digit grouping

digitgrouping.bash

#DECIMALSEP='\.' # usa                                                                                                               
DECIMALSEP=','   # europe
    
#THOUSSEP=','  # usa
#THOUSSEP='\.' # europe
#THOUSSEP='_'  # underscore
#THOUSSEP=' '  # space
THOUSSEP=' '   # thinspace
    
# group before decimal separator
#GROUPBEFDS=4   # china
GROUPBEFDS=3    # europe and usa
    
# group after decimal separator
#GROUPAFTDS=5   # used by many publications 
GROUPAFTDS=3
    
    
function digitgrouping {
# FIXME: This is a workaround: BEGINNING has to be marked (and after                                                                
# alteration removed) for the first number to be spaced correctly (1234
# should be 1 234, and that only works if something is in front of that
# number).
sed -e 's%^%BEGINNING&%' \
  -e '
  s%\([0-9'"$DECIMALSEP"']\+\)'"$THOUSSEP"'%\1__HIDETHOUSSEP__%g
  :restartA ; s%\([0-9]\)\([0-9]\{'"$GROUPBEFDS"'\}\)\(['"$DECIMALSEP$THOUSSEP"']\)%\1'"$THOUSSEP"'\2\3% ; t restartA
  :restartB ; s%\('"$DECIMALSEP"'\([0-9]\{'"$GROUPAFTDS"'\}\'"$THOUSSEP"'\)*\)\([0-9]\{'"$GROUPAFTDS"'\}\)\([0-9]\)%\1\3'"$THOUSSEP"'\4% ; t restartB
  :restartC ; s%\([^'"$DECIMALSEP"'][0-9]\+\)\([0-9]\{'"$GROUPBEFDS"'\}\)\($\|[^0-9]\)%\1'"$THOUSSEP"'\2\3% ; t restartC
  s%__HIDETHOUSSEP__%\'"$THOUSSEP"'%g' \
  -e 's%^BEGINNING%%'

}