MATLAB: How to delete a specific line from a text file

fgetstext file

Hi there guys,
I have a list of file locations that I have saved in a .txt file, all on new lines, like so:
C:\\User\Documents\file_name
C:\\User\Documents\file_name_2
C:\\User\Documents\file_name_3
C:\\User\Documents\file_name_4
I want to look through the file and see if the name in my .txt matches a predetermined name that I have previously chosen, and then delete it.
I can go through and find the one I want to delete with this code:
fileID = fopen('file_names.txt','wt');
num = length(importdata('Possiblelocs.txt');
            for ii = 1:num
                check = fgets(fileID(ii));
                if check == new_str
                    'You found it!'
                     break;
                else
                    continue;
                end
            end
However, I don't think this is a particularly good way of finding it, nor do I know how to delete the entire line when I have. Could anyone point me in the right direction? Thank you!

Best Answer

It's a sequential file so there isn't any way trivially to do what you want to the file itself. The right way would be to read the file, find the row in memory, delete it still in memory, then rewrite the file.
fileData=textread('file_names.txt','%s','delimiter','\n','whitespace','');
ix=~cellfun(@isempty,strfind(fileData,newstr));
fileData(ix)=[];
fid=fopen('file_names.txt','w');
for i=1:length(fileData)
  fprintf(fid,'%s\n',fileData{i});
end
fid=fclose(fid);
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