vimrc command to add uid in insert mode

Question

In my .vimrc I have the following, which in Vim Visual mode inserts an unique alphanumeric string.

vnoremap <leader>u :!pwgen -A 8 1<CR>

For convenience, I want to do the same thing in Vim Insert mode: something like this (not working: .vimrc):

iabbrev uuid `pwgen -A 8 1`

where the abbreviation uuid (or :uid: or similar) triggers the BASH pwgen command (e.g replacing uuid with moh6sei5).

Edit

Per the comment immediately following mentioning Defining linux command inside vim abbreviations

the issue is that strtime (there) is a native Vim function (:h strftime), whereas pwgen is a BASH function. In .vimrc:

works:

iabbrev xxx <C-r>=strftime('%c')<CR>
" Sun 02 Oct 2022 11:03:58 AM PDT

does not work:

iabbrev uidd <C-r>=pwgen -A 8 1<CR>
iabbrev uidd <C-r>=!pwgen -A 8 1<CR>
iabbrev uidd <C-r>=`pwgen -A 8 1`<CR>
...

Does this answer your question? [Defining linux command inside vim abbreviations](https://stackoverflow.com/questions/57338955/defining-linux-command-inside-vim-abbreviations) — Andy Lester, Oct 02 '22 at 17:44
Thank you for the suggestion; in response please see edit to Question, above. I am also using `SnipMate`, but I find that package to be dated and buggy, so I am trying to move away from it (or alternatives: `UltiSnips`, ...) — Victoria Stuart, Oct 02 '22 at 18:10

score 3 · Accepted Answer · answered Oct 02 '22 at 19:15

inoreabbrev <expr> uuid system('pwgen -A 8 1')->trim()

Breakdown:

<expr> tells Vim that the right hand side of the abbreviation is to be evaluated as a Vim expression.
Since pwgen is an external command, you need :help system() to capture its output.
External commands often end with a newline character so you need to :help trim() it.

Victoria Stuart · Answer 2 · 2022-10-02T22:19:31.457

This works, .vimrc:

inoremap <F3> <c-r>=trim(system('pwgen -A 8 1'))<cr>

Test: Insert mode, typing apple <F3> banana gives apple ipav7lier banana, where <F3> is that key. Each <F3> keypress inserts a UID.

system(): Vim system() command (:h system in Vim)
pwgen: BASH alphanumeric password generator command (man pwgen in BASH terminal)
pwgen -A 8 1: lowercase only (-A), 8 characters, 1 password
<F3> : keyboard function 3 key
See also: https://www.grailbox.com/2021/07/insert-uuids-in-vim-neovim/ ... links to (explanation) https://old.reddit.com/r/vim/comments/bnh7su/inserting_the_output_of_an_external_program_inline/

2 Answers2