Date: Sat, 16 Feb 2013 17:50:30 GMT From: Fernando <fapesteguia@opensistemas.com> To: freebsd-gnats-submit@FreeBSD.org Subject: docs/176197: [PATCH] Add example to qsort.3 Message-ID: <201302161750.r1GHoUDv018083@red.freebsd.org> Resent-Message-ID: <201302161800.r1GI00Nb029853@freefall.freebsd.org>
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>Number: 176197
>Category: docs
>Synopsis: [PATCH] Add example to qsort.3
>Confidential: no
>Severity: non-critical
>Priority: low
>Responsible: freebsd-doc
>State: open
>Quarter:
>Keywords:
>Date-Required:
>Class: change-request
>Submitter-Id: current-users
>Arrival-Date: Sat Feb 16 18:00:00 UTC 2013
>Closed-Date:
>Last-Modified:
>Originator: Fernando
>Release: 9.0-RELEASE
>Organization:
Open Sistemas
>Environment:
FreeBSD hammer 9.0-RELEASE FreeBSD 9.0-RELEASE #0: Tue Jan 3 07:46:30 UTC 2012 root@farrell.cse.buffalo.edu:/usr/obj/usr/src/sys/GENERIC amd64
>Description:
qsort(3) lacks an example in the man page. If we want to have the best documentation available, we need examples in some man pages.
>How-To-Repeat:
man qsort
It doesn't show an example of use
>Fix:
Apply the attached patch.
Patch attached with submission follows:
--- lib/libc/stdlib/qsort.3 2012-01-03 04:26:05.000000000 +0100
+++ /home/fernape/Programming/FreeBSD/qsort_man/qsort.3 2013-02-16 18:42:44.000000000 +0100
@@ -211,6 +211,52 @@
did not permit the comparison routine itself to call
.Fn qsort 3 .
This is no longer true.
+.Sh EXAMPLES
+Sort an array of integers.
+.Bd -literal
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+/*
+ * Custom comparison function
+ */
+static int
+str_compare(const void *p1, const void *p2)
+{
+
+ /* Cast and dereference */
+ if (*(int *)p1 < *(int *)p2)
+ return (-1);
+
+ if (*(int *)p1 > *(int *)p2)
+ return (1);
+
+ return (0);
+
+}
+
+/*
+ * Sort an array of integers
+ */
+int
+main(int argc, char **argv)
+{
+ int i;
+ int int_array[] = {4, 5, 9, 3, 1, 7, 2, 8, 6};
+ const int array_size = sizeof(int_array) / sizeof(int);
+
+ /* Sort array */
+ qsort(&int_array, array_size, sizeof(int), str_compare);
+
+ /* Print out sorted array */
+ for (i = 0; i < array_size; i++) {
+ printf("%d\n", int_array[i]);
+ }
+
+ exit(EXIT_SUCCESS);
+}
+.Ed
.Sh ERRORS
The
.Fn heapsort
>Release-Note:
>Audit-Trail:
>Unformatted:
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