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# 1  
Old 10-06-2009
Lightbulb do while loop

Hi Folks,

I want to implement do while loop in script for following logic

...
....
Code:
do
{
  function1
  function 2
  result = function 3
} while(result !=0);

I gone through tutorial site , says
Code:
while [ "$*" != "" ]
do
  function1
  function2
done

----
But I want to repeat only if function 3 fails... Please suggest

Last edited by pludi; 10-06-2009 at 09:52 AM.. Reason: code tags please...
# 2  
Old 10-06-2009
All depend on your shell
For bash a simple do/while example look like:
Code:
unset i
while (( i++ < 3))
  do 
      echo $i
done
unset i

# 3  
Old 10-06-2009
Quote:
Originally Posted by danmero
All depend on your shell
For bash a simple do/while example look like:
Code:
unset i
while (( i++ < 3))
  do 
      echo $i
done
unset i


That is non-standard:

Code:
$  while (( i++ < 3))
> do
>   echo $i
> done
dash: cannot open 3: No such file
dash: i++: not found

The standard syntax is:

Code:
while [ $(( i += 1 )) -le 3 ]
do
  echo $i
done

Though that doesn't work in older versions of the standard *BSD shell. To accommodate those, use:

Code:
i=1
while [ $i -le 3 ]
do
  echo $i
  i=$(( $i + 3 ))
done


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