Can't figure out recursion problem in bash/freebsd

David Rawling djr at
Thu Jan 7 23:12:02 UTC 2010

On 8/01/2010 8:47 AM, Bernard T. Higonnet wrote:
> echo starting in `pwd`
> for hoo in *
>   do
>     echo $hoo
>     if [ -d "$hoo" ]
>       then echo pushing $hoo; cd $hoo
>       $0
>       else echo processing $hoo
>     fi;
>   echo going to next item
>   done
> cd ..
> I have tried various minor variations , all to no avail.
> I have no doubt I'm doing something very dumb, but I'm too locked into 
> my vision to see it...
> All help appreciated
> Bernard Higonnet
I am probably the last person you'd want debugging your scripts, but I 
can at least reproduce the problem.

My test folder and file structure:


Luckily, I think I have also derived the solution. The problem appears 
to be the directory stack. Specifically, the output of my revised 
version shows that it's not working in the right folders all the time.

#! /bin/sh

echo Starting in `pwd`

for hoo in *; do
   echo $hoo
   if [ -d "$hoo" ]; then
     echo Pushing $hoo; cd $hoo
     echo Processing file $hoo
   echo Going to next item
cd ..

echo Finishing in `pwd`

By moving the cd command into the if statement, we change back into the 
correct folder at the right time (otherwise the siblings to the first 
directory cannot be found in the for loop, perhaps because the current 
directory has changed mid-execution):

test01# cat /root/
#! /bin/sh

echo Starting in `pwd`

for hoo in *; do
   echo Found item $hoo
   if [ -d "$hoo" ]; then
     echo Pushing $hoo
     cd $hoo
     cd ..
     echo Processing file $hoo
   echo Going to next item

echo Finishing in `pwd`

I think it works - someone brighter than me can tell us both why :). 
Most of the changes you see there are stylistic (eg the placement of 
then/else and do/done) or were for my own clarity in figuring out what 
was being printed where.


David Rawling
Principal Consultant

PD Consulting And Security
7 Virginia Ave
Baulkham Hills, NSW 2153
Mob: +61 412 135 513
Email: djr at

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