Depends by what you want to do exactly.
First let's see how to read the file after having called fopen():
- line per line:
char buff[1024];
while(fgets(buff, sizeof(buff), datei)) {
// buff will contain also the carriage return and the line feed used in the file
}
fclose(datei);
- all in memory:
struct stat xstat;
char *buff;
fstat(fileno(datei), &xstat);
buff = malloc(xstat.st_size + 1);
fread(buff, xstat.st_size, 1, datei);
buff[xstat.st_size] = 0;
fclose(datei);
Then, for the visualization you can use a MessageBox which is NOT an elegant solution but it's very simple, or you need to create a window in which visualizing this text (like I did in the message window of my q3dirtrav proof-of-concept).
An useful tutorial about the programming of the Windows gui is available here:
http://winprog.org/tutorial/