Separate chars of a file in matlab - string

Question

I have strings of 32 chars in a file (multiple lines).
What I want to do is to make a new file and put them there by making columns of 4 chars each.
For example I have:
00000000000FDAD000DFD00ASD00
00000000000FDAD000DFD00ASD00
00000000000FDAD000DFD00ASD00
....
and in the new file, I want them to appear like this:
0000 0000 000F DAD0 00DF D00A SD00
0000 0000 000F DAD0 00DF D00A SD00
Can you anybody help me? I am working for hours now and I can't find the solution.

Answer 1

First, open the input file and read the lines as strings:
infid = fopen(infilename, 'r');
C = textscan(infid, '%s', 'delimiter', '');
fclose(infid);
Then use regexprep to split the string into space-delimited groups of 4 characters:
C = regexprep(C{:}, '(.{4})(?!$)', '$1 ');
Lastly, write the modified lines to the output file:
outfid = fopen(outfilename, 'w');
fprintf(outfid, '%s\n', C{:});
fclose(outfid);
Note that this solution is robust enough to work on lines of variable length.

Answer 2

Import
fid = fopen('test.txt');
txt = textscan(fid,'%s');
fclose(fid);
Transform into a M by 28 char array, transpose and reshape to have a 4 char block on each column. Then add to the bottom a row of blanks and reshape back. Store each line in a cell.
txt = reshape(char(txt{:})',4,[]);
txt = cellstr(reshape([txt; repmat(' ',1,size(txt,2))],35,[])')
Write each cell/line to new file
fid = fopen('test2.txt','w');
fprintf(fid,'%s\r\n',txt{:});
fclose(fid);

Answer 3

Here's one way to do it in Matlab:
% read in file
fid = fopen('data10.txt');
data = textscan(fid,'%s');
fclose(fid);
% save new file
s = size(data{1});
newFid = fopen('newFile.txt','wt');
for t = 1:s(1) % format and save each row
line = data{1}{t};
newLine = '';
index = 1;
for k = 1:7 % seven sets of 4 characters
count = 0;
while count < 4
newLine(end + 1) = line(index);
index = index + 1;
count = count + 1;
end
newLine(end + 1) = ' ';
end
fprintf(newFid, '%s\n', newLine);
end
fclose(newFid);