how to compare two files line by line?

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I want to compare two files line by line and count how many lines they have in common , I tried the code below , but it doesn't work , somehow MATLAB stops working , ">>" just disappear
f = fopen('nv.txt','at');
fid = fopen('test.txt');
k = 0;
while ~feof(fid)
s1 = fgetl(fid);
if ~isempty(s1)
while ~feof(f)
s2 = fgetl(f);
if ~isempty(s2)
if(strcmp(s1,s2))
k = k+1;
end
end
end
end
end
fclose(fid);
fclose(f);
disp(k);
  1 Comment
Image Analyst
Image Analyst on 12 Mar 2016
If the second line is missing in one of the files, (and the rest of the lines are just moved up one) then do you say that from line 2 on they are all different?
What if the lines are all there but in some different order?

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Accepted Answer

MHN
MHN on 12 Mar 2016
Edited: MHN on 12 Mar 2016
f = fopen('nv.txt');
fid = fopen('test.txt');
k = 0;
while ~feof(fid)
s1 = fgetl(fid);
frewind(f) % start from the first line of the second file
if ~isempty(s1)
while ~feof(f)
s2 = fgetl(f);
if ~isempty(s2)
if(strcmp(s1,s2))
k = k+1;
end
end
end
end
end
fclose(fid);
fclose(f);
disp(k);
  3 Comments
MHN
MHN on 12 Mar 2016
Please use the "accepted answer" button. Are you sure? I run the program line by line and it compares every lines include the first one.
Zineb EL MORCHID
Zineb EL MORCHID on 12 Mar 2016
Yes Thank you, it works , I find out that one of the lines starts with space.

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More Answers (2)

Image Analyst
Image Analyst on 12 Mar 2016
Did you try the Compare tool on the Editor tool strip?
  2 Comments
Zineb EL MORCHID
Zineb EL MORCHID on 12 Mar 2016
Not really,I actually want the code to use it as a function in my program. Thank you
Adam Danz
Adam Danz on 20 Nov 2021
This is best approach.
Also see visdiff.

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r r
r r on 11 May 2021
I have two files with similar data and I want to extract them into a file, and I also want to print the same line for the same data in the two files
Please help me
F1 = fopen('E.txt');
T1 = textscan(F1,'%s', 'delimiter', '\n');
fclose(F1);
F2 = fopen('G.txt');
tt2 = textscan(F2,'%s', 'delimiter', '\n');
fclose(F2);
T1s = char(T1{:});
T2s = char(T2{:});
[C,ix,ic] = intersect(T1s,T2s,'rows')
%%%%%%%%%%%%%%%%%%out Fiel :::
dlmwrite('R.txt',C,'%.6f');

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