Test for White Space
DESCRIPTION:
Tests whether strings consist of only white space.
USAGE: 
is.all.white(x, empty=T)
REQUIRED ARGUMENTS:
x:
character vector.
OPTIONAL ARGUMENTS:
empty:
logical flag: if TRUE, the empty string ("") will be considered white space.
VALUE:
logical vector of the same length as x, whose i'th element is TRUE if string x[i] consists of only white space. This is defined as any combination of spaces and/or tabs.
SEE ALSO:
character , nchar , paste .
EXAMPLES: 
  s
[1] "some string" " \t "      ""


  is.all.white(s)
[1] F T T


  is.all.white(s, empty=F)
[1] F T F