No matter which shell you use in a terminal, the prompt probably looks very dull in the vast majority of cases and only provides basic information – typically just telling you the current working directory. Fortunately, the vast majority of shells offer users a function for customizing the prompt. Prompt engines such as Powerline or Oh My Zsh take advantage of this. As a rule, they use various themes that give the environment a more appealing look.

These engines can also display useful information in the input line. The is then typically broken down into different segments, which gives you the opportunity to populate these segments with the kind of information you actually need. In the simplest case, you might display the date or time in one segment. More complex configurations let you embed almost any kind of data. For example, in Git directories, you could use a segment to display the kind of information that you need for Git, such as the status of the current repository.

Theme Engines and Nerd Fonts

Powerline [1] provides a very powerful engine and not only for customizing the shell prompt. Instead, the software can customize a variety of different status lines, also in the Vim editor. Oh My Zsh [2] is a popular configuration tool for the Zsh. Similar to Oh My Zsh, Oh My Posh [3] lets you customize the shell prompt. Unlike Oh My Zsh, however, it doesn't matter which shell you actually use in your environment.

Like with most other prompt engines, it makes sense to use Nerd Fonts [4] in combination with Oh My Posh. Nerd Fonts extends the regular character set to include a variety of icons that you can then use within each shell segment. Oh My Posh recommends the use of Meslo LGM [5], but you can use any other font as long as it comes with a good supply of icons. You can install the desired font manually or via Oh My Posh – but more about that later.

Cross-Platform Support

Oh My Posh is a cross-platform tool; you can use it on Linux, macOS, and in PowerShell on Windows. On macOS, simply install the engine using the Homebrew package manager:

brew install jandedobbeleer/oh-my-posh/oh-my-posh

The call installs both the Oh My Posh tool and the available themes (Figure 1). On Linux, first download the software and then an archive with all the themes, which you then unpack (Listing 1).

Figure 1: Even with the default theme, Oh My Posh already gives you an appealing prompt.

Activating the Shell Prompt

Now, to enable Oh My Posh in the shell you are using, initialize the prompt engine in the shell's configuration file. For example, if you use Bash, add the following line to the ~/.bashrc file:

eval "$(oh-my-posh init bash)"

To activate the changes, either start a new shell or reload the modified configuration file with the source ~/.bashrc command. The procedure is similar if you use Zsh. Of course, in this case you need to pass in Zsh as the init argument. A complete overview showing you the configurations of all the shells supported by Oh My Posh is available in the documentation [6].

You can also call up the Oh My Posh tool interactively to define a whole bunch of configuration settings. For example, if you want to install a Nerd Font on your system, simply run:

oh-my-posh font install

In the drop-down menu, select the font you want to download. However, you will need to handle the configuration manually in the terminal you are using later.