Why `which tmux` and `sudo which tmux` return 2 different values?

Question

ssh bobby@tony:~$ which tmux                                                                        
/usr/bin/tmux
ssh bobby@tony:~$ sudo which tmux                                                                   
/usr/local/bin/tmux
ssh bobby@tony:~$ echo $PATH                                                                        
/usr/bin:/bin:/usr/sbin:/sbin:/usr/local/bin:/usr/X11/bin:/usr/local/git/bin:/usr/local/sbin:/usr/local/sbin
ssh bobby@tony:~$ sudo echo $PATH                                                                   
/usr/bin:/bin:/usr/sbin:/sbin:/usr/local/bin:/usr/X11/bin:/usr/local/git/bin:/usr/local/sbin:/usr/local/sbin

Anyone knows what's going on here? Why does sudo which tmux return /usr/local/bin/tmux instead of /usr/bin/tmux?

PS: I have 2 versions of tmux installed (one in /usr/bin and the other in /usr/local/bin).

Answer 1

It's because your root user has a different path.

sudo echo $PATH

prints your path. It's your shell that does the variable expansion, before sudo starts (and passes it as a command line argument, expanded).

Try:

sudo sh -c 'echo $PATH'