How can I make "Press any key to continue"

You can use the read command:

read -p "Press enter to continue"

As mentioned in the comments above, this command does actually require the user to press enter; a solution that works with any key would be:

read -n 1 -s -r -p "Press any key to continue"

Explanation by Rayne and wchargin

-n defines the required character count to stop reading

-s hides the user's input

-r causes the string to be interpreted "raw" (without considering backslash escapes)

As @cas wrote in a comment, you really should use less for this. If the changelog is more than one page, you really want a pager anyway.

You normally want to consult the PAGER environment variable instead of just calling less:

${PAGER:-less} changelog

will use $PAGER if it is set and less otherwise.

read -rsn1 -p"Press any key to continue";echo

Or, if you actually need the REPLY variable:

read -rsn1 -p"Press any key to continue" variable;echo

Replace variable with a variable name you don't need.