[FunnyBear]

This should somehow give you an idea,

pawn Код:

new line[128]; //A string a 128 string cell (depending on the size of your file, change it)
    new File:filehandle = fopen("" /* << .txt file location/name */, io_read); // this will open the file
    while(fread(filehandle, line)) // This will read the file
    {
        // Your code here
    }
    fclose(filehandle); // Closes the file

Maybe you forgot the File: in the filehandle variable. It will be easier if you can give more code.