NIOS II processor Not responding

hello,

I have DE2-70 board and I need to read a data file from my pc and write

it into sdram for further processiong this data.I am using following code

to open a file.but it is not working .

# include <stdio.h>

int main()

{

FILE * pFile;

char mystring [100];

pFile = fopen ("c:\myfile.txt" , "r");

if (pFile == NULL) perror ("Error opening file");

else {

fgets (mystring , 100 , pFile);

puts (mystring);

fclose (pFile);

}

return 0;

}

I have also tried a template'host file system '

but for all file related functions error is like..

undefined reference to fopen etc.

please help me.