Today, I’ll talk about how to create a “diary” of the commands launched on the terminal. We all know that with the history command we can see recently launched commands, and that there is also a file (.bash_history or .zsh_history, depending on which shell you are using); but, often you only want to have a portion of the history.
More precisely, we want to create what in other languages and on other platforms is called diary: to be more specific, “ok, from here on record the commands I write and save in another file”. It is often used to keep track of a job, an analysis, or to keep the work done in a day, etc.
This, at the moment, cannot be done with the terminal. For this reason, I decided to create a couple of functions that allow us to do this: diarystart and diaryend.
Let’s see how they work.

Diarystart

This function must be launched when you want to start recording subsequent commands.
Its form is very simple: diarystart filename. The filename is the name of the file in which the commands will be saved (it can also contain a path) and must always be specified.
By now, the file is not created yet.

There are 2 things to take into account:

At this point, you are free to execute the commands of interest and work on the terminal.

Diaryend

Once you are done working and want to save the history of the commands after diarystart, you run the diaryend command by itself. This function will create a file (the one specified in diarystart) in which there will be a list of the commands used.
A peculiarity of this pair of functions is that if you forget to launch diaryend at the end of the day, you can easily launch it at the beginning of the next day.

Example

Below is a small example of how these functions work:

How can they come in handy?

Here are some uses that came to my mind when I decided to create these functions:

You can download these functions from my github.