C:\Old_Data\perlp>perl -wE "opendir DIR, 'CSV';say for grep -f, readdir DIR"
dat.txt
DBD_CSV.pl
my_db.txt
my_db_2.txt
o33.csv
o33.txt
o44.txt
o55.csv
text_csv.pl
zip_codes.csv

C:\Old_Data\perlp>perl -wE "opendir DIR, 'CSV';say for grep ! -d, readdir DIR"
csvfile.pl
dat.txt
DBD_CSV.pl
dbd_csv_2tables.pl
mytable
my_db.txt
my_db_2.txt
name_cols_csv.pl
o33.csv
o33.txt
o44.txt
o55.csv
placeholder.pl
pmonk814937.pl
selectall_hashref.pl
test1.txt
test_class_csv.pl
text_csv.pl
using_DBD_CSV.pl
zip_codes.csv

C:\Old_Data\perlp>