Little of BASH knowledge
Initialization files
.bash_profile
.bashrc

If you want to do some additional initialization. Create file like this

~/.myenv

PATH=$PATH:/root/bin:/sbin:/usr/sbin
export PATH

and issue command
source .myenv

vystupy
vsetko na /dev/null vsetky shelly okrem sh
program >& /dev/null
vsetko na /dev/null sh aj bash
program &> /dev/null

program 2>errorr.msg >standard.out

copying of whole directories
cd /usr
tar cf - . | (cd /mnt/add; tar xvf -)

running two jobs in the same time
dialup up ppp2 & firew 1 &
runs both jobs in background

using rsh
rsh vladopc tar cf - /home/jakub | (cd; tar xvf -)
will copy directory /home/jakub from vladopc to user's home directory

arithmetics
#!/bin/sh
echo Testing the arithmetics
C=1

while [ $C -lt 15 ];do
  echo $C
  C=`expr $C + 1`
done

C=1
while [ $C -lt 15 ];do
 echo $C
  C=$[ $C+1 ]
done