function mark_texfiles_latin1
d=dir('*.tex');
dd={d.name};
for i=1:length(dd)
    mark_latin1(dd{i});
end;

function mark_latin1(fname)
enc='% !TeX encoding = latin1';
bname=[fname,'.bak'];
movefile(fname,bname);
disp(fname);
inp=fopen(bname,'r');
out=fopen(fname,'w');
fprintf(out,'%s\n',enc);
line=fgets(inp);
while (line~=-1)
    if ~strncmp(line,enc,24)
        fprintf(out,'%s',line);
    end;
    line=fgets(inp);
end;
fclose(inp);
fclose(out);