>perl -MData::Dump=pp -E "pp unpack 'A*', qq<aaaa\t\n >"
"aaaa"

>perl -MData::Dump=pp -E "pp unpack 'a*', qq<aaaa\t\n >"
"aaaa\t\n "

>perl -MData::Dump=pp -E "pp unpack 'a*', qq<aaaa\t\n \0>"
"aaaa\t\n \0"