delimiter if you have only one). The substr method of the C++ string class can get a substring from the original like Left, Mid, or Right.

You don't want to use the C string methods with C++ strings because they weren't designed for that. Use the C++ methods, or make a C-style copy of the string if you really want to use strtok.

This looks right to me. Note that charInput is an std::string. I also didn't post all of the code since it is quite large, and these are the only 2 functions you really need to see.

Code:

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void CTextFunc::getInput()
{
        ba("");
        std::getline(cin, charInput);
        if(boolInputLimit==true){
                if(strlen(charInput.c_str())<=usintCharInputLimit){
                exec(charInput.c_str());
                getInput();
                } else {
                ban("Error! Your command is to long!");
                ba("The maximum amount of character's allowed is \'");
                sprintf(charIntBuffer, "%i", usintCharInputLimit);
                b(charIntBuffer);
                bn("\'");
                getInput();
                }
        } else {
                exec(charInput.c_str());
        }
}

void CTextFunc::exec(const char* charString)
{
        strtok (charString," ");
        getInput();
}

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Of course the exec function doesn't work since charString is is a const char*, and I can't figure out how to convert it into a char*. Could you show me an example with using strtok then?

Code:

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char newbuffer[strlen(charString)+1];
strcpy(newbuffer, charString);

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Or use C++ functions.

A stringstream would be ideal here - and much simpler than your current code. There are a lot of existing string functions that you aren't taking advantage of. For example, there is no need to use strlen with a C++ string. It has a length() method.

BTW, using dwks code above to copy a C++ string into a C style string needs to be strcpy(newbuffer, charString.c_str());

Quote:

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using dwks code above to copy a C++ string into a C style string needs to be

Code:

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strcpy(newbuffer, charString.c_str());

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Code:

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void CTextFunc::exec(const char* charString)

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It does? :)

[edit]dwks' code:

Code:

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strcpy(newbuffer, charString);

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[/edit]

Quote:

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Originally Posted by Daved

A stringstream would be ideal here - and much simpler than your current code. There are a lot of existing string functions that you aren't taking advantage of. For example, there is no need to use strlen with a C++ string. It has a length() method.

BTW, using dwks code above to copy a C++ string into a C style string needs to be strcpy(newbuffer, charString.c_str());

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Sorry if this is asking to much, but could you show me an example of using stringstream. Iv been going by what everyone tell's me, and I always get shifted in diffrent directions.

>> It does?

You got me there. Sorry.

>> Sorry if this is asking to much, but could you show me an example of using stringstream. Iv been going by what everyone tell's me, and I always get shifted in diffrent directions.

Different people have their own ways of doing things which unfortunately makes it confusing. You just need to try to understand what's going on as much as possible and make the decision on what sounds like the best way to go.

here is an example using stringstreams. Compile it and run it to see what is going on:

Code:

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#include <iostream>
#include <sstream>
#include <string>
 
int main()
{
        std::string line = "This is a line of text.";
        std::istringstream istrm(line);
        std::string word;
        while (istrm >> word)
                std::cout << word << std::endl;
        std::cout << "---Done---" << std::endl;
 
        line = "This,is,a,line,of,text,with,commas";
        istrm.clear();
        istrm.str(line);
        while (getline(istrm, word, ','))
                std::cout << word << std::endl;
        std::cout << "---Done---" << std::endl;
 
        line = "A Number is 13.5";
        istrm.clear();
        istrm.str(line);
        istrm >> word;
        std::cout << word << std::endl;
        istrm >> word;
        std::cout << word << std::endl;
        istrm >> word;
        std::cout << word << std::endl;
 
        double number;
        istrm >> number;
        std::cout << number + 1.0 << std::endl;
 
        std::cout << "---Done---" << std::endl;
}

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theres always boost::tokeniser you can get it at here

Quote:

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Different people have their own ways of doing things which unfortunately makes it confusing. You just need to try to understand what's going on as much as possible and make the decision on what sounds like the best way to go.

here is an example using stringstreams. Compile it and run it to see what is going on:directions.

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Ok thanks, but there's one little part im confused. Where you have

Code:

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std::istringstream istrm(line);

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I understand thats a case for the istringstream class, but whats with the (line) part? Sorry if this is a stupid question :(. I bought a 1000 page book "Sam's Teach Yourself C++ in 21 Days". It wasn't specific on these topics.

When you construct an input string stream, it should have some data in it to extract into your variables. It's just like an ifstream that has the data in the file that can be extracted into variables. The constructor of the istringstream takes a string that you will parse. So I created an example string to parse ("This is a line of text.") and passed that string to the constructor of the istringstream. So now the istringstream is loaded with that string and you extract data out of it just like it was a file with that data inside it.

Notice later I called istrm.str(line). This basically does the same thing, except it is for a stream instance that has already been constructed. It resets the internal contents of the stream to whatever line holds.

If you understand file streams, just think of a stringstream as the same thing, except instead of an actual file on disk, there is just a big string in memory that holds all the data and can be accessed bythe str() method.