Bibliography sorting (Matlab Code)

Those who write papers, especially longer one, they know how difficult and irritating it is to sort the bibliography every time you change the text. I made this little code to sort the bibliography as they appear in the text using '\cite{}'. Some journal does not allow to sort the bibliography as it appear in the figure caption. I have not given any special care to it for simplicity. The code appears below in a very misaligned fashion. It should work pretty well.

function bibsort(fname,bibfile,outfile)
%
% 'bibsort' sorts the bibliography of the main latex file
% as the references appear in the text.
%
% bibsort('paper.tex','bibliography.tex',''outputfile.tex')
% will find the citation from file 'paper.tex' and find the
% bibliography from file 'bibliography.tex' and the sorted bibliograpy
% will be written in 'outputfile.tex'. Default biblography file is the
% main file and the default outputfile is 'bib.tex'.
%
% This program will identify a reference as written in '\cite{reference}'
% in the main file and then search for that reference in the bibliograpy
% as written in '\bibitem{refererence}'. More reference as seperated
% by , inside one '\cite{}' is incorporated. Again, one '\cite{}' as
% splitted into two lines are also taken care of.
%
% Tanmoy Das.
% Feb 12 2008.
%
if nargin<1;error('Specify your input latex file');end;
if nargin ==1;bibfile=fname;outfile = 'bib.tex';end;
if nargin ==2;outfile = 'bib.tex';end;
%
fid = fopen(fname,'rt');
if fid<0;error(sprintf('%s%s%s','Input file [',fname,'] NOT found'));end
bfid = fopen(bibfile,'rt');
if bfid<0;error(sprintf('%s%s%s','Bibliography file [',bibname,'] NOT found'));end
ofid = fopen(outfile,'w');
%
% Identify all the references and save in variable 'd'
b = 'cite{';
ii = 1; % No of references as identified
while feof(fid) == 0;
tline = fgetl(fid); %read one line
len = length(tline);
if len>=1&tline(1)=='%';continue;end
% find the indices where refereces are located
indi = findstr(tline, b);
%num = length(indi);
if length(indi) > 0
len1= length(indi);
ik = 1; % index for the length of a reference
ij = 1; % index for the no of reference in one line
while (ij<=len1)
%tline(indi(ij)-1)
if (indi(ij)>2)&(tline(indi(ij)-2)=='%');ij=ij+1;continue;end;
il = indi(ij)+5;
while(il<=len)
c = tline(il); % store one character of the line
%} is found then the ref(s) in \cite{} is identified
if c=='}' ;ii= ii+1; ik=1; break; end;
% if , in \cite{} is found then one ref if identified
if c==','; ik=1; ii=ii+1; il = il+1; end;
d(ii,ik)=tline(il); % Store one character of a ref.
ik = ik+1; % increases the character length of a ref
% check if the line is finished before identifying one full
% ref.
if il==len;
tlinen = fgetl(fid); % go to net line
while length(tlinen)>=1&tlinen(1)=='%';
tlinen = fgetl(fid); % go to net line
end
tline = [tline tlinen]; % add the new line to old one
len = length(tline); % modify the new line length
% look for aditional '\cite{' in the new line
indi = findstr(tline, b);
% modify the new no of '\cite{' in the total line
len1=length(indi);
end
il = il+1; % go to the next character in the line
end %while: all ref found under one '\cite'
ij = ij+1; % go to the next '\cite'
end %while
end % if
end % while
%%%%%%%%%%%%%%%%%%%%%
% Now remove the same reference and store all independent references in
% 'f', as they are in order
%%%%%%%%%%%%%%%%%%%%%
ii = 1;
f(ii,:) = d(ii,:);
for ij = 2:size(d,1)
flag = 0;
for ik = ij-1:-1:1
if d(ij,:)==d(ik,:);flag = 1;break;end;
end
if (flag==0)
ii = ii+1;
f(ii,:) = d(ij,:);
else
continue
end
end
fclose(fid);
%
% Now look for the references fron 'The bibliograpy'
%
bfid = fopen(bibfile,'rt');
while feof(bfid) == 0;
tline = fgetl(bfid);
%if length(tline)>=1&tline(1)=='%';continue;end
indi = findstr(tline, sprintf('%s%s%s','\begin{thebibliography'));
num = length(indi);
if num > 0
fprintf(ofid,'%s\n',tline);
break;
end
end
fclose(bfid);
%
for ii = 1:size(f,1)
bfid = fopen(bibfile,'rt');
while feof(bfid) == 0;
tline = fgetl(bfid);
%if length(tline)>=1&tline(1)=='%';continue;end
indi = findstr(tline, sprintf('%s%s%s','\bibitem{',f(ii,:),'}'));
num = length(indi);
if num > 0
if (indi(1)>1)&(tline(indi(1)-1)=='%');continue;end;
fprintf(ofid,'%s\n',tline);
num2 = 0;
while (num2==0)
tline1 = fgetl(bfid);
%while length(tline1)>=1;%&tline1(1)=='%';
% tline1 = fgetl(fid);
%end
ind1 = findstr(tline1, '\end{thebibliography');
num1 = length(ind1);
if num1 >0;break;end;
ind2 = findstr(tline1, '\bibitem{');
num2 = length(ind2);
if num2==0;
%tline = [tline; tline1];
fprintf(ofid,'%s\n',tline1);
end;
end
% fprintf(ofid,'%s\n',tline);
break
end
end
fclose(bfid);
if(num<=0)error(sprintf('%s%s%s','Reference[',f(ii,:),']not found'));end;
end
%
bfid = fopen(bibfile,'rt');
while feof(bfid) == 0;
tline = fgetl(bfid);
%if length(tline)>=1&tline(1)=='%';continue;end
indi = findstr(tline, sprintf('%s%s%s','\end{thebibliography'));
num = length(indi);
if num > 0
fprintf(ofid,'%s\n',tline);
end
end
fclose(bfid);
fclose(ofid);

return