function os {
      export OPER_SYS_1="`uname -s`"
      export OPER_SYS_2="`cat /etc/issue | head -n 1`"
      export KERN_INFO="`uname -r`"
      echo -ne "\033[31mOS:\033[0m " && echo "$OPER_SYS_1, $OPER_SYS_2"
      echo -e "\033[32mKernel:\033[0m $KERN_INFO"
      }

function hw () {
   export MOBO_MAN="`sudo dmidecode --type baseboard | grep 'Manufacturer' | cut -d' ' -f2-`"
   export MOBO_MOD="`sudo dmidecode --type baseboard | grep 'Product' | cut -d' ' -f3-`"
   export CPU="`cat /proc/cpuinfo | grep 'model name' | cut -d' ' -f3-`"
   export RAM_TOTAL_KB="`cat /proc/meminfo | grep MemTotal | awk '{print $2}'`"
   export HDD_INFO="`sudo fdisk -l | grep Disk | grep -v identifier`"
   echo -e "\033[1;34mHardware\033[0m:"
   echo " * Motherboard:"
   echo " * Manufacturer: $MOBO_MAN"
   echo " * Model: $MOBO_MOD"
   echo " * CPU(s):"
   echo "$CPU"
   echo " * Total RAM: $(($RAM_TOTAL_KB / 1024)) MB"
   echo " * HDD info: "
   echo "$HDD_INFO"
   echo

  alias system="os && hw"

Colored prompt

PS1='${debian_chroot:+($debian_chroot)}\[\033[01;31m\]\u@\h\[\033[00m\]:\[\033[01;34m\]\w\[\033[00m\]\$ '

#vi $HOME/.bashrc
export HISTTIMEFORMAT=”%h/%d - %H:%M:%S “

 lsnew() { ls -lt ${1+"$@"} | head -20; }

#!/bin/bash

cr='*'
if [ -z $3 ]; then cr=$3; fi

for f in `find $1/$3 -type f | sed "s|$1/||"`
do
  printf "===!%-76s" "$f!" | tr ' !' '= '; echo
  diff $1/$f $2/$f | sed -e "s/^</$1: /" -e "s/^>/$2: /"
done

instead of $RANDOM use ..

SEED=$(head -c4 /dev/urandom | od -t u4 | awk '{ print $2 }')
((N=SEED%N))

or

SEED=$(head -1 /dev/urandom | od -N 1 | awk '{ print $2 }') 
((N=SEED%N))