Uses zsh only if zsh is installed

[hunterclarke]

Currently, the install script creates a .zshrc file, then uses the presence of that file as the indication that the system uses zsh. Instead, test that zsh is installed before taking steps to use zsh.

Why

The install script is broken if zsh is not installed.

What is changing

Check for zsh before configuring zsh in the install script.

How to test

1. Run install.sh in master on a machine that doesn't have zsh installed. Install should fail with /bin/bash: line 72: zsh: command not found
2. Run the updated install.sh on a machine that doesn't have zsh installed. Install should succeed and the running shell should remain in place.
3. Install zsh and run the updated install.sh. Install should succeed and the running shell should switch to zsh.

[aquib-sh]

Hi, I think you are still creating the .bashrc again and then again checking if .bashrc exists and then adding PATH into it. I think this part is not needed if the person is using zsh. I think maybe you should modify it to first check whether the user has zsh or bash and then add code to update only those configuration files.

if [ ! -f "$HOME/.bashrc" ]; then
	touch "$HOME/.bashrc"
fi

if [ -x "$(command -v zsh)" ] && [ ! -f "$HOME/.zshrc" ]; then
	touch "$HOME/.zshrc"
fi

if [ -x "$(command -v zsh)" ]; then
	echo "" >> "$HOME/.zshrc"
	echo "export PATH=\"$BINARY_PATH:\$PATH\"" >> "$HOME/.zshrc"
fi
if [ -f "$HOME/.bashrc" ]; then
	echo "" >> "$HOME/.bashrc"
	echo "export PATH=\"$BINARY_PATH:\$PATH\"" >> "$HOME/.bashrc"
fi