Question

Occasionally, we receive ZIP files from our suppliers that are seemingly corrupted. Attempting to list the contents of a ZIP will trigger an error like this:

    $>unzip -qql JABL_VER_20120808_165910.zip
unzip:  cannot find or open JABL_VER_20120808_165910.zip, JABL_VER_20120808_165910.zip.zip or JABL_VER_20120808_165910.zip.ZIP.

I did a quick read of the unzip man page and coded that snippet to trap the above error

EXIT=`echo $?`
case $EXIT in
> 0-1) echo "Unzip Complete.";;
> *) echo "Unzip Failed.";;
> esac
$>Unzip Failed.

It seems to work. However, there are cases like this one where the error is different:

$>unzip -qql JABL_VER_20120808_175915.zip
  End-of-central-directory signature not found.  Either this file is not
  a zipfile, or it constitutes one disk of a multi-part archive.  In the
  latter case the central directory and zipfile comment will be found on
  the last disk(s) of this archive.
unzip:  cannot find zipfile directory in one of JABL_VER_20120808_175915.zip or
        JABL_VER_20120808_175915.zip.zip, and cannot find JABL_VER_20120808_175915.zip.ZIP, period.

Is there a “surefire” way to trap errors like these?

PS: Not sure if matters but the ZIP files are generated on MS Windows ; We use Red Hat.

Answer 1

exit code 1 isn’t good either,
1 one or more warning errors were encountered, but processing completed successfully anyway. This includes zipfiles
where one or more files was skipped due to unsupported compression method or encryption with an unknown password.

you should try

   unzip -t zipfilename

and only accept exit code 0

why do you have so many errors? ftp’d file in text mode?