The use of Qsort in Linux

Function prototypes

#include <stdlib.h>

void Qsort (void *base, size_t nmemb, size_t size, int (*compar) (const void *, const void *));

Parameter description:

Base: The starting address of the sorted array

NMEMB: The number of elements to sort

Size: A single element

Compar: User-defined method for comparing two element sizes.

Int (*compar) (const void *P1, const void *P2) function description

Ascending: Returns a positive number when P1 is greater than P2, returns 0 for equality, less than return negative

Descending: Returns a negative number when P1 is greater than P2, returns 0 for equality, less than the return positive number

eg

#include <stdio.h> #include <stdlib.h> #include <string.h>static intcmp (const void *P1, const void *P2) {return * (int*) P1-* (int*) P2;}  Intmain (int argc, char *argv[]) {int j;int s[10]={1,3,5,7,9,2,4,6,8,0};qsort (&s[0], ten, sizeof (S[0]), CMP); for (j = 0; J < 10; J + +) printf ("%d\n", S[j]); exit (exit_success);}

Run results

The use of Qsort in Linux