$ perl cdiff.pl file1.txt file1.txt
ebrine
        Found in file1.txt at line(s): 3
        Found in file1.txt at line(s): 3
qwerty
        Found in file1.txt at line(s): 1
        Found in file1.txt at line(s): 1
snakegod
        Found in file1.txt at line(s): 2
        Found in file1.txt at line(s): 2
tarot
        Found in file1.txt at line(s): 4
        Found in file1.txt at line(s): 4
$ perl cdiff.pl file1.txt file3.txt
ebrine
        Found in file1.txt at line(s): 3
        Found in file3.txt at line(s): 3
qwerty
        Found in file1.txt at line(s): 1
        Found in file3.txt at line(s): 1, 5
snakegod
        Found in file1.txt at line(s): 2
        Found in file3.txt at line(s): 2
tarot
        Found in file1.txt at line(s): 4
        Found in file3.txt at line(s): 4
$ perl cdiff.pl file1.txt file2.txt
snakegod
        Found in file1.txt at line(s): 2
        Found in file2.txt at line(s): 1
tarot
        Found in file1.txt at line(s): 4
        Found in file2.txt at line(s): 3
Found in file1.txt but not in file2.txt:
        'ebrine' at line(s): 3
        'qwerty' at line(s): 1
Found in file2.txt but not in file1.txt:
        'ordo rosae moriatur' at line(s): 2
        'wrath of hibernia' at line(s): 4
$ perl cdiff.pl file1.txt file4.txt
Fewer values detected in file4.txt than file1.txt
qwerty
        Found in file1.txt at line(s): 1
        Found in file4.txt at line(s): 1
Found in file1.txt but not in file4.txt:
        'ebrine' at line(s): 3
        'snakegod' at line(s): 2
        'tarot' at line(s): 4