command history with updates

How do I import my command history from a previous release, once I have installed a new one ?

[Allen]

Roy,

Can you provide additional information regarding what steps you took to install the new version. For example:

• Did you uninstall the older version prior to installing the new version?
• If you still have both versions on your computer, if you open the older version, is the command history retained there?

[Roy Torbert]

I have both versions. The old version (2017b) still has command history.

[Roy Torbert]

Is there an answer to my question ?

[Fangjun Jiang]

I suggested below. Did you try?

Answer 1

[Fangjun Jiang]

The command history is saved as history.xml for different versions. See if you can simply copy over the file.

C:\Users\XYZ\AppData\Roaming\MathWorks\MATLAB\R2019b\History.xml

C:\Users\XYZ\AppData\Roaming\MathWorks\MATLAB\R2018b\History.xml

[Roy Torbert]

This applies to windows machines, and i am Mac. However, I found out how to do it and am now fine.

[Fangjun Jiang]

How did you do it? Please provide an answer. It might help others.

[Roy Torbert]

On a Mac, I went to /Users/XYZ/Library/Pallication Support/Mathworks/Matlab/R2017a ( old version)

and copied the history.xml file to the same sort of directory but ending with R2019b ( new version).

Thanks

[Walter Roberson]

Pallication Support

I think you mean Application Support

[Fangjun Jiang]

Wow, took more than 5 years to discover a typo! What are you doing? I am curious.

Answer 2

[Matt Stead]

I wote this function, which works, but the history is not updated until Mtalb is relaunched. So this is part answer and part question. If anyone knows how to get Matalb to reload the history file without relaunching, I would love to know. Here is my function:

function append_history(cmd, exec_time)
    % exec_time is in microseconds
    % tic; <command>; exec_time = round(toc * 1e6);

    hist_path = fullfile(prefdir,'History.xml');
    if (exist(hist_path,'file'))
        % read history file
        txt = fileread(hist_path);

        % condition cmd
        if (isstring(cmd))
            cmd = char(cmd);
        end
        len = length(cmd);
        if (cmd(len) ~= ';')
            cmd(len + 1) = ';';
        end

        % build xml history entry
        xml_cmd = ['<command execution_time=' '"' num2str(exec_time) '">' cmd '</command>' newline];
        new_txt = insertBefore(txt, '</session>', xml_cmd);

        % write out file
        fp = fopen(hist_path, 'w');
        fwrite(fp, new_txt, 'char');
        fclose(fp);
    else
        beep
        fprintf(2, 'File not found: ''History.xml''\n');
        disp('Cannot update history.');
        return
    end
end