C++ Carriage return and line feed in a string

Question

I am working with the communication for some TCP/IP connected equipment in C++. The equipment requires that the commands sent are ended with 
. I am using a configuration file from which I am reading the commands used in the communication. The problem I have is that the commands 
 are interpreted as the 4 characters they are and not as carriage return and line feed. I have tried to use the string.data() but I get the same result as string.c_str(). Is there any nice function to get it correct from the beginning or do I have to solve this with a normal replace function? Or some other way that I have not thought about? I guess, if I don't find a really neat way to do this I will just omitt the 
 in the configuration file and add it afterwards, but it would be nice to have it all in the configuration file without any hard coding. I think I would need to do some hard coding as well if I would try to replace the four characters 
 with their correct characters. Thanks for any hel…

Accepted Answer

If the data in the configuration file requires translation, you have to translate it. Short of regular expressions (which are clearly overkill for this), I don't know of any standard function which would do this. We use something like:

```
std::string
globalReplace(
    std::string::const_iterator begin,
    std::string::const_iterator end,
    std::string const& before,
    std::string const& after )
{
    std::string retval;
    std::back_insert_iterator<std::string> dest( retval );
    std::string::const_iterator current = begin;
    std::string::const_iterator next
            = std::search( current, end, before.begin(), before.end() );
    while ( next != end ) {
        std::copy( current, next, dest );
        std::copy( after.begin(), after.end(), dest );
        current = next + before.size();
        next = std::search( current, end, before.begin(), before.end() );
    }
    std::copy( current, next, dest );
    return retval;
}
```

for this. You could call it with `"\r\n", "
"` for the last to arguments, for example.

C++ Carriage return and line feed in a string

Solution

Problem