# Set padding character to the default (" ") if it was not set with -v
# Set ORS to "" to make printing easier
#FNR == NR { if(length > M) M = length; next }
BEGIN { if(D == "") D = " "; ORS = "" }

# Pad each line according current line length (L) and longest line (M)
{
  L = wcL - length;
  for(i=1; i<=int(L/2); i++)
    print D
  print $0
  for(i=1; i<=int(L/2+.5); i++)
    print D
  print "\n"
}