Shell Programming and Scripting

echo aaaabbcaa | sed 's/\(.\)\1*/& /g' | awk '{for(i=1; i<=NF; i++) $i=substr($i,1,1) length($i)}1' OFS=

$ ip="aaa[b]"
$ op=$(echo "$ip" | awk '{while (/./) {c=substr($0, 1, 1); match($0, c "*", a); printf c RLENGTH; sub(a[0], "")}}')
awk: cmd. line:1: (FILENAME=- FNR=1) fatal: Unmatched [, [^, [:, [., or [=: /[*/

$ ip="aaa???bbb"
$ op=$(echo "$ip" | awk '{while (/./) {c=substr($0, 1, 1); match($0, c "*", a); printf c RLENGTH; sub(a[0], "")}}')
$ echo $op
a3?3?2?1b3

ip="aaa.bbb"
$ op=$(echo "$ip" | awk '{while (/./) {c=substr($0, 1, 1); match($0, c "*", a); printf c RLENGTH; sub(a[0], "")}}')
$ echo "$op"
a3.4

ip=aaaabbcaa
op=
for s in `echo $ip |sed -r 's/((\w)\2*)/\1 /g'; do  op=$op${s:0:1}${#s}; done

# op= a4b2c1a2

#!/bin/sh
 ip=aaaabbcaa
 op=
 for s in `echo "$ip" | sed 's/\(\(.\)\2*\)/\1 /g'`
 do
  del=${s#?}
  op=$op${s%$del}${#s}
 done
 echo "$op"

#!/bin/bash
ip=aaaabbcaa
len=${#ip}
lchar=${ip:0:1}
for((i=1; i<=$len; i++))
do
  ((found++))
  char=${ip:i:1}
  if [[ $char != $lchar ]]
  then
    op=$op$lchar$found
    found=0
    lchar=$char
  fi
done
echo "$op"