qsort

Purpose

     Sorts a table of data in place.

Library

     Standard C Library (libc.a)

Syntax

     void qsort ((char *) base, nel, sizeof (*base), compar)
     unsigned int nel;
     int (*compar) ( );

Description

     The qsort subroutine sorts a  table of data in place.  It
     uses the "quicker-sort" algorithm.

     The base parameter  points to the element at  the base of
     the table.  The  nel parameter is the  number of elements
     in the  table.  The compar  parameter is the name  of the
     comparison function.  (See "alphasort"  for one such com-
     parison function.)

     The comparison  function must compare its  parameters and
     return a value as follows:

     o   If the first parameter is less than the second param-
         eter, compar must return a value less than 0.
     o   If the first parameter is  equal to the second param-
         eter, compar must return 0.
     o   If  the first  parameter is  greater than  the second
         parameter, compar must return a value greater than 0.

     The comparison  function need not compare  every byte, so
     arbitrary data can be contained  in the elements in addi-
     tion to the values being compared.

     Note:  The order in the  output of two items that compare
     equal is unpredictable.

     The pointer  to the base of  the table should be  of type
     pointer-to-element,   and   cast  to   type   pointer-to-
     character.

Related Information

     In this book:   "alphasort," "bsearch," "lsearch, lfind,"
     and "string."

     The sort command in  AIX Operating System Commands Refer-
     ence.