how can i resolve this issue of fread command

plz help me out i m recieving this error, dont know what it means and how to resolve it, have tried different versions of matlab and recieved same error this code executed successfully just once now this error is visible

"name=uigetfile('*.*');
file_open=fopen(name,'r');
file_read=fread(file_open,'uint8');
fclose(file_open);
a=file_read;"

*_Error using fread Invalid file identifier. Use fopen to generate a valid file identifier.

Error in bwtenc (line 4) file_read=fread(file_open,'uint8');_*

Answer 1

[michael scheinfeild]

openonly one file at time , see if the file name is correct

fid = fopen("fname.txt","rt")
data=fread(fid,inf);% of data= fscanf
fclose(fid)

if it is binary open by fid=fopen("fname.bin","rb")

[tauqeer]

brother i m opening only one file + file name is also correct have executed this code it had just worked once now i m recieving error.

[Walter Roberson]

MATLAB opens in binary unless you use the 't' flag. This is opposite of C's convention.

Answer 2

[Walter Roberson]

[filename, filepath] = uigetfile('*.*');
name = fullfile(filepath, filename);
file_open = fopen(name, 'r');
file_read = fread(file_open,'uint8');
fclose(file_open);
a = file_read;

My guess is that one of the times you were already in the correct directory and the other times you were in a different directory than where your files were located.