toprated - sort input by count, with total and percentages

#!/bin/bash
#
# toprated - sort input by count, showing totals and percentages
#
#    Copyright (C) 2012 Rodrigo Silva (MestreLion) <[email protected]>
#
#    This program is free software: you can redistribute it and/or modify
#    it under the terms of the GNU General Public License as published by
#    the Free Software Foundation, either version 3 of the License, or
#    (at your option) any later version.
#
#    This program is distributed in the hope that it will be useful,
#    but WITHOUT ANY WARRANTY; without even the implied warranty of
#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#    GNU General Public License for more details.
#
#    You should have received a copy of the GNU General Public License
#    along with this program. If not, see <http://www.gnu.org/licenses/gpl.html>
#
# Think of it as a sort | uniq -c | sort -rn on steroids ;)
#
# TODO: allow <total> to be printed as last line instead of first
# TODO: allow <other> to be printed in its list position instead of last

#Defauls:
mincount=0
minperc=0
showtotal=1
showperc=1
showother=1
precision=0
totallabel="Total"
otherlabel="Other"

fatal()   { [[ "$1" ]] && echo "$myname: error: $1" >&2 ; exit ${2:-1} ; }
argerr()  { echo "$myname: ${1:-error}" >&2 ; usage 1 ; }
invalid() { argerr "invalid option: $1" ; }
missing() { argerr "missing ${2:+$2 }operand${1:+ from $1}." ; }
integer() { [[ "$1" != *[!0-9]* ]] || argerr "'$1'${2:+ in $2} is not an integer." ; }

usage() {
    cat <<- USAGE
    Usage: $myname [options] [FILE...]
    USAGE
    if [[ "$1" ]] ; then
        cat >&2 <<- USAGE
        Try '$myname --help' for more information.
        USAGE
        exit 1
    fi
    cat <<-USAGE

    Sort input by count, printing totals and percentages. Think of it as
    sort | uniq -c | sort -rn on steroids.

    If FILE is not given, read from standard input. For numeric input
    options, NUM must be a positive integer (digits only). All options
    requiring arguments accept both --option=ARG or --option ARG forms

    Options:
      -h|--help            show this page.

      --min-count=NUM      only print lines with count >= NUM
      --min-perc=NUM       only print lines with count percent >= NUM%

      All lines with count less than any of the above options will be
      grouped together as a single <other> line, printed last by default

      --precision=NUM      use NUM decimal digits for the percentages,
                           default $precision

      --label-total=LABEL  use LABEL for <total> line, default "$totallabel"
      --label-other=LABEL  use LABEL for <other> line, default "$otherlabel"

      --no-perc            do not print percentages
      --no-total           do not print <total> line
      --no-other           do not print <other> line

      --total-last         print <total> line last instead of first *
      --sort-other         print <other> line in sorted position *

      * (above options not yet implemented)

    Examples:

    # Group all lines with count = 1 as "Other"
    $myname --min-count=2

    # Ignore lines with count < 10%
    $myname --min-perc=10 --no-other

    # Behaves (almost*) exactly like sort | uniq -c | sort -nr
    $myname --no-total --no-perc

    * (it still pads counts as if total was present)

    Copyright (C) 2012 Rodrigo Silva (MestreLion) <linux@rodrigosilva.com>
    License: GPLv3 or later. See <http://www.gnu.org/licenses/gpl.html>
    USAGE
    exit 0
}

myname="${0##*/}"
files=()
for arg in "$@"; do [[ "$arg" == "-h" || "$arg" == "--help" ]] && usage ; done
while (( $# )); do
    case "$1" in
    --min-count=*   ) mincount="${1#*=}"             ;;
    --min-perc=*    ) minperc="${1#*=}"              ;;
    --precision=*   ) precision="${1#*=}"            ;;
    --label-total=* ) totallabel="${1#*=}"           ;;
    --label-other=* ) otherlabel="${1#*=}"           ;;
    --min-count     ) shift ; mincount="$1"          ;;
    --min-perc      ) shift ; minperc="$1"           ;;
    --precision     ) shift ; precision="$1"         ;;
    --label-total   ) shift ; totallabel="$1"        ;;
    --label-other   ) shift ; otherlabel="$1"        ;;
    --no-total      ) showtotal=0                    ;;
    --no-perc       ) showperc=0                     ;;
    --no-other      ) showother=0                    ;;
    --              ) shift ; files=( "$@" ) ; break ;;
    -*              ) invalid "$1"                   ;;
    *               ) files+=( "$1" )                ;;
    esac
    shift
done

[[ "$totallabel" ]] || missing "--label-total" "LABEL"
[[ "$otherlabel" ]] || missing "--label-other" "LABEL"
[[ "$mincount"   ]] || missing "--min-count"   "NUM"
[[ "$minperc"    ]] || missing "--min-perc"    "NUM"
[[ "$precision"  ]] || missing "--precision"   "NUM"

integer "$mincount"  "--min-count"
integer "$minperc"   "--min-perc"
integer "$precision" "--precision"

sort "${files[@]}" | uniq -c |
awk -F' ' -v label="$totallabel" '
        {total+=$1; print}
    END {print " ", total, label}' |
sort -nr |
awk -v showtotal=$showtotal -v showperc=$showperc -v showother=$showother \
    -v mincount=$mincount -v minperc=$minperc \
    -v precision=$precision -v label="$otherlabel" -F ' ' --posix '
    function printitem(count, perc, item) {
        printf("%*d %*.*f%% %s\n",cpad,count,ppad,prescision,perc,item)
    }
    BEGIN {
        ppad = 3
        if (precision > 0) ppad += precision+1
    }
    FNR==1 {
        total = $1
        cpad = length($1)+2
    }
    {
        perc = 100*$1/total
        abovemin = (perc >= minperc + 0) && ($1 >= mincount + 0)
        if (abovemin && (FNR>1 || showtotal))
            printitem($1,perc,$2)
        if (!abovemin && showother && FNR>1)
            other += $1
    }
    END {
        if (other > 0) {
            perc = 100*other/total
            printitem(other,perc,label)
        }
    }
'