Getting a substring in C

I have a string in the following format: "R: 625.5m E:-32768m"

What's the most efficient开发者_如何转开发 way to pull out the 625.5?

Your best bet is to use sscanf to read formatted information from the string.

sscanf(mystr, "R: %f", &myFloat);

sscanf is a good candiate to parse simple strings with fixed format.