Reading a file word by word with no ending chars

I have this small program in C that reads through a file and compares word by word, how can I assure that strings like "this," won't be read as a word? I would like it to read as "this"

if(argc != 3)
{
    printf("Usage: ./sw <word> <filename> \n");
    exit(1);
}

char* word = argv[1];
const char* filename = argv[2];

FILE* file = fopen(filename, "r");
if(file == NULL)
{
    printf("Could not open file\n");
    exit(1);
}

//Assuming one word can not have more than 250 chars
char w[250], check_eof;

do 
{
    check_eof = fscanf(file, "%s", w);
    if(strcmp(word, w) == 0)
    {
        printf("W : %s \n", w);
    }
} while(check_eof != EOF);

fclose(file);

return 0;