bug#36820: grep "[[:cntrl:]]" /proc/1/cmdline works on 2.20 but not 3.3

[Jeff Chua]

# using grep 2.20 ...
# grep "[[:cntrl:]]" /proc/1/cmdline
Binary file /proc/1/cmdline matches

# using grep 3.3 or above 2.20 ...
# grep "[[:cntrl:]]" /proc/1/cmdline
... nothing returned



My best.,
Jeff