To write data to the top of the file, it is better to create a new file and write the required data to it.
- Create a new file.
- Write the new data to the file.
- Read the old file and keep appending the data to the new file.
inputFile = fopen('currentFile.txt','r');
outputFile = fopen('newFile.txt','w+');
% create sample data to write to the new file
data = [ [1:10] ; [21:30] ];
fprintf(outputFile, '%5.3f %5.3f \n',data);
while true
line = fgetl(inputFile);
if ~ischar(line)
break;
end
fprintf(outputFile,'%s \n',line);
end
fclose(inputFile);
fclose(outputFile);
