language syntax

 for i in 1 2 3 4 5
 do
    echo "Welcome $i times"
 done

 for i in {1..5} ...

 for i in $(seq 1 2 20)

 for (( c=1; c<=5; c++ ))

 if (disaster-condition)
 then
   break       	   # Abandon the loop.
 fi

if (condition)
then
   continue              # Go to next iteration of I in the loop and skip statements3
fi	  

for file in /etc/*
do
   if [ "${file}" == "/etc/resolv.conf" ]
   then
      ...
      break
   fi
done

show 'disc free' space every 10sec:

for i in {1..1000}; do df -h ; echo '______'; sleep 10 ; done;

create a batch of symlinks:

for i in `ls /var/www/`; do echo $i; ln -s /var/www/${i}/traffic/ /var/www/webalizer/${i}; done

remove files, when the list of files is too long for rm: