.\" Copyright (c) 1990 The Regents of the University of California. .\" All rights reserved. .\" .\" Redistribution and use in source and binary forms are permitted .\" provided that: (1) source distributions retain this entire copyright .\" notice and comment, and (2) distributions including binaries display .\" the following acknowledgement: ``This product includes software .\" developed by the University of California, Berkeley and its contributors'' .\" in the documentation or other materials provided with the distribution .\" and in all advertising materials mentioning features or use of this .\" software. Neither the name of the University nor the names of its .\" contributors may be used to endorse or promote products derived .\" from this software without specific prior written permission. .\" THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR .\" IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED .\" WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. .\" .\" @(#)qsort.3 6.3 (Berkeley) 5/16/90 .\" .TH QSORT 3 "May 16, 1990" .UC 4 .SH NAME qsort \- quicker sort .SH SYNOPSIS .nf .ft B #include void qsort(void *base, size_t nmemb, size_t size, int (*compar)(const void *, const void *)); .ft R .fi .SH DESCRIPTION .I Qsort is an implementation of C.A.R. Hoare's ``quicksort'' algorithm. .PP The .I qsort function sorts an array of .I nmemb objects, the initial member of which is pointed to by .IR base . The size of each object is specified by .IR size . .PP The contents of the array are sorted in ascending order according to a comparison function pointed to by .IR compar , which is called with two arguments that point to the objects being compared. .PP The comparison function must return an integer less than, equal to, or greater than zero if the first argument is considered to be respectively less than, equal to, or greater than the second. .PP If two members compare as equal, their order in the sorted array is undefined. .SH "SEE ALSO" sort(1) .SH STANDARDS .B Qsort conforms to ANSI X3.159-1989 (``ANSI C''). .SH BUGS The comparison routine may not itself call .IR qsort (3).