manipulating text files

I have a .txt file structured as below:

title

name 00xxxx yyyy

name 00xxxx yyyy

in each line the first n characters describe a name, followed by 67-n spaces, then a 6 digit code starting with 2 zeros and after 9 spaces a 4 digit codes. What i need to do is copy the xxxx numbers to the place of the yyyy numbers in all lines of the file and save it back to .txt file by maintaining the exact structure in the output file. How could i handle something like that in matlab ?

Thanks in advance

Answer 1

[TAB]

fi=fopen('YourFile.txt','r');
fo=fopen('outfile.txt','w');
txtcell=textscan(fi,'%s','delimiter','\n');
Str1Idx=1;
Str2Idx=68;
Str3Idx=82;
StrLen=86;
for i=1:length(txtcell{1})
    if(length(txtcell{1}{i})==StrLen)
        txtcell{1}{i}((Str3Idx):(Str3Idx+4))=txtcell{1}{i}((Str2Idx+2):(Str2Idx+6));
    end
    fprintf(fo,strcat(txtcell{1}{i},'\n'));
end
fclose(fi);
fclose(fo);

[Jan]

You can get txtcell{1} as separate variable. This is much faster and nicer then accessing the data as nested cell.

[conrad Landis]

it works, but i still have a problem concerning the space delimiters after column no 86. My original document has 159 columns in each line and so i want the output file to be exact the same. By removing strcat from your code i am able to print the 159 columns with whitespaces but i can't manage change line to the output.

[TAB]

Try

fprintf(fo,txtcell{1}{i});

fprintf(fo,'\n');

[conrad Landis]

Thanks it works great although it skips a line. Using fgetl does not skip anything:

inputFile = 'input.txt';

outputFile = 'output.txt';

fi=fopen(inputFile,'r');

fo=fopen(outputFile,'w');

jline=0;

while 1

jline = jline+1;

pretxtcell{jline,:} = fgetl(fi);

if ~ischar(pretxtcell{jline}), break, end

if pretxtcell{jline}==-1, break, end

txtcell{jline,:}=pretxtcell{jline};

if jline>=1

txtcell{jline,1}(1,81:86)=pretxtcell{jline,1}(1,67:72);

end

end

fclose(fi);

for i = 1:size(txtcell,1)

fprintf(fo,txtcell{i,1});

fprintf(fo,'\r\n');

end

fclose(fo);

Anyway, thanks a lot