I have a habit of spamming commands when I get impatient. Like this:

 374  ssh -v preetam@10.10.13.139
 375  ssh -v preetam@10.10.13.139
 376  ssh -v preetam@10.10.13.139
 377  ssh -v preetam@10.10.13.139
 378  ssh -v preetam@10.10.13.139
...
 402  ssh -v preetam@10.10.13.139
 403  ssh -v preetam@10.10.13.139
 404  ssh -v preetam@10.10.13.139
 405  ssh -v preetam@10.10.13.139

By default, Bash on macOS doesn’t remove duplicates, so I have to skip through them when I use the ↑ key to go back through my history.

Fortunately, I can add one line to my ~/.profile to remove those duplicates.

export HISTCONTROL=ignoredups