Here are some shell scripts you will love to try and learn from.

To find all the IP address in /etc directory

find /etc -exec grep '[0-9][0-9]*[.][0-9][0-9]*[.][0-9][0-9]*[.][0-9][0-9]*' {} \;

Another Script

==============

#!/bin/bash
# idelete.sh: Deleting a file by its inode number.

#  This is useful when a filename starts with an illegal character,
#+ such as ? or -.

ARGCOUNT=1                      # Filename arg must be passed to script.
E_WRONGARGS=70
E_FILE_NOT_EXIST=71
E_CHANGED_MIND=72

if [ $# -ne "$ARGCOUNT" ]
then
  echo "Usage: `basename $0` filename"
  exit $E_WRONGARGS
fi  

if [ ! -e "$1" ]
then
  echo "File \""$1"\" does not exist."
  exit $E_FILE_NOT_EXIST
fi  

inum=`ls -i | grep "$1" | awk '{print $1}'`
# inum = inode (index node) number of file
# -----------------------------------------------------------------------
# Every file has an inode, a record that holds its physical address info.
# -----------------------------------------------------------------------

echo; echo -n "Are you absolutely sure you want to delete \"$1\" (y/n)? "
# The '-v' option to 'rm' also asks this.
read answer
case "$answer" in
[nN]) echo "Changed your mind, huh?"
      exit $E_CHANGED_MIND
      ;;
*)    echo "Deleting file \"$1\".";;
esac

find . -inum $inum -exec rm {} \;
#                           ^^
#        Curly brackets are placeholder
#+       for text output by "find."
echo "File "\"$1"\" deleted!"

exit 0