Re: [S-mailx] signature

[Stephen Isard]

On Fri, 16 Sep 2022, Steffen Nurpmeso steffen-at-sdaoden.eu |s-nail| wrote:
...
Well ok but the manual includes a fully spelled out example for
on-compose-splice:
  define ocs_signature {
    read version
    echo '~< ~/.mysig' # '~<! fortune pathtofortunefile'
  }
  set on-compose-splice=ocs_signature

This works, but I don't actually understand how.  The man page says that 
'read' reads a line from standard input and assigns it to the given 
variable.  What is standard input going to be in this case?  Is it the 
output of echo?  The given variable is 'version', which is read-only, so 
can't get assigned to.  What causes the quoted string to get evaluated?

Stephen Isard