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Date:      Wed, 17 Jul 2019 19:29:55 +0000 (UTC)
From:      Konstantin Belousov <kib@FreeBSD.org>
To:        src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org
Subject:   svn commit: r350091 - head/lib/libc/stdlib
Message-ID:  <201907171929.x6HJTtJ2095196@repo.freebsd.org>

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Author: kib
Date: Wed Jul 17 19:29:55 2019
New Revision: 350091
URL: https://svnweb.freebsd.org/changeset/base/350091

Log:
  bsearch.3: Improve the example.
  
  Submitted by:	fernape
  MFC after:	1 week
  Differential revision:	https://reviews.freebsd.org/D19902

Modified:
  head/lib/libc/stdlib/bsearch.3

Modified: head/lib/libc/stdlib/bsearch.3
==============================================================================
--- head/lib/libc/stdlib/bsearch.3	Wed Jul 17 19:11:24 2019	(r350090)
+++ head/lib/libc/stdlib/bsearch.3	Wed Jul 17 19:29:55 2019	(r350091)
@@ -32,7 +32,7 @@
 .\"     @(#)bsearch.3	8.3 (Berkeley) 4/19/94
 .\" $FreeBSD$
 .\"
-.Dd May 15, 2019
+.Dd July 17, 2019
 .Dt BSEARCH 3
 .Os
 .Sh NAME
@@ -93,26 +93,29 @@ A sample program that searches people by age in a sort
 #include <string.h>
 
 struct person {
-	char name[5];
-	int age;
+	const char 	*name;
+	int 		age;
 };
 
-int
-compare(const void *key, const void *array_member)
+static int
+compare(const void *a, const void *b)
 {
-	int age = (intptr_t) key;
-	struct person person = *(struct person *) array_member;
+	const int *age;
+	const struct person *person;
 
-	return (age - person.age);
+	age = a;
+	person = b;
+
+	return (*age - person->age);
 }
 
 int
-main()
+main(void)
 {
 	struct person *friend;
-
+	int age;
 	/* Sorted array */
-	struct person friends[6] = {
+	const struct person friends[] = {
 		{ "paul", 22 },
 		{ "anne", 25 },
 		{ "fred", 25 },
@@ -120,22 +123,28 @@ main()
 		{ "mark", 35 },
 		{ "bill", 50 }
 	};
+	const size_t len = sizeof(friends) / sizeof(friends[0]);
 
-	size_t array_size = sizeof(friends) / sizeof(struct person);
-
-	friend = bsearch((void *)22, &friends, array_size, sizeof(struct person), compare);
+	age = 22;
+	friend = bsearch(&age, friends, len, sizeof(friends[0]), compare);
 	assert(strcmp(friend->name, "paul") == 0);
 	printf("name: %s\enage: %d\en", friend->name, friend->age);
 
-	friend = bsearch((void *)25, &friends, array_size, sizeof(struct person), compare);
-	assert(strcmp(friend->name, "fred") == 0 || strcmp(friend->name, "anne") == 0);
+	age = 25;
+	friend = bsearch(&age, friends, len, sizeof(friends[0]), compare);
+
+	/*
+	 * For multiple elements with the same key, it is implementation
+	 * defined which will be returned
+	 */
+	assert(strcmp(friend->name, "fred") == 0 ||
+	    strcmp(friend->name, "anne") == 0);
 	printf("name: %s\enage: %d\en", friend->name, friend->age);
 
-	friend = bsearch((void *)30, &friends, array_size, sizeof(struct person), compare);
+	age = 30;
+	friend = bsearch(&age, friends, len, sizeof(friends[0]), compare);
 	assert(friend == NULL);
 	printf("friend aged 30 not found\en");
-
-	return (EXIT_SUCCESS);
 }
 .Ed
 .Sh SEE ALSO



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