CODEWITHSUNDEEP
c++visual-c++stringstream
satyanarayana
satyanarayana

Reputation: 379

How to replace some characters from stringstream in C++?

I have a requirement to replace all the carriage returns/ Line feeds from a stringstream in a VC++ Project. I am very new to this and I tried the following:

strCustData.Replace("\r\n","")

But this is not working because strCustData is of type stringstream, not string. Please help me out in achieving this.

Upvotes: 3

Views: 7078

Answers (3)

David G
David G

Reputation: 96810

You probably want to use a stream buffer to filter out the characters:

class filter : public std::streambuf
{
public:
    filter(std::ostream& os) : m_sbuf(os.rdbuf()) { }

    int_type overflow(int_type c) override
    {
        return m_sbuf->sputc(c == '\r' ? traits_type::eof() : c);
    }

    int sync() override { return m_sbuf->pubsync() ? 0 : -1; }
private:
    std::streambuf* m_sbuf;
};

Now you can use it like this:

filter f(strCustData);
std::ostream os(&f);

os <<"\r\n"; // '\n'

Upvotes: 4

Iosif Murariu
Iosif Murariu

Reputation: 2054

An ugly (memory duplicating because of using a std::string as buffer) way to do it is something like this:

// replace "foo" with "bar"
std::stringstream myStringStream("foobarfoobar");
std::string myString(myStringStream.str());

size_t start = 0;
while ((start = myString.find("foo", start)) != std::string::npos) {
    myString.replace(start, strlen("foo"), "bar");
}
myStringStream.str(myString);

Upvotes: 2

graham.reeds
graham.reeds

Reputation: 16476

You need to convert the stringstream into a std::string - not CString like you seemingly tried to. std::string has lots of functions that can be used to manipulate the characters.

Something like this (untested):

std::istringstream stream;
std::string str(stream.str());
std::replace(str.begin(), str.end(), '\r', ' '); 
std::replace(str.begin(), str.end(), '\n', ' ');

You could probably collapse the two replaces into one, but I am writing off the top of my head.

Upvotes: 1

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