How do I prompt for user input using $EDITOR from a script?

Question

I want to have an input mechanism akin to git commit. When the script is run, it should open an editor to edit a temporary file, use this file as my input, and then get rid of the file.

Answer 1

One solution is with the the builtin read command.

 read -r -p 'Please enter your favorite editor' editor
 echo "You have enter $editor"

Now the value is in the $editor" variable, next step would be to test if there is indeed an editor that is installed or within your PATH.

if type "$editor" >/dev/null 2>&1; then
   command "$editor" ENTER_THE_FILE_YOU_WANT_TO_EDIT
else
   echo "$editor no such file or directory!" >&2
   exit 127
fi

see

help type
help command

The 127 exit status is what the shell will exit if there is no executable, alias, function. have a look at

 man 1p exit

Answer 2

You can use vipe with nothing (or some default text) as input:

% foo=$(echo | vipe)
# opens an editor, I add `foo bar`
% echo "$foo"
foo bar

vipe will take care of creating the temporary file and deleting it.