$ alias perle
alias perle='perl -Mstrict -Mwarnings -Mautodie=:all -MCarp::Always -E'

##</code><code>##

$ cat > pm_11133571.dat
234
asdf
quit
ignore

##</code><code>##

ken@titan ~/tmp
$ perle 'my $line; while ( (print "list of letters: "),$line=<>, $line !~ /\s*quit|exit|q\s*$/i) { print "doing something with $line\n"}' pm_11133571.dat
list of letters: doing something with 234

list of letters: doing something with asdf

list of letters:
ken@titan ~/tmp

##</code><code>##

$ cat > pm_11133571_2.dat
234
asdf
ignore

##</code><code>##

$ perle 'my $line; while ( (print "list of letters: "),$line=<>, $line !~ /\s*quit|exit|q\s*$/i) { print "doing something with $line\n"}' pm_11133571_2.dat
list of letters: doing something with 234

list of letters: doing something with asdf

list of letters: doing something with ignore

Use of uninitialized value $line in pattern match (m//) at -e line 1, <> line 3.
 at -e line 1, <ARGV> line 3.
Use of uninitialized value $line in concatenation (.) or string at -e line 1, <> line 3.
 at -e line 1, <ARGV> line 3.
list of letters: doing something with
list of letters: