What sorting algorithm does qsort use?

Question

I can\'t find any information regarding what sorting algorithm C qsort function uses.

Is it quicksort? It is not mentioned in man.

Answer 1

In complement to James McNellis’s quotation of the standard it is worth noting that GNU’s libc documentation says that

The qsort function derives its name from the fact that it was originally implemented using the “quick sort” algorithm.

and that it decided to use an alternative algorithm, apparently a merge sort.