Search and replace a word of text file from GUI

I need to parse a text file in way like what find and replace (strrep) function does in the string. It actually has to get a word (‘new’) as input from the GUI, search within the text file for a special word (‘old’) and replace it.

Any help would be greatly appreciated

Answer 1

[Stephen23]

A text file is a string. So just read the file using fileread, and perform your operations on it:

str = fileread(filename);
str = strrep(str,old,new);

[Saeed Soltani]

Thanks for your quick answer Stephen. And do you have any idea about the GUI part? (Getting the ‘new’ from a user interface)

[Stephen23]

You can use an inputdlg input dialog:

new = inputdlg('Enter the new string:');
str = strrep(str,old,new{1});

[Saeed Soltani]

But how can I connect the handle of user answer to ‚new‘?

Maybe it would be better to write from the basic in GUIDE!

[Stephen23]

It is not clear what "But how can I connect the handle of user answer to ‚new‘?" means. There are no handles involved in the code that I showed you.

I have never used GIUDE, as I find it much easier to actually code my own GUI's.

[Saeed Soltani]

Here is my code. But not only it does not return the enterned value, but also it delete the whole contents of text file.

    % code 
str = fileread('bj.dbc');
prompt = {'Enter the new word that must be replaced'};
Data = 'Replace';
new = inputdlg(prompt,Data);
str = strrep(str,'old',new);
fid = fopen('bj.dbc','w');
fprintf(fid,'%s',str);
fclose(fid);

[Stephen23]

Reading the inputdlg documentation we find that the output is a cell array. strrep also accepts cell arrays of strings, and then returns a cell array. Oops, providing a cell array to fprintf results in this error message:

Error using fprintf
Function is not defined for 'cell' inputs.
Error in bj (line 9)
fprintf(fid,'%s',str);

By the point this error occurs the file has already been opened for writing (and the contents deleted). To solve this we just need to get the string out of the cell array, using cell array indexing:

str = strrep(str,'old',new{1});

[Saeed Soltani]

Thanks a lot Stephen, that was great help :)