# **************************************************************

# This function check if the reference is a SCALAR.

#

#  @example: print "ERROR: A SCALAR is needed\n" if ( !is_string(\$string) );

sub is_string {

my $ref = shift;

return 0 unless ref $ref;

if ( $ref =~ /^SCALAR/ ) { return 1; } else { return 0; }

}