Really unbelievable that Apple has removed the telnet client in High Sierra. Oh 3825! (read the discussion thread here). It is old, we all know; but to some old folks (like me), it is still a useful debugging tool.

According to the discussion thread, the GNU version seems buggy; but hopefully it is sufficient for me for simple use (or I should learn nc instead 😖).

So, if you insist to try the GNU version, then follow these steps:

  1. Download the tarball (version 1.9.4 is fine) from gnu site: http://ftp.gnu.org/gnu/inetutils/
  2. Untar somewhere else, and run ./configure; make; make install
    • If you prefer to install the files somewhere else (default to /usr/local), then remember to set it with ./configure --prefix=/your/favorite/dir
  3. Either add the bin directory to your PATH, or create a symlink in your ~/bin (assume ~/bin already in your PATH)

For example, I put those files under ~/bin/gnu (which is a symlink to another dir) to avoid problem with existing executables (maybe no problem, but I have no idea). After that, I have created a symlink ~/bin/telnet -> ~/bin/gnu/bin/telnet, and voilà, I am able to use telnet again 😄