position = ftell(fid)
position = ftell(fid) returns the location of the file position indicator in the specified file. position is indicated in bytes from the beginning of the file. fid is a integer file identifier obtained from fopen.
The value of position is a nonnegative integer if the query is successful. If -1 is returned, it indicates that the query was unsuccessful; use ferror to determine the nature of the error.
fopen,fclose,ferror,fread,fwrite,fseek,fprintf,sprintf,fscanf,sscanf
(c) Copyright 1994 by The MathWorks, Inc.