RE: Backquote Mystery

[Com MN PG P E B Consultant 3]

> Try echo "$e".  Then read about Word Splitting in the Bash manual.

Good point. Since no word splitting occurs within "$e", it is
expanded to a string containing newlines:

$ echo $e   # Expansion without quotes -> word splitting
x sub: f
$ echo "$e" # Expansion with quotes -> no word splitting
x

sub:
f

grep then matches the empty line. Indeed, one can reproduce this
with a much simpler example:

$ u=$(printf 'ab\n\ncd\n')        
$ echo xx|grep "$u"
xx

So we don't have a mystery here, but rather an undocumented feature 
of grep (or at least not documented in the man pages of *my*
version of grep): If the pattern is a string containing newline 
characters, grep matches each of these lines in order to every line 
in the input file, until a match is found.

Thank you for pointing me into the right direction.

Ronald
-- 
Ronald Fischer (phone +49-89-63676431)
mailto:mn-pg-p-e-b-consultant-3.com@siemens.com