[HADOOP-7325] hadoop command - do not accept class names starting with a hyphen

• Type: Improvement
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: 0.22.0
• Component/s: scripts
• Hadoop Flags: Reviewed
• Assignee: Brock Noland
• Reporter: Brock Noland
• Created: 24/May/11 01:21
• Updated: 29/Jul/11 20:55
• Resolved: 06/Jun/11 20:58

Description

If this is committed I will look at patches for hdfs and mapred.

When teaching a good portion of the students in every single class execute:

$ hadoop -fs ls /

The -fs is passed directly to the JVM and the JVM fails to start:

$ ./bin/hadoop -fs ls /
Unrecognized option: -fs
Could not create the Java virtual machine.

Which is confusing and typically requires explanation. The attached patch improves that behavior:

$ ./bin/hadoop -fs ls /
Error: No command named `-fs' was found. Perhaps you meant `hadoop fs'

The only risk I can see is if someone is abusing the implementation of hadoop command doing something like so:

$ ./bin/hadoop -Xmx1g  org.apache.hadoop.util.RunJar
RunJar jarFile [mainClass] args...

The hadoop command does not appear to advertise allowing JVM options before the classname.

Issue Links

• incorporates: HADOOP-7491 hadoop command should respect HADOOP_OPTS when given a class name