------------------------------------------------------------------------
PROBLEM: Identify files with zero length and delete them
------------------------------------------------------------------------

$ touch a b c
$ > d 
$ cat > 1
Hello Kitty
cntrl D

$ ls -l
total 8                      #this line appears only with "ls -l" or "ls -l *"
-rw-r--r--  1 srk  staff  7 Nov 12 21:39 1
-rw-r--r--  1 srk  staff  0 Nov 12 22:13 c
-rw-r--r--  1 srk  staff  0 Nov 12 22:13 b
-rw-r--r--  1 srk  staff  0 Nov 12 22:13 a
-rw-r--r--  1 srk  staff  0 Nov 12 22:13 d

$ ls -l | 'awk $5==0{print "rm " $9}' | sh
$ ls -l | 'awk $5==0{print "rm " $9}' | sh -x   (tracing on)