I have multiple data files that, sometimes, I want to delete unnecessary extra data lines in them, say from line 8000 to the last line. I want to do that for all the data files, which are contained in .txt files. I used to do it manually, but it's a tedious job to do that frequently. I have combined and modified some codes that found I online, but I have two issues with it:
- I don't know how to set the range, so that the code will delete all lines after line 8000. until the end of data Therefore I have assumed that the number of lines to be deletes is some large number (1000). But that's not a good solution, since the total number of lines in the data file might be more than 9000.
- The second thing is that I cannot copy or move the created temp file, which contains the new data without the extra lines to replace the original file :( I found out the the universally unique identifier (UUID) in the temp folder is not the same as the one in the "
outfile" for instance the UUID code foroutfilein Matlab istp58460076_aaad_4621_b2ac_c7036febc3f0and in temp folder it istp30ade3f8_3abc_4e00_a2ef_26d67c5f836eI have used bothcopyfileandmovefilein Matlab
If someone have an alternative solution or knows what's going wrong with this code, please help!
close all
clear
clc
% Specify the folder where the files live.
myFolder = 'C:\Users\Emma\Data';
% Check to make sure that folder actually exists. Warn user if it doesn't.
if ~isdir(myFolder)
errorMessage = sprintf('Error: The following folder does not exist:\n%s', myFolder);
uiwait(warndlg(errorMessage));
return;
end
% Get a list of all files in the folder with the desired file name pattern.
filePattern = fullfile(myFolder, '*.txt'); % Change to whatever pattern you need.
theFiles = dir(filePattern);
for k = 1 : length(theFiles)
baseFileName = theFiles(k).name;
fullFileName = fullfile(myFolder, baseFileName);
fprintf(1, 'Now reading %s\n', fullFileName);
%*****************************
first_line_to_delete = 8003;
num_lines_to_delete = 1000;
infilename = fullFileName;
[pathstr, file, ext] = fileparts(infilename);
backfile = fullfile(pathstr, [file '.bak']);
if strcmp(infilename, backfile)
error('I refuse to edit a backup file! Nothing has been changed.');
end
outfile = tempname; %a temporary file in TMP directory
fin = fopen(infilename, 'r');
if fin < 0; error('Input file does not exist'); end
fout = fopen(tempname, 'w');
if fout < 0
fclose(fin);
error('Could not open temporary output file');
end
%read lines before the one to be deleted and write them to output
for K = 1 : first_line_to_delete - 1;
inline = fgets(fin);
if ~ischar(inline); break; end; %end of file?
fwrite(fout, inline);
end
for K = 1 : num_lines_to_delete;
if ~ischar(inline); break; end %in case EOF
inline = fgets(fin); %and do nothing with it
end
%copy all remaining input lines to output file
while ischar(inline)
inline = fgets(fin);
if ischar(inline) %not if we hit EOF
fwrite(fout, inline);
end
end
fclose(fin);
fclose(fout);
%we did the copying and have a file with the desired
%result. Now put it in the proper place
[status,message,messageId] = copyfile(infilename, backfile, 'f'); %Emma mod
if ~status
if strcmp(infilename, backfile)
fprintf(2, 'Good thing your programmer is paranoid about people overriding\nsanity checks, because something went wrong and you nearly lost your file!\n');
else
delete(backfile);
end
error('Could not rename file to .bak, file left untouched');
else
[status,message,messageId] = copyfile(fullfile(outfile, [myFolder, infilename]), 'f');
if ~status
error( ['Could not rename temp file to original name, original moved to ', backfile]);
end
end
%**************************
end
