Linux Sort command

I would like to know which sorting algorithm the linux SORT command uses开发者_JAVA技巧?

mergesort

It¹ uses mergesort rather than quicksort or heapsort for two reasons:

• mergesort is a stable sort and typically the efficient quicksort implementations are not
• while it may do more swaps or moves it does fewer comparisons and so tends to work better with text input

^{1. Linux distros are free to choose their own sort utility but I imagine virtually all use GNU sort so I have described that.}

An External R-Way merge sort according to Algorithm details of UNIX Sort Command. Found via this stackoverflow question.