title: Bash "source" command returns the wrong concatenated string
body: <p>I have a configuration file like this:</p>
  
  <pre><code>//filename : stat.conf
  LAS_SERVER="127.0.0.1"
  LAS_PORT=3306
  LAS_USER=root
  LAS_PWD=root
  LAS_DB=test
  CONN_STR_LAS_DB="-h$LAS_SERVER -P$LAS_PORT -u$LAS_USER -p$LAS_PWD $LAS_DB"
  </code></pre>
  
  <p>Now I run the <code>source</code> command like this:</p>
  
  <pre><code>$ source ./stat.conf
  
  $ echo $CONN_STR_LAS_DB
  testot.0.1
  </code></pre>
  
  <p>You can see that the result is wrong. not in our expectation.</p>
  
  <p>In contrast, I can get the right result if I run the command in the shell like this:</p>
  
  <pre><code>$ LAS_SERVER="127.0.0.1"
  $ LAS_PORT=3306
  $ LAS_USER=root
  $ LAS_PWD=root
  $ LAS_DB=test
  $ CONN_STR_LAS_DB="-h$LAS_SERVER -P$LAS_PORT -u$LAS_USER -p$LAS_PWD $LAS_DB"
  $ echo $CONN_STR_LAS_DB
  -h127.0.0.1 -P3306 -uroot -proot test
  </code></pre>
  
  <p>This is the right result.</p>
  
  <p>So, my question is: why I got the wrong result when using "source ./stat.conf" ?</p>
  
  <p>I tested the same operation on another computer, I can get the right result. Is there anything that I missed to config on my computer?</p>
  
  <p>My OS is CentOS 5.</p>