title: Unable to successfully execute some commands in Cygwin
body: <p>I installed Cygwin64 in my 64-bit Windows 7 machine. The following commands failed executing, however, by displaying the error messages below. Could you help providing a resolution please?</p>
  
  <pre><code>$ ll
  -bash: ll: command not found
  
  $ clear
  -bash: clear: command not found
  </code></pre>
  
  <p>However, the command ls -l worked...</p>
  
  <pre><code>$ ls -l
  total 0
  </code></pre>
  
  <p>Also i tried by un-commenting the following line in .bashrc file in my home dir -</p>
  
  <pre><code># alias ll='ls -l'
  </code></pre>
  
  <p>But it didn't help either!</p>