Command "istats" gives "-bash: istats: command not found" after "gem install iStats"

Question

I wanted to use iStats in command line/terminal mode, so I did the following:

• I installed iStats with the command gem install iStats as per this answer to an AskDifferent question;
• However, when I issue the command istats I get a -bash: istats: command not found;
• Issuing the command gem list shows me that iStats is installed (*** LOCAL GEMS *** and in second position it reads iStats (1.6.1);
• I checked and the app resides in /usr/local/lib/ruby/gems/2.6.0/gems/;
• Issuing a gem environment command shows the following - INSTALLATION DIRECTORY: /usr/local/lib/ruby/gems/2.6.0;
• I uninstalled the Gem by issuing gem uninstall iStats;
• Then issuing gem list shows that the app was indeed removed;
• Then I issued gem install iStats that gave the following output: Fetching iStats-1.6.1.gem Building native extensions. This could take a while... Successfully installed iStats-1.6.1 Parsing documentation for iStats-1.6.1 Installing ri documentation for iStats-1.6.1 Done installing documentation for iStats after 0 seconds 1 gem installed
• Issuing istats command gives again -bash: istats: command not found.

Any ideas?

---

System used (just in case):

• macOS Mojave Version 10.14.5
• Ruby version: ruby 2.6.3p62 (2019-04-16 revision 67580) [x86_64-darwin18]
• MacBook Pro (13-inch, 2018, Four Thunderbolt 3 Ports)
• Processor: 2.7 GHz Intel Core i7
• Memory: 16 GB 2133 MHz LPDDR3
• Graphics: Intel Iris Plus Graphics 655 1536 MB

Answer 1

Thanks to historystamp's comment here is how the problem was solved (for bash shell):

1. Open/Launch Terminal
2. gem uninstall iStats (source)
3. gem install iStats --user-install (source)
4. export PATH="~/.gem/ruby/2.6.0/bin:$PATH" (source)
5. source ~/.bash_profile (source)
6. istats

If you use macOS Catalina, the default shell is zsh. The adapted instructions are the following:

1. Open/Launch Terminal
2. gem uninstall iStats (source)
3. gem install iStats --user-install (source)
4. Open or create ~/.zshrc
5. At the end of the file (or where appropriate) insert: export PATH=~/.gem/ruby/2.6.0/bin:$PATH (source)
6. Save file ~/.zshrc
7. Source the .zshrc file: . ~/.zshrc (source)
8. istats