sh script problem with capturing return code

[Lowell Gilbert]

Fbsd8 <fbsd8 at a1poweruser.com> writes:

> Polytropon wrote:
>> On Tue, 08 Jan 2013 16:30:49 -0500, Fbsd8 wrote:
>>> I can not get the return code from mtree to control
>>> the displaying of a error message.
>>>
>>> The mtree at the end of the script does function correctly
>>> because I can tell from the printed output.
>>>
>>> When mtree prints comments saying "extra" that means the directory
>>> being read does not match the specification file. return code
>>> should be Not equal to zero.
>>>
>>> And when they do match IE: no mtree comments printed, that should
>>> be a return code of zero.
>>>
>>> I tried 2 different ways to capture the return code to no joy.
>>> What I am doing wrong?
>>>
>>> #! /bin/sh
>>> flavor="/a/mtree.std"
>>> echo "flavor = ${flavor}"
>>> /bin/cat  << EOF |
>>> /set type=dir uname=root gname=wheel
>>> .
>>> etc     ignore
>>> ..
>>> root    ignore
>>> ..
>>> usr
>>> home    ignore
>>> ..
>>> local
>>> etc     ignore
>>> ..
>>> ..
>>> ..
>>> ..
>>> EOF
>>>
>>>   mtree -d -u -p "${flavor}"  || \
>>>     echo "Error invalid directories in flavor ${flavor}."
>>>
>>> #mtree -d -p "${flavor}"
>>> #[ $? -eq 0 ] || \
>>> #  echo "Error invalid directories in flavor ${flavor}."
>>> echo "return = $?"
>>
>> It seems that returning 0 is correct in a case as you mentioned.
>> The manual at "man mtree" states:
>>
>> EXIT STATUS
>>      The mtree utility exits 0 on success, and >0 if an error occurs.
>>
>> Question: What _is_ an error here?
>>
>> If you use the source Luke at /usr/src/usr.sbin/mtree/mtree.c,
>> you could find out what combination of options plus circumstances
>> found at runtime could trigger an exit status != 0.
>>
>> The main() functions finishes with exit(status); where status
>> is either set by functions mtree_specspec() or mtree_verifyspec(),
>> or manually to 0 when -U is provided and MISMATCHEXIT (is 2) is
>> encountered.
>>
>> Again from the manual:
>>
>>      -u    Same as -U except a status of 2 is returned if the file hierarchy
>>            did not match the specification.
>>
>>      -U    Modify the owner, group, permissions, and modification time of
>>            existing files to match the specification and create any missing
>>            directories or symbolic links.  User, group and permissions must
>>            all be specified for missing directories to be created.  Corrected
>>            mismatches are not considered errors.
>>
>> However, you're not using -U, but -u, so the last sentence of
>> the description above should be relevant: No error per se,
>> even though the status code should be 2.
>>
>>
>>
>>
> Well I just tested with -U -u together no joy.
> Tested with -U no joy.
>
> My read of the above is -u should cause a return code of 2 when the
> file hierarchy does not match the specification. I don't want -U
> because I am not modifying any content of the directory tree mtree is
> looking at.
>
> I just don't get the point your trying to make.
>
> Oh the other hand are you saying the script code is correct to capture
> the return code but using wrong options with mtree ?

It works fine for me:

    [5023] (lowell-desk) temp> touch foo
    [5024] (lowell-desk) temp> mtree -c > ../out
    [5025] (lowell-desk) temp> if (mtree < ../out ) ; then echo yes ; else echo no ; fi
    yes
    [5026] (lowell-desk) temp> touch foo
    [5027] (lowell-desk) temp> if (mtree < ../out ) ; then echo yes ; else echo no ; fi
    foo changed
            modification time expected Wed Jan  9 02:42:31 2013 found Wed Jan  9 02:42:47 2013
    no
    [5028] (lowell-desk) temp> echo $?
    0
    [5029] (lowell-desk) temp> mtree < ../out
    foo changed
            modification time expected Wed Jan  9 02:42:31 2013 found Wed Jan  9 02:42:47 2013
    [5030] (lowell-desk) temp> echo $?
    2
    [5031] (lowell-desk) temp> touch temp
    [5032] (lowell-desk) temp> mtree -u < ../out
    . changed
            modification time expected Wed Jan  9 02:42:37 2013 found Wed Jan  9 02:49:52 2013 modified
    foo changed
            modification time expected Wed Jan  9 02:42:31 2013 found Wed Jan  9 02:42:47 2013 modified
    temp extra
    [5033] (lowell-desk) temp> echo $?
    2

This is exactly what I would expect, and what you said you weren't
getting. You didn't show what you ran your script on, or what the
results were, so I can't tell you what you're doing wrong -- but compare
my example to yours and I'm sure you'll be able to figure it out.

Good luck.