The use of nuls, instances of x'00', as padding characters long antedates the PC and the C programming language. (COBOL programmers call them LOW VALUES) The chief argument for the use of nuls is that they compare lower than any other byte values.
A number of ASCII and EBCDIC control characters have code points that are smaller in value, compare/sort lower than, an ASCII space, x'20', or an EBCDIC blank, x'40', respectively. Their appearance in a string can thus have bizarre consequences for its position in an ordered sequence when spaces/blanks are used as padding characters. That said, the notion that mainframe "purity" should be considered in taking technical decisions, that we should eschew anything the PC people use as a contaminant, seems to me to be a surpassingly silly one. John Gilmore, Ashland, MA 01721 - USA
