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https://issues.apache.org/jira/browse/HADOOP-8989?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13585968#comment-13585968
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Daryn Sharp commented on HADOOP-8989:
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Initial comments:
* Why is {{setCommandFactory}} exposed, and why is {{FsShell}} setting it in
the instance?
* Use of {{static}} blocks is discouraged because it leads to bizarre problems
during class loading. Is there an easy way to avoid them?
* "recognised" should be "recognized"
* You can retrieve {{options = cf.getOpts}} instead of individually querying
each option and building a new set.
* Why is {{parsePathData}} checking for {{(arg == null)}}? That shouldn't
happen since {{isEmpty}} is already being checked?
* {{processPaths}} really shouldn't be overridden. It was only exposed for
some difficult to handle {{ls}} behavior. The logic should be split into
{{recursePath}} and {{processPath}}.
* I'd suggest against making the expression classes public.
I still need to study the expression handling.
> hadoop dfs -find feature
> ------------------------
>
> Key: HADOOP-8989
> URL: https://issues.apache.org/jira/browse/HADOOP-8989
> Project: Hadoop Common
> Issue Type: New Feature
> Reporter: Marco Nicosia
> Assignee: Jonathan Allen
> Attachments: HADOOP-8989.patch, HADOOP-8989.patch, HADOOP-8989.patch,
> HADOOP-8989.patch, HADOOP-8989.patch, HADOOP-8989.patch, HADOOP-8989.patch,
> HADOOP-8989.patch
>
>
> Both sysadmins and users make frequent use of the unix 'find' command, but
> Hadoop has no correlate. Without this, users are writing scripts which make
> heavy use of hadoop dfs -lsr, and implementing find one-offs. I think hdfs
> -lsr is somewhat taxing on the NameNode, and a really slow experience on the
> client side. Possibly an in-NameNode find operation would be only a bit more
> taxing on the NameNode, but significantly faster from the client's point of
> view?
> The minimum set of options I can think of which would make a Hadoop find
> command generally useful is (in priority order):
> * -type (file or directory, for now)
> * -atime/-ctime-mtime (... and -creationtime?) (both + and - arguments)
> * -print0 (for piping to xargs -0)
> * -depth
> * -owner/-group (and -nouser/-nogroup)
> * -name (allowing for shell pattern, or even regex?)
> * -perm
> * -size
> One possible special case, but could possibly be really cool if it ran from
> within the NameNode:
> * -delete
> The "hadoop dfs -lsr | hadoop dfs -rm" cycle is really, really slow.
> Lower priority, some people do use operators, mostly to execute -or searches
> such as:
> * find / \(-nouser -or -nogroup\)
> Finally, I thought I'd include a link to the [Posix spec for
> find|http://www.opengroup.org/onlinepubs/009695399/utilities/find.html]
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