What should I use instead of sscanf?

Question

I have a problem that sscanf solves (extracting things from a string). I don't like sscanf though since it's not type-safe and is old and horrible. I want to be clever and use some more modern parts of the C++ standard library. What should I use instead?

Answer 1

Try std::stringstream:

#include <sstream>

...

std::stringstream s("123 456 789");
int a, b, c;
s >> a >> b >> c;

Answer 2

For most jobs standard streams do the job perfectly,

std::string data = "AraK 22 4.0";
std::stringstream convertor(data);
std::string name;
int age;
double gpa;

convertor >> name >> age >> gpa;

if(convertor.fail() == true)
{
    // if the data string is not well-formatted do what ever you want here
}

If you need more powerful tools for more complex parsing, then you could consider Regex or even Spirit from Boost.

Answer 3

If you include sstream you'll have access to the stringstream classes that provide streams for strings, which is what you need. Roguewave has some good examples on how to use it.

Answer 4

If you really want not to use streams (It's good because of readability), you can use StringPrintf.

You can find its implementation in Folly:

https://github.com/facebook/folly/blob/master/folly/String.h#L165

Answer 5

fgets or strtol