Hi Jaikiran

From https://docs.oracle.com/en/java/javase/15/docs/specs/man/jar.html

The jar man page includes the following :
 The syntax for the jar command resembles the syntax for the tar command.

Because of the above, I feel that we should support:

———
-C
—dir
—directory
————

The addition of ‘-dir’ adds support for an option used by some of the other 
java command line tools.

I would suggest for the next step is flush/write out your proposed  syntax  as 
it would be included in an updated version of the jar man page.

Given the other java command line tools create the directory if it does not 
exist, I think that is reasonable to propose that.

Your change should not modify the longstanding overwrite behavior of jar.

Another thing to think about is whether there should be any additional output 
when the -v option is specified

In summary, I think you are moving in the right direction.  The next step is to 
make a pass at creating the man page updates so that we can reach consensus on 
the syntax and behavior.

Thank you again for your efforts on this

Best
Lance

On Mar 3, 2021, at 9:40 PM, Jaikiran Pai 
<jai.forums2...@gmail.com<mailto:jai.forums2...@gmail.com>> wrote:


Hello Lance,

On 03/03/21 9:14 pm, Lance Andersen wrote:


Some other things needed to be defined and agreed upon in order to move forward


  *   The behavior if the path does not exist
  *   If the option is specified more than once on the command line
  *   Clarify the behavior if any of the files exist in the specified target 
directory.

One of my previous reply included the details of how I think it should behave 
for 2 of the above cases. I'll paste that here again for easier visibility. As 
for how it should behave if the option is specified more than once, I'll spend 
some time today to see how the jar tool currently behaves for some of the other 
options in this aspect and send back my response. Thank you for your help so 
far. Pasting below my proposal from a previous reply for the other 2 cases:


There are other discussion points around the behavior when the target directory 
exists or does not exist, to ensure there is some consistency with main stream 
tools.

I'm guessing you mean the behaviour of creating a directory (or a hierarchy of 
directories) if the target directory is not present? My testing with the tar 
tool (both on MacOS and CentOS) shows that if the specified target directory 
doesn't exist, then the extract fails. The tar extract command doesn't create 
the target directory during extract. On the other hand, the unzip tool, does 
create the directory if it doesn't exist. However, interestingly, the unzip 
tool creates only one level of that directory if it doesn't exist. 
Specifically, if you specify:

unzip foo.zip -d /tmp/blah/

and if "blah/" isn't a directory inside /tmp/ directory, then it creates the 
"blah/" directory inside /tmp/ and then extracts the contents of the zip into 
it.

However,

unzip foo.zip -d /tmp/blah/hello/

and if "blah/" isn't a directory inside /tmp/ directory, then this command 
fails with an error and it doesn't create the hierarchy of the target 
directories.

Coming to the jimage and the jmod commands, both these commands create the 
entire directory hierarchy if the target directory specified during extract, 
using --dir, doesn't exist. So a command like:

jimage extract --dir /tmp/blah/foo/bar/ jdkmodules

will create the blah/foo/bar/ directory hierarchy if blah doesn't exist in 
/tmp/, while extracting the "jdkmodules" image.

From the user point of view, I think this behaviour of creating the directories 
if the target directory doesn't exist, is probably the most intuitive and 
useful and if we did decide to use this approach for this new option for jar 
extract command, then it would align with what we already do in jimage and jmod 
commands.

One another minor detail, while we are at this, is that, IMO we should let the 
jar extract command to continue to behave the way it currently does when it 
comes to overwriting existing files. If the jar being extracted contains a file 
by the same name, in the target directory (hierarchy) then it should continue 
to overwrite that file. In other words, I don't think we should change the way 
the jar extract command currently behaves where it overwrites existing files 
when extracting.

-Jaikiran

[cid:E1C4E2F0-ECD0-4C9D-ADB4-B16CA7BCB7FC@home]



Lance Andersen| Principal Member of Technical Staff | +1.781.442.2037
Oracle Java Engineering
1 Network Drive
Burlington, MA 01803
lance.ander...@oracle.com<mailto:lance.ander...@oracle.com>



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