hi all, I am trying to open a file with .001 extension , fopen gives error. can you please help?

I am using d=dir(*.001), and can see file name (abcd.001) from name=d.name but fid1=fopen(name) returns negative value.

[KSSV]

Are you sure that there is only one file having name 001 in it? What is length(d)?

[Walter Roberson]

There might be a character that is not obvious, or it might be (for example) .OO1 instead of .001 . Try

[fid, msg] = fopen( d(1).name );
if fid < 0
   error('Failed to open because: "%s"', msg);
end

[perveen ali]

@KSSV yes i have only one file in the dir

[James Tursa]

I assume you meant to type d=dir('*.001') with the single quotes? Works for me PCWIN R2011a:

>> d=dir('*.001')
d = 
       name: 'abcd.001'
       date: '24-May-2017 09:00:35'
      bytes: 16
      isdir: 0
    datenum: 7.3684e+005
>> d.name
ans =
abcd.001
>> fid = fopen(d.name)
fid =
     3

Answer 1

[Jan]

fopen replies -1, if the name is a folder.

[perveen ali]

i think there was some issue with folder. I copied file to the same folder where my code is and it works fine now. thanks.

[perveen ali]

but this is not the solution for me. how can I open a subfolder and read *.001 file.

Answer 2

[Steven Lord]

Call fopen with two outputs. If the first output is -1, display the second output to see why the file open operation did not succeed.