How to keep java file formatting after modification in Matlab using fprintf()

I am trying to modify the content of a .java file and write a new modified .java file. Without loss of generality imagine the content is:

 import com

   V8_Final\\Study_components_gap_dependence

and I want the new .java file to be

 import com

   V9_Final\\Study_components_gap_dependence

My approach to do this is as follow:

clc, clear all, close all

%%Import
fid = fopen('A.java','r');
f = textscan(fid,'%s','Delimiter','\n');
txt = f{:};
fclose(fid);

%%Make changes
txt = regexprep(txt,'V8','V9');

%%Write the new file
txt = regexprep(txt,'(.*)','$1\n');
txt = [txt{:}];

fid = fopen('A_mod.java','w');
fprintf(fid,txt);
fclose(fid);

But I get:

import com
V9_Final\Study_components_gap_dependence

I need to keep the blank line in between lines, the spaces before V8... and the double \\, otherwise the .java file is unusable.

All those 3 undesirable changes seems to happen when I do

fprintf(fid,txt);

Any idea how to fix it?

Thank you

Answer 1

[Walter Roberson]

txt = fileread('A.java');

txt = regexprep(txt, 'V8_', 'V9_', 'once');

fid = fopen('A_mod.java', 'w');
fwrite(fid, txt);
fclose(fid);