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https://issues.apache.org/jira/browse/HADOOP-3331?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12645711#action_12645711
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Ronen Botzer commented on HADOOP-3331:
--------------------------------------
The [current
documentation|http://hadoop.apache.org/core/docs/current/hdfs_shell.html#test]
(0.18) states the exact opposite from the current behavior:
{noformat}
Usage: hadoop fs -test -[ezd] URI
Options:
-e check to see if the file exists. Return 0 if true.
{noformat}
In fact:
{noformat}
-bash-3.1$ hadoop fs -ls /user/rbotzer/
Found 1 items
-rw-r--r-- 2 rbotzer supergroup 7603 2008-11-06 23:05
/user/rbotzer/testlog
-bash-3.1$ # capture the exit status
-bash-3.1$ ./ec /user/rbotzer/testlog
hadoop fs -test -e /user/rbotzer/testlog
int(1)
{noformat}
> Return code for "hadoop dfs -test" does not match standard return codes from
> System.exit
> ----------------------------------------------------------------------------------------
>
> Key: HADOOP-3331
> URL: https://issues.apache.org/jira/browse/HADOOP-3331
> Project: Hadoop Core
> Issue Type: Bug
> Components: fs
> Environment: All
> Reporter: Mike Dillon
> Priority: Minor
>
> The output of "hadoop dfs -test" does the opposite of what normal Unix
> commands to (which is also the opposite of the recommended return codes in
> the javadocs for System.exit). Normal commands return zero for success and
> non-zero for error, but "hadoop dfs -test" does this opposite. This makes
> writing shell scripts that use "hadoop dfs -test" clunky and unnatural since
> you can't do standard stuff like this:
> {noformat}
> if hadoop dfs -test -e /missing/file/name; then
> # Do something only if the file exists
> else
> # Do something else if the file is missing
> fi
> {noformat}
> Creating a patch for this would introduce a breaking change and would require
> changing the Ant DFS task as well.
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