MATLAB: Replace specific line in a text file

MATLABtext filetext;textscan

Hi everyone,
I have a text file (for example: data.dat) as shown below, with a number of lines. 
data.dat
@motion parameters
speed= 22,30,60
range= 600
rotation= 50
@controls
act= 2,3,4,5
I want to read it and replace the line that comes right after the line starting with a specfic keyword e.g. "@controls" . In this case, the line to be replaced is this one 
act= 2,3,4,5
and it should be changed in a loop. For an instant, for example, it would change to:
act= 1,0,8,-2
I'd appreciate your help. Thanks in advance.

Best Answer

One of the way could be:
fid = fopen('data.dat','r');        % Open File to read
replaceline = 'act= 1,0,8,-2';      % Line to replace
i = 1;
tline = 's';
A = {[]};
while ischar(tline)
    tline = fgetl(fid);
    if ~isempty(strfind(tline,'@controls')) % find '@controls'
        A{i}=tline;
        A{i+1} = replaceline;               % replace line
        tline = fgetl(fid);
        i = i+1;
    else
        A{i}=tline;
    end
    i = i+1;
end
fclose(fid);
fid2=fopen('data.dat','w');            % Open file to write
for i=1:length(A)-1
    fprintf(fid2,['%s',char([13,10])],A{i});
end
fclose(fid2);
Let me know if you have doubts !
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