http://www.cyberciti.biz/faq/bash-while-loop/
BASH WHILE LOOP SYNTAX
while [ condition ] do command1 command2 command3 done
Example:
#!/bin/bash x=1 while [ $x -le 5 ] do echo "Welcome $x times" x=$(( $x + 1 )) done
#!/bin/bash while : do echo "infinite loops [ hit CTRL+C to stop]" done
Conditional while loop exit with break statement
while [ condition ] do statements1 #Executed as long as condition is true and/or, up to a disaster-condition if any. statements2 if (disaster-condition) then break #Abandon the while lopp. fi statements3 #While good and, no disaster-condition. done