How to set up sending mail with an attachment, where the name of the attachment always changes?

Question

bash

Please tell me how to implement.

I have a script that sends a message with an attachment

#!/bin/bash
for I in `cat list_adresses`; do cat body | mutt -e "set content_type=text/html" -a 
"/path/to/directory/File_name_29.04.21" -s "Тема письма" -- $I < body;echo $I;sleep 1 ;done

The whole thing is that the file name always changes, namely the date in the file name changes. Today _29.04.21, tomorrow _30.04.21.

How to set up an attachment so that the script makes attachments based on the first part of the file name -- File_name

Answer 1

In general, it's very simple to
make a variable
attach=$(ls /path/to/file/ | grep File_name)
AND put the variable in the attachment
-a "/path/to/file/$attach"

Answer 2

if the date changes in a predictable way, i.e. it always matches "today", then use the date.
File_name_`date +%d.%m.%y`"