Linux

It only works with the first command in the recorded history, not with any sub shells or chained commands.

#!/usr/bin/env bash

# 1. history and $HISTFILE do not work in scripts. Therefore cat with a direct
#    path is needed.
# 2. awk gets the first part of the command name.
# 3. List is then sorted and duplicate entries are removed.
# 4. type -P will expand command names to paths, similar to which. But it will
#    also expand aliases and functions.
# 5. Final output is then sorted again.

type -P $(cat ~/.bash_history | awk '{print $1}' | sort | uniq) | sort

After reading a blog post, I had this script in mind to see if its possible. This is just for fun and I don't have an actual use for it. Maybe some parts of it might inspire you to do something too. So have fun.

Edit 1:

After some suggestions from the comments, here is a little shorter version. sort | uniq can be replaced by sort -u, as the output of them should be identical in this case (in certain circumstances they can have different effect!). Also someone pointed out my useless cat, as the file can be used directly with awk. And for good reason. :D Enjoy, and thanks for all.

type -P $(awk '{print $1}' ~/.bash_history | sort -u) | sort

I still have no real use case for this one liner, its mainly just for fun.