For environments where there is no full fledged printf. The below function does a pretty print of numbers with thousand separator
function
#converts given number to pretty format
function pretty_num(){
awk '{ len=length($0); res=""; for (i=0;i<=len;i++) { res=substr($0,len-i+1,1) res; if (i > 0 && i < len && i % 3 == 0) { res = "," res } }; print res }'|sed -e's/-,\(.*\)/-\1/g'
}
output