Use environment variable in .inputrc keybinding

Question

I'd like to add a keybinding to my .inputrc that puts the value of an environment variable, USER, on the command line.

I tried all kinds of escaping but the string $USER is written verbatim to the command line, not the value of that environment variable.

$if mode=vi
  # Keymaps when we are in insert mode
  set keymap vi-insert

  # Insert path before mountpoint
  "C-e": "/run/media/$USER"

Is there a reasonable way to do this with .inputrc or am I better off using other means like .bashrc?

Answer 1

User meuh's tip to use shell-expand-line led me to this solution which puts the environment variable's value on the command line:

$if mode=vi
  # Keymaps when we are in insert mode
  set keymap vi-insert

  # Expand variables like ~ and $USER to their values
  "\C-a": shell-expand-line
  # Insert path before mountpoint, then expand the variable
  "\C-e": "/run/media/$USER/\C-a"

Now, pressing Ctrl+e results in /run/media/me/ on the command line.

Answer 2

Inserting the literal string $USER rather than the expanded value of the USER variable may not make a big difference, as the variable is likely defined with the proper value (assuming a Linux system) and would be expanded by the shell.

---

This answers an earlier incarnation of the question:

You can not use environment variables in .inputrc.

To incorporate the username of the current user in bash's primary prompt, set PS1 to a value containing the escape sequence \u.

See the section labelled "PROMPTING" in the bash manual.