huge string-pointer problem

[MKashlev]

Hello,
I have a big problem with pointers and strings -- it seems that I cannot compare string with another string. In the code snippet below, i am trying to compare normal. with whatever value is in the word variable at the moment. If there is a "normal." then the script ouputs 0, if not, then an 1.

The problem is that where the script should output 0, it outputs 1. And where there it should output 1, it outputs 1 (no problem here).

The code deals with the input of many lines, each line having 42 fields separated from each other by comma. The code finds the 42nd field which contains either normal. value or any other word with dot at the end.

What should I do? Please help ASAP: please answer on the same day this message was posted.

        for(a=0; !infile.eof();){
// read in one line
                char *p;
                char word[20] = "";
                infile.getline(buff,200);
                p = strtok(buff,",");
                for(int i=0; i<42; i++)
                {
                        if(i==41)
                        {
                                strcpy(word,p);

                                if (word=="normal.")
                                {
                                        cout<<"0";
                                        outfile<<"0";
                                }
                                else
                                {
                                      cout<<"1";
                                      outfile<<"1";
                                }
                        }

                        p = strtok(NULL,",");
                }
                cout<<endl;
                outfile << endl;
                a++;
        }

[hk_mp5kpdw]

You need to use to use the strcmp function to compare character strings in the manner you are attempting. You can do it the way you have it in your sample if you use string objects as variables instead of character arrays.

[MKashlev]

thanks alot!

[LuckY]

Just wanted to elaborate a little bit on why you can't use the == operator to compare null-terminated char*s.

What's commonly known as a string is actually a char* which is a pointer to an array of chars (of course with a null byte to end the string).
When you do something like:
char *a = "aaa";
char *b = "bbb";

if (a == b) ...

you are saying "if the address that a points to is equal to the address that b points to..." which of course is not what you want to ask.

what the strcmp() function does is step through each character of both arrays and does a one-to-one comparison until they are determined as not equal or until they are