Remove windows newline in vim

Or say, remove the “^M” character at the end of lines in vim, the original post is here: http://www.tech-recipes.com/rx/150/remove-m-characters-at-end-of-lines-in-vi/

To remove the ^M characters at the end of all lines in vi, use:

:%s/^V^M//g

The ^v is a CONTROL-V character and ^m is a CONTROL-M. When you type this, it will look like this:

:%s/^M//g

In UNIX, you can escape a control character by preceeding it with a CONTROL-V.

Minus sign in path

If a linux folder has minus (“-“) sign as the first character, here’s how to delete it: $ rm – -2345

Hadoop job submission notes

The original post is here: http://grepalex.com/2013/02/25/hadoop-libjars/ Main point:

  1. add libjars to the options:

         $ export LIBJARS=/path/jar1,/path/jar2
     $ hadoop jar my-example.jar com.example.MyTool -libjars ${LIBJARS} -mytoolopt value

  2. Make sure your code is using GenericOptionsParser

    public static void main(final String[] args) throws Exception { Configuration conf = new Configuration(); int res = ToolRunner.run(conf, new com.example.MyTool(), args); System.exit(res); } public class SmallFilesMapReduce extends Configured implements Tool { public final int run(final String[] args) throws Exception { Job job = new Job(super.getConf()); … job.waitForCompletion(true); return …; } }

  3. Use HADOOP_CLASSPATH to make your third-party JAR’s available on the client-side

     $ export LIBJARS=/path/jar1,/path/jar2
 $ export HADOOP_CLASSPATH=/path/jar1:/path/jar2
 $ hadoop jar my-example.jar com.example.MyTool -libjars ${LIBJARS} -mytoolopt value

How to setup ssh default settings

Create a file at ~/.ssh/config with the following content:

user stanley
host mymac
    hostname mymac.corp.stanley.com

The above setting will set the default user name to all hosts as “stanley”; and then set the host alias “mymac” to the actual host “mymac.corp.stanley.com”;

This alias is different from the /etc/hosts file that this alias will only affect the ssh command; if you ping “mymac”, it will still warn you that this host is not known;

You can also set other setting here in the same file, please refer to ssh config for more information;

How to enable git alias

Create a file at ~/.gitconfig with the following content:

[alias]
    co = checkout
    br = branch
    cm = commit
    pl = pull
    st = status

How to allow maven to ignore all ssl error

The original source is here: http://stackoverflow.com/questions/21252800/maven-trusting-all-certs-unlimited-java-policy

The solution is to add the following attributes to the maven command line:

-Dmaven.wagon.http.ssl.insecure=true -Dmaven.wagon.http.ssl.allowall=true