Shell Programming and Scripting

file-1.pdf
file-2.pdf
file-3.pdf
file-4.pdf
file-5.pdf
file-6.pdf
file-7.pdf

file-2001.pdf
file-2003.pdf
file-2005.pdf
file-2007.pdf
file-2009.pdf
file-2011.pdf
file-2013.pdf
file-2015.pdf

#!/bin/bash

files=`find . -name 'kay_even*.png.pdf'` 

digits=2001
for fl in $files ; do
  printf "$fl.$digits\n"
  digits=$(($digits + 2))
done

#!/bin/bash

files=`find . -name 'kay_even*.png.pdf'` 

digits=2001
for fl in $files ; do
  fname=`echo $fl | awk 'BEGIN {FS=".png.pdf"} {print $1}'`
  printf "$fname.$digits.png.pdf\n"
  digits=$(($digits + 2))
done

#!/bin/bash

files=`find . -name 'kay.even*.png.pdf'` 

digits=2001
for fl in $files ; do
  fname=`echo $fl | awk 'BEGIN {FS=".png.pdf"} {print $1}'`
  fnew=`echo $fname | awk 'BEGIN {FS="."} {print $1"."$2"."$3}'`
  printf "fname: $fname\n"  
  printf "fnew: $fnew\n"  
  printf "$fnew.$digits.png.pdf\n"
  digits=$(($digits + 2))
done

#!/bin/bash

files=$(find . -name "kay.even*.png.pdf")

num=2001
for fl in $files
do
   prefix=${fl%%[0-9]*}
   suffix=${fl##*[0-9]}
   ((num+=2))
   echo mv $fl $prefix$num$suffix
done

file-1.pdf
file-2.pdf
file-3.pdf
file-4.pdf
file-5.pdf
file-6.pdf
file-7.pdf