Add new line in middle of line of a text file

I have a bug in my text file. There should be new line at this blue line:

I have tried to code to fix this:

subdir = 'TCLFiles';
filename = 'Sections.tcl';
str = deblank(fileread(fullfile(pwd,subdir,filename)));
[oldhash,nonhash] = regexp(str,'\#','match','split');
nonhash = nonhash(2:end);
newtext = cell(1,length(oldhash));
for i=1:length(oldhash)
    newtext{i} = sprintf('\n%s%s',oldhash{i},nonhash{i});
end
fid = fopen(fullfile(pwd,subdir,'Sections_fixed.tcl'),'wt');
fprintf(fid,'%s',newtext{:});
fclose(fid);

It works, but it creates many other unnecessary new lines. The result is quite a mess:

Its hard to understand these working-with-text. Any suggestion how to do it properly?

I attach the text file also if you need to take a look. Thank you.

Answer 1

[Voss]

unzip('Sections.zip')

% subdir = 'TCLFiles';
subdir = '';
oldfilename = fullfile(pwd,subdir,'Sections.tcl');
newfilename = fullfile(pwd,subdir,'Sections_fixed.tcl');

% original file contents, for reference
type(oldfilename)

# Sections.tcl 

# Section "ElasticDefault":    secTag    E    A    Iz    Iy    G    J    <alphaY>    <alphaZ> 
section  Elastic      20  +2.900000E+04  +1.800000E+02  +4.860000E+03  +1.500000E+03  +1.115400E+04  +3.916000E+03  +8.333333E-01  +8.333333E-01 

# Section "A01Sect":    secTag    matTag    string ...    -section secTag 
section  Aggregator       1  1 P  21 My  21 Mz  # Section "A02Sect":    secTag    matTag    string ...    -section secTag 
section  Aggregator       2  2 P  21 My  21 Mz  # Section "A03Sect":    secTag    matTag    string ...    -section secTag 
section  Aggregator       3  3 P  21 My  21 Mz  # Section "A04Sect":    secTag    matTag    string ...    -section secTag 
section  Aggregator       4  4 P  21 My  21 Mz  # Section "A05Sect":    secTag    matTag    string ...    -section secTag 
section  Aggregator       5  5 P  21 My  21 Mz  # Section "A06Sect":    secTag    matTag    string ...    -section secTag 
section  Aggregator       6  6 P  21 My  21 Mz  # Section "A07Sect":    secTag    matTag    string ...    -section secTag 
section  Aggregator       7  7 P  21 My  21 Mz  # Section "A08Sect":    secTag    matTag    string ...    -section secTag 
section  Aggregator       8  8 P  21 My  21 Mz  # Section "A09Sect":    secTag    matTag    string ...    -section secTag 
section  Aggregator       9  9 P  21 My  21 Mz  # Section "A10Sect":    secTag    matTag    string ...    -section secTag 
section  Aggregator      10  10 P  21 My  21 Mz  # Section "A11Sect":    secTag    matTag    string ...    -section secTag 
section  Aggregator      11  11 P  21 My  21 Mz  # Section "A12Sect":    secTag    matTag    string ...    -section secTag 
section  Aggregator      12  12 P  21 My  21 Mz  # Section "A13Sect":    secTag    matTag    string ...    -section secTag 
section  Aggregator      13  13 P  21 My  21 Mz  # Section "A14Sect":    secTag    matTag    string ...    -section secTag 
section  Aggregator      14  14 P  21 My  21 Mz  # Section "A15Sect":    secTag    matTag    string ...    -section secTag 
section  Aggregator      15  15 P  21 My  21 Mz  # Section "A16Sect":    secTag    matTag    string ...    -section secTag 
section  Aggregator      16  16 P  21 My  21 Mz  # Section "A17Sect":    secTag    matTag    string ...    -section secTag 
section  Aggregator      17  17 P  21 My  21 Mz  # Section "A18Sect":    secTag    matTag    string ...    -section secTag 
section  Aggregator      18  18 P  21 My  21 Mz  # Section "A19Sect":    secTag    matTag    string ...    -section secTag 
section  Aggregator      19  19 P  21 My  21 Mz  

% read the original file
str = fileread(oldfilename);

% replace any "#" that is not directly preceded by a newline character
% with a newline followed by a "#". that is, prepend a newline to any #
% that doesn't already have one
str = regexprep(str,'[^\n]#','\n#');

% write the new file
fid = fopen(newfilename,'wt');
fprintf(fid,'%s',str);
fclose(fid);

% check the new file contents (scroll down to see the whole thing)
type(newfilename)

# Sections.tcl 

# Section "ElasticDefault":    secTag    E    A    Iz    Iy    G    J    <alphaY>    <alphaZ> 
section  Elastic      20  +2.900000E+04  +1.800000E+02  +4.860000E+03  +1.500000E+03  +1.115400E+04  +3.916000E+03  +8.333333E-01  +8.333333E-01 

# Section "A01Sect":    secTag    matTag    string ...    -section secTag 
section  Aggregator       1  1 P  21 My  21 Mz 
# Section "A02Sect":    secTag    matTag    string ...    -section secTag 
section  Aggregator       2  2 P  21 My  21 Mz 
# Section "A03Sect":    secTag    matTag    string ...    -section secTag 
section  Aggregator       3  3 P  21 My  21 Mz 
# Section "A04Sect":    secTag    matTag    string ...    -section secTag 
section  Aggregator       4  4 P  21 My  21 Mz 
# Section "A05Sect":    secTag    matTag    string ...    -section secTag 
section  Aggregator       5  5 P  21 My  21 Mz 
# Section "A06Sect":    secTag    matTag    string ...    -section secTag 
section  Aggregator       6  6 P  21 My  21 Mz 
# Section "A07Sect":    secTag    matTag    string ...    -section secTag 
section  Aggregator       7  7 P  21 My  21 Mz 
# Section "A08Sect":    secTag    matTag    string ...    -section secTag 
section  Aggregator       8  8 P  21 My  21 Mz 
# Section "A09Sect":    secTag    matTag    string ...    -section secTag 
section  Aggregator       9  9 P  21 My  21 Mz 
# Section "A10Sect":    secTag    matTag    string ...    -section secTag 
section  Aggregator      10  10 P  21 My  21 Mz 
# Section "A11Sect":    secTag    matTag    string ...    -section secTag 
section  Aggregator      11  11 P  21 My  21 Mz 
# Section "A12Sect":    secTag    matTag    string ...    -section secTag 
section  Aggregator      12  12 P  21 My  21 Mz 
# Section "A13Sect":    secTag    matTag    string ...    -section secTag 
section  Aggregator      13  13 P  21 My  21 Mz 
# Section "A14Sect":    secTag    matTag    string ...    -section secTag 
section  Aggregator      14  14 P  21 My  21 Mz 
# Section "A15Sect":    secTag    matTag    string ...    -section secTag 
section  Aggregator      15  15 P  21 My  21 Mz 
# Section "A16Sect":    secTag    matTag    string ...    -section secTag 
section  Aggregator      16  16 P  21 My  21 Mz 
# Section "A17Sect":    secTag    matTag    string ...    -section secTag 
section  Aggregator      17  17 P  21 My  21 Mz 
# Section "A18Sect":    secTag    matTag    string ...    -section secTag 
section  Aggregator      18  18 P  21 My  21 Mz 
# Section "A19Sect":    secTag    matTag    string ...    -section secTag 
section  Aggregator      19  19 P  21 My  21 Mz