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qsort(3C)		 Standard C Library Functions		     qsort(3C)

NAME
       qsort - quick sort

SYNOPSIS
       #include	<stdlib.h>

       void  qsort(void	 *base,	 size_t	nel, size_t width, int (*compar)(const
       void *, const void *));

DESCRIPTION
       The qsort() function is an implementation of the	quick-sort  algorithm.
       It sorts	a table	of data	in place. The contents of the table are	sorted
       in ascending order according to the  user-supplied comparison function.

       The base	argument points	to the element at the base of the table.   The
       nel  argument  is the number of elements	in the table.  The width argu-
       ment specifies the size of each element in bytes.  The compar  argument
       is  the name of the comparison function,	which is called	with two argu-
       ments that point	to the elements	being compared.

       The function must return	an integer less	than,  equal  to,  or  greater
       than  zero  to  indicate	if the first argument is to be considered less
       than, equal to, or greater than the second argument.

       The contents of the table are sorted in ascending  order	 according  to
       the user	supplied comparison function.

USAGE
       The  qsort()  function  safely  allows  concurrent  access by  multiple
       threads to disjoint data, such as overlapping subtrees or tables.

EXAMPLES
       Example 1: Program sorts.

       The following program sorts a simple array:

       #include	<stdlib.h>
       #include	<stdio.h>

       static int
       intcompare(const	void *p1, const	void *p2)
       {
	   int i = *((int *)p1);
	   int j = *((int *)p2);

	   if (i > j)
	       return (1);
	   if (i < j)
	       return (-1);
	   return (0);
       }

       int
       main()
       {
	   int i;
	   int a[10] = { 9, 8, 7, 6, 5,	4, 3, 2, 1, 0 };
	   size_t nelems = sizeof (a) /	sizeof (int);

	   qsort((void *)a, nelems, sizeof (int), intcompare);

	   for (i = 0; i < nelems; i++)	{
	       (void) printf("%d ", a[i]);
	   }

	   (void) printf("\n");
	   return (0);
       }

ATTRIBUTES
       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE	TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Interface Stability	     |Standard			   |
       +-----------------------------+-----------------------------+
       |MT-Level		     |MT-Safe			   |
       +-----------------------------+-----------------------------+

SEE ALSO
       sort(1),	bsearch(3C),  lsearch(3C),  string(3C),	 attributes(5),	 stan-
       dards(5)

NOTES
       The  comparison function	need not compare every byte, so	arbitrary data
       may be contained	in the elements	in addition to the values  being  com-
       pared.

       The  relative order in the output of two	items that compare as equal is
       unpredictable.

SunOS 5.10			  6 Dec	2004			     qsort(3C)

NAME | SYNOPSIS | DESCRIPTION | USAGE | EXAMPLES | ATTRIBUTES | SEE ALSO | NOTES

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