Shell Programming and Scripting

As has been pointed out already, avoiding external commands will speed up the script considerably.

I use this shell function to abbreviate numbers. The result is stored in $_ABBREV_NUM to avoid using command substitution for the result.

Code:

_abbrev_num() {
    case $1 in
        *.*) set -- ${1%%.*} ;;
    esac
    case ${#1} in
         1|2|3|4) _ABBREV_NUM=$1 ;;
             5|6) _ABBREV_NUM=$(( ($1 + 500) / 1000 ))K ;;
           7|8|9) _ABBREV_NUM=$(( ($1 + 500000) / 1000000 ))M ;;
        10|11|12) _ABBREV_NUM=$(( ($1 + 500000000) / 1000000000 ))G ;;
        13|14|15) _ABBREV_NUM=$(( ($1 + 500000000000) / 1000000000000 ))T ;;
        *) _ABBREV_NUM="HUGE" ;;
    esac
}

The same logic could be used in an awk function if you want to rewrite the entire script in awk.

Or you could install the GNU utilities. Often Solaris has them installed with a 'g' in front of the name, e.g., 'gls'.