1 /* Copyright (c) 2014 Yaakov Selkowitz <yselkowi@redhat.com> */ 2 /* 3 FUNCTION 4 <<qsort_r>>---sort an array 5 6 INDEX 7 qsort_r 8 9 SYNOPSIS 10 #define _BSD_SOURCE 11 #include <stdlib.h> 12 void qsort_r(void *<[base]>, size_t <[nmemb]>, size_t <[size]>, 13 void *<[thunk]>, 14 int (*<[compar]>)(void*, const void *, const void *)); 15 16 #define _GNU_SOURCE 17 #include <stdlib.h> 18 void qsort_r(void *<[base]>, size_t <[nmemb]>, size_t <[size]>, 19 int (*<[compar]>)(const void *, const void *, void *), 20 void *<[thunk]>); 21 22 DESCRIPTION 23 <<qsort_r>> sorts an array (beginning at <[base]>) of <[nmemb]> objects. 24 <[size]> describes the size of each element of the array. 25 26 You must supply a pointer to a comparison function, using the argument 27 shown as <[compar]>. (This permits sorting objects of unknown 28 properties.) There are two forms of this function, in each the 29 comparison function is defined to accept three arguments, but in a 30 different order. Two are pointers to an element of the array starting at 31 <[base]>, and another being an arbitrary pointer <[thunk]>. The 32 result of <<(*<[compar]>)>> must be negative if the first argument is 33 less than the second, zero if the two arguments match, and positive if 34 the first argument is greater than the second (where ``less than'' and 35 ``greater than'' refer to whatever arbitrary ordering is appropriate). 36 37 The array is sorted in place; that is, when <<qsort_r>> returns, the 38 array elements beginning at <[base]> have been reordered. 39 40 RETURNS 41 <<qsort_r>> does not return a result. 42 43 PORTABILITY 44 <<qsort_r>>, in various forms, appears in both BSD and glibc. 45 */ 46 47 #define _GNU_SOURCE 48 #define I_AM_GNU_QSORT_R 49 #include "qsort.c" 50
