do while loop

Shell Programming and Scripting
1

Hi Folks,

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

...
....

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

I gone through tutorial site , says

while [ "$*" != "" ]
do
  function1
  function2
done

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

2

All depend on your shell
For bash a simple do/while example look like:

unset i
while (( i++ < 3))
  do 
      echo $i
done
unset i
3

That is non-standard:

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

The standard syntax is:

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:

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