[Trisquel-users] Re : Another uniq -u feature emerges

[lcerf]

Again: 'sort -u' equates to 'sort | uniq'; it does not equate to 'sort | uniq  
-u', because "used by itself, -u causes ‘uniq’ to print unique lines, and  
nothing else".

There is no need to reverse engineer 'uniq': just read its documentation:
$ info uniq