My last regular expression won't work but i cannot figure out the reason why

Question

I have two vectors, one which holds my regular expressions and one which holds the string in which will be checked against the regular expression, most of them work fine except for this one (shown below) the string is a correct string and matches the regular expression but it outputs incorrect instead of correct.

INPUT STRING

.C/IATA

CODE IS BELOW

std::string errorMessages [6][6] = {
    {
        "Correct Corparate Name\n",
    },
    {
        "Incorrect Format for Corporate Name\n",
    }
};

std::vector<std::string> el;
split(el,message,boost::is_any_of("\n"));
std::string a = ("");

for(int i = 0; i < el.size(); i++)
{
    if(el[i].substr(0,3) == ".C/")
    {
        DCS_LOG_DEBUG("--------------- Validating .C/ ---------------");
        output.push_back("\n--------------- Validating .C/ ---------------\n");
        str = el[i].substr(3);
        split(st,str,boost::is_any_of("/"));
        for (int split_id = 0 ; split_id < splitMask.size() ; split_id++ )
        {
            boost::regex const string_matcher_id(splitMask[split_id]);
            if(boost::regex_match(st[split_id],string_matcher_id))
            {
                a = errorMessages[0][split_id];
                DCS_LOG_DEBUG("" << a )
            }
            else
            {
                a = errorMessages[1][split_id];
                DCS_LOG_DEBUG("" << a)
            }
                output.push_back(a);
        }
    }
    else
    {
        DCS_LOG_DEBUG("Do Nothing");
    }

st[split_id] = "IATA"

splitMask[split_id] = "[a-zA-Z]{1,15}" <---

But it still outputs Incorrect format for corporate name

I cannot see why it prints incorrect when it should be correct can someone help me here please ?

Answer 1

Your regex and the surrounding logic is OK.

You need to extend your logging and to print the relevant part of splitMask and st right before the call to boost::regex_match to double check that the values are what you believe they are. Print them surrounded in some punctuation and also print the string length to be sure.

As you probably know, boost::regex_match only finds a match if the whole string is a match; therefore, if there is a non-printable character somewhere, or maybe a trailing space character, that will perfectly explain the result you have seen.