This function will detect known languages based on the kind of Morrowind gamedata is being fed to it

openmw_language_detection.c

/* Written by Michael Dec <grepwood@sucs.org>
 * Language detection of Morrowind gamedata
 */
 
structure LDesc_struct
{
	unsigned char code;	/* Fingers crossed Morrowind wasn't translated to more than 255 languages */
	char desc[32];		/* 32 bytes in the .esm that indicate what language this is */
};

/* The descriptions are like this because their character form is subject to character encoding.
 * If we compare the numbers, then we will never get wrong results because of different encoding.
 */

LDesc_struct English = {{1},{84,104,101,32,109,97,105,110,32,100,97,116,97,32,102,105,108,101,32,70,111,114,32,77,111,114,114,111,119,105,110,100}};
LDesc_struct Polish = {{2},{80,108,105,107,32,103,179,243,119,110,121,32,100,108,97,32,103,114,121,32,77,111,114,114,111,119,105,110,100,46,0,0}};

#define LCOUNT 2

char * DLanguage[LCOUNT] = {English.desc,
							Polish.desc};
unsigned char * CLanguage[LCOUNT] = {	English.code,
										Polish.code};

unsigned char GameLanguage(FILE * esm) {
	char Description[32];
	unsigned char count;
	unsigned char result = 0;
	int compresult;
	fopen(esm,"rb");
	fseek(esm,64,SEEK_SET);
	fread(&Description,32,1,esm);
	fclose(esm);
	for(count = 0; count < LCOUNT, compresult; ++count) {
		compresult = memcmp(Description,DLanguage[count],32);
	}
	if(!compresult) {
		result = CLanguage[count];
	}
	return result;
}

/* If return is 0 then the function failed to detect the language */