How to remove 2 characters from the beginning of a string after using filename-modifiers?

Question

How to remove 2 characters from the beginning of a string after using filename-modifiers? So assume that I have a files that looks like this:

/home/drskoolie/projects/examples/ex40.c

/home/drskoolie/projects/examples/ex1.c

What I want is to get the number 40 and 1 out of the file names respectively using filename-modifiers (this is later going to a function that will send it to another tmux window). Writing this command gets me almost there: :!echo '%:p:t:r'

ex40

ex1

How do I now remove the first two characters here to get:

40 

1

Answer 1

Any of the following would work with your specific examples:

:echo expand('%:p:t:r')->matchstr('\d\+$')
:echo expand('%:p:t:r')->trim('ex', 1) " the third direction argument might be new?
:echo expand('%:p:t:r')[2:]

Answer 2

Probably not the best solution, but should work :)

Command

!echo $(var=%< && echo ${var/ex/})

Explanation

1. starts subshell and asigns %< to var (%< means current file without extenction)
2. echo the variable var with a command substitution, 'ex' -> ' '

In short: Echo current filename without extenction and replace 'ex' with nothing.

Endword

Hope this helped you :)