New version of zsh still shows old value for $SHELL variable

Introduction

In this article, we will explore the recent upgrade of the Z shell (zsh) from version 5.7.1 to 5.9 and how it may affect users who have both the old and new versions installed on their system. We will cover key concepts related to the zsh, including its configuration, startup files, and the differences between the two versions.

Background

The Z shell, also known as zsh, is a popular command-line interpreter for Unix-like operating systems. It is an extended version of the Bourne shell (sh) and provides several enhancements, including a more powerful and customizable command-line interface, improved tab completion, and advanced scripting capabilities.

With the recent upgrade to version 5.9, users may notice changes in the login shell general properties dialog and other areas of the zsh. In particular, there are now two zsh executables on the system: the old one located at /bin/zsh and the new one at /usr/local/bin/zsh.

Configuration and Startup Files

When a user logs in or starts a new terminal session, the zsh reads several configuration and startup files to set up the environment. These files include:

• ~/.zshenv: This file is sourced (i.e., executed) for all login and non-login shells. It is typically used to set environment variables and other system-wide settings.
• ~/.zprofile: This file is sourced for login shells only. It is typically used to set up the user's environment, such as setting the PATH variable and configuring the terminal.
• ~/.zshrc: This file is sourced for interactive shells only. It is typically used to configure the command-line interface, such as setting up tab completion and customizing the prompt.

It is important to note that any changes made to these files will affect both the old and new versions of the zsh. Therefore, users should be careful when modifying these files to avoid unexpected behavior.

Differences Between Version 5.7.1 and 5.9

The following are some of the key differences between version 5.7.1 and 5.9 of the zsh:

• The login shell general properties dialog has been changed in version 5.9. This dialog allows users to configure various aspects of their login shell, such as the default shell, the terminal type, and the history settings.
• Several new options and features have been added to version 5.9, such as the ability to disable the history file, improved support for Unicode and emoji, and enhanced tab completion for several popular command-line tools.
• Bug fixes and performance improvements have been made in version 5.9, resulting in a more stable and faster shell.

Code Blocks

Here is an example of how to configure the tab completion for the git command in the ~/.zshrc file:

This code block uses the autoload and compinit functions to enable tab completion for the git command. The zstyle function is then used to customize the tab completion behavior for git, specifying the order in which different types of completions are displayed.

Summary and References

In this article, we have explored the recent upgrade of the Z shell from version 5.7.1 to 5.9 and how it may affect users who have both the old and new versions installed on their system. We have covered the key concepts related to the zsh, including its configuration, startup files, and the differences between the two versions.

• The official Z shell website
• The zsh manual page on Linux.die.net
• The Z shell User’s Guide