SFTP Message: Received message too long

Using sftp to access a remote server I had access to, I was presented with the below error message:

  prystasj@prystasj:~/workspace$ sftp somehost
  Received message too long 1231953966
  prystasj@prystasj:~/workspace$

However, I was able to ssh just fine:

  prystasj@prystasj:~/workspace$ ssh somehost
  In .bashrc
  In .bash_profile
  prystasj@somehost:~$

The key was that my login scripts, .bashrc and .bash_profile produced output as shown above, which was intentional as I was trying to once demonstrate the difference between a login and non-login shell to myself to see which files were sourced. After removing the output-producing commands from the files, I was able to sftp like normal.

Answering Yes to Prompts Automatically

The yes command can be used to pipe a series of y's to another command, so that the user does not have to wait to be prompted during the command's execution.

For example, after a Linux install, I went to use CPAN for the first time to install the File::Find::Rule module.

  prystasj@prystasj:~$ cpan -i "File::Find::Rule"

  CPAN is the world-wide archive of perl resources.
  ...
  Would you like me to configure as much as possible automatically? [yes]

While answering yes above will configure CPAN automaticaly, I'll still be prompted to answer questions regarding the module's dependencies:

  Writing Makefile for File::Find::Rule
  Falling back to other methods to determine prerequisites
  ---- Unsatisfied dependencies detected during ----
  ----     RCLAMP/File-Find-Rule-0.32.tar.gz    ----
      Number::Compare [requires]
      Text::Glob [requires]
  Shall I follow them and prepend them to the queue of modules
  we are processing right now? [yes]

To automatically answer yes to every question, you can pipe the output of the yes command to the prompting command. For example:

  prystasj@prystasj:~$ yes | cpan -i "File::Find::Rule"

Now I can install the module without watching the command's progress.

Groovy: Retrieving XML Element Attributes in a Map

The Groovy script below is a little test I came up to help me remember how to grab element attributes from an XML document. In the example message, I want the attributes from the request element in a Map:

  def message = """<message>
    <request file="/home/prystasj/file.txt" type="txt" />
  <message>"""

  def xml = new XmlParser().parseText(message)
  def attrs = xml.request[0].attributes()

  println "Class: ${attrs.getClass().getName()}"
  println "Size: ${attrs.size()}"
  println "Attributes: $attrs"
  println "File: ${attrs.file}"
  println "Type: ${attrs.type}"

The key that tripped me up was that I needed to grab the first request element (indexed at 0) in the assignment to attrs.

The output from the script:

  Class: java.util.LinkedHashMap
  Size: 2
  Attributes: [file:/home/prystasj/file.txt, type:txt]
  File: /home/prystasj/file.txt
  Type: txt