Write in a file, one ligne before the last one
1 次查看(过去 30 天)
显示 更早的评论
Hi
So i have a function file, and i want to write inside the file. ( sounds weired i know)
but i want toto write one ligne before the last line in the function script.
i made up this eexemole to explaine :
function [out_1, out_2] = test (in_1, )in_2
stuf ... % thethe main code of the function
end
i am using this code toto write inside the function file
file = fopen('test.m','a+')
fprintf(file,'%c','stuf')
fclose(file)
the idea is i want to write before the "end" of the function.
is there a way to Go back 3 caracters or up one ligne to sstart writing?
0 个评论
采纳的回答
Image Analyst
2020-9-1
Yes, open it, read all the lines, counting them in a loop. Then have a second loop reading from the input file, and writing to the output file. When the line number is the count minus 1, call your fprintf() to the output file. Then you can close both files and delete the input file and rename your output file using movefile() if you want. Easy, but let me know if you can't figure it out.
2 个评论
Image Analyst
2020-9-2
Add this robust code:
originalFileName = fullfile(pwd, 'Test.txt');
newFileName = fullfile(pwd, 'Test2.txt');
if isfile(originalFileName) && isfile(newFileName)
recycle('on') % Make sure deleted file goes into recycle bin.
delete(originalFileName); % Delete old one.
movefile(newFileName, originalFileName); % Rename new one.
end
更多回答(1 个)
Mario Malic
2020-9-1
编辑:Mario Malic
2020-9-1
With this, you'll get contents of the file in File_Data which is a cell size (ii,1) with character arrays.
FID = fopen('test.txt', 'r');
ii = 1;
tline = fgetl(FID);
File_Data{ii} = tline;
while ischar(tline)
ii = ii+1;
tline = fgetl(FID);
File_Data{ii} = tline;
end
fclose(FID);
Replacing the second to last line
File_Data{numel(File_Data)-1} = 'Henry the IXth I am';
You can delete the previous file, I am not sure if fopen would overwrite the file if it has the same name.
Write the file with
FID = fopen('test1.txt','wt'); %
for p = 1:numel(File_Data)
if File_Data{p+1} == -1 % -1 denotes the end of file
fprintf(FID,'%s', File_Data{p});
break
else
fprintf(FID,'%s\n', File_Data{p});
end
end
fclose(FID);
4 个评论
Mario Malic
2020-9-1
You changed the order of files
From the documentation:
movefile source destination
%
movefile 'old.txt' 'new.txt'
另请参阅
类别
在 Help Center 和 File Exchange 中查找有关 Data Import and Analysis 的更多信息
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!