title: Unix sort of two columns of tab-delimited file not recognizing columns as unique
body: <p>I am trying to sort a tab-delimited file by two columns using the following command:<br>
  <code>sort -k1,1 -k2,2 file.txt</code>
  but sort is combining the first and second column into one. </p>
  
  <p>Here is an example of the output:
  <code>
  chr11   25900447    25900461
  chr11   26047696    26047711
  chr1    126169385   126169400
  chr11   26498396    26498411
  </code></p>
  
  <p>On line 3, this chr1 shouldn't be grouped with chr11, but sort is treating the first 1 of the second column as part of the first and sorting the rest of the number accordingly, eg:
  <code>
  chr11   25900447    25900461
  chr11   26047696    26047711
  chr11 &lt;-26169385    126169400
  chr11   26498396    26498411
  </code></p>
  
  <p>I've tried converting to a csv, but exact same issue occurs, where it'll just ignore the , separator.</p>
  
  <p>I am using sort (GNU coreutils) 8.22</p>
  
  <p>Thanks,</p>