c++ convert string to hex

Question

Possible Duplicate:
C++ convert hex string to signed integer

I allready searched on google but didn't find any help. So heres my problem: I have strings that allready contains hex code e.g.: string s1 = "5f0066" and i want to convert this string to hex. I need to compare the string with hex code i've read in a binary file.

(Just need the basic idea how to convert the string) 5f Best regards and thanks.

Edit: Got the binary file info in the format of unsigned char. SO its 0x5f... WOuld like to have teh string in the same format

Solution 1

Use std:stoi as (in C++11 only):

std::string s = "5f0066";
int num = std::stoi(s, 0, 16);

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Solution 2

Use stringstream and std::hex

std::stringstream str;
std::string s1 = "5f0066";
str << s1;
int value;
str >> std::hex >> value;

Solution 3

strtol(str, NULL, 16) or strtoul(str, NULL, 16) should do what you need.

strtol strtoul