histogram

#!/bin/bash
set -euf -o pipefail

##
# Histogram on the command line
#
# Credit: Small labs Inc.
# See http://www.smallmeans.com/notes/shell-history/
#
# How it works:
#
#   * sort               Sort, so that similar commands come in groups
#   * uniq -c            Count subsequent items (-c prepends count)
#   * sort -rn           Sort in descending order (reverse)
#   * head -20           Get the 20 most frequent commands
#
#   * awk '!max{max=$1;}{      Everything is nice and in order:
#          r="";               run thru the items, format, pad, print
#          i=s=60*$1/max;
#          while(i-->0){
#            r=r"#";           string concatenation, AWK-style
#          }
#          printf "%15s %5d %s %s",$2,$1,r,"\n";
#        }'
#
# Example:
#
#   history | awk '{print $2}' | histogram
#
# Contact: Joel Parker Henderson (joel@joelparkerhenderson.com)
# License: GPL
# Updated: 2015-01-25
##

sort | uniq -c | sort -rn | awk '!max{max=$1;}{r="";i=s=60*$1/max;while(i-->0)r=r"#";printf "%15s %5d %s %s",$2,$1,r,"\n";}'