c++ making sure string is correct

What are the acceptable characters ?

Or strcspn if you want the inverse (ie. you have a list of unacceptable characters) :

        http://www.cplusplus.com/reference/clibrary/cstring/strcspn.html

std::string str;              // <--- the string that needs to be checked
std::string exclude;          // <--- all UNacceptable characters
if (strcspn(str.c_str(), exclude.c_str()) == str.length()) {
  // OK
}
else {
  // NOT OK
}

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Or if you can use any of the standard ctype functions :

        http://www.cplusplus.com/reference/clibrary/cctype/

like for example isprint (which returns true if the character is printable - ie. no control character) ...

You can use find_first_of and find_first_not_of std::string members to include or exclude specific chars from a string. You search for what you do or don't want included and take appropriate action if something is found.

http://www.cplusplus.com/reference/string/string/find_first_of.html
http://www.cplusplus.com/reference/string/string/find_first_not_of.html

is the strcspn case sensitive?
Or will I have to list out all upper case and lower case

Or use the C++ standard algorithms, like find_first_of for example :

        http://www.cplusplus.com/reference/algorithm/find_first_of.html

std::string str;              // <--- the string that needs to be checked
std::string exclude;          // <--- all UNacceptable characters
std::string::iterator it = find_first_of(str.begin(), str.end(), exclude.begin(), exclude.end());
if (it == str.end()) {
  // OK
}
else {
  // NOT OK
}

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or ... do you want me to keep going ? ;)


>> is the strcspn case sensitive?
>> Or will I have to list out all upper case and lower case

You will have to list them all. But as I said, if you just want to check for alphabetic characters, take a look at isalpha :

        http://www.cplusplus.com/reference/clibrary/cctype/isalpha.html

wow..thanks.. I 'll give your suggestions a try.