weird issue with fgetl

Hello,

I have a text document called 'num.dat' that contains:

969592914

969592915

969592916

969592917

when I execute the commands:

fid = fopen('num.dat','rt');

fgetl(fid)

fgetl(fid)

I get the output:

ans = 
'969592914'

ans =
''

Instead of (as I expected):

ans = 
'969592914'

ans =
'969592915'

And I can't figure out why, thanks in advance!

Answer 1

[KSSV]

That is not weird. You should know that the second line is empty so the output is ''. To get your expected behavior remove the blank spaces. Or alternatively you may try:

clc; clear all ;
fid = fopen('num.dat','rt');
l1 = fgetl(fid)
while ~isa(l1,'double')
    l1 = fgetl(fid)  
end
fclose(fid) ;

Answer 2

[Walter Roberson]

You posted here with a format that suggests there are blank lines in the input. If so then the second fgetl() is going to retrieve the blank line after the first line. fgetl() does not skip empty lines.

If this does not seem to be the issue, please attach a copy of a file that it happens for.