# qsort(3) [ultrix man page]

```qsort(3)						     Library Functions Manual							  qsort(3)

Name
qsort - quicker sort

Syntax
#include <stdlib.h>

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

Description
The  subroutine is an implementation of the quicker-sort algorithm.  The first argument is a pointer to the base of the data; the second is
the number of elements; the third is the width of an element in bytes; the last is the name of the comparison routine to be called with two
arguments  which  are  pointers	to the elements being compared.  The routine must return an integer less than, equal to, or greater than 0
according as the first argument is to be considered less than, equal to, or greater than the second.

sort(1)

qsort(3)```

## Check Out this Related Man Page

```bsearch(3)						     Library Functions Manual							bsearch(3)

Name
bsearch - binary search a sorted table

Syntax
#include <stdlib.h>

void *bsearch (key, base, nel, sizeof (*key), compar)
void *key, *base;
size_t nel;
int (*compar)( );

Description
The subroutine is a binary search routine generalized from Knuth (6.2.1) Algorithm B.  It returns a pointer into a table indicating where a
datum may be found.  The table must be previously sorted in increasing order according to a provided comparison function.  The  key  points
to the datum to be sought in the table.	The base points to the element at the base of the table.  The nel is the number of elements in the
table.  The compar is the name of the comparison function, which is called with two arguments that point to the	elements  being  compared.
The  function  must return an integer less than, equal to, or greater than zero according to whether the first argument is to be considered
less than, equal to, or greater than the second.

Diagnostics
A NULL pointer is returned if the key cannot be found in the table.

Notes
The pointers to the key and the element at the base of the table should be of type pointer-to-element, and cast to type	pointer-to-charac-
ter.

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

Although declared as type pointer-to-character, the value returned should be cast into type pointer-to-element.