Add small EXAMPLE section to bsearch.3.
Submitted by: fernape (via Phabricator) Reviewed by: bcr, jilles, dab Approved by: bcr (man pages), jilles (src) MFC after: 3 days Differential Revision: https://reviews.freebsd.org/D19902
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svn2git
2020-12-20 02:59:44 +00:00
svn path=/head/; revision=347617
@ -32,7 +32,7 @@
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.\" @(#)bsearch.3 8.3 (Berkeley) 4/19/94
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.\" $FreeBSD$
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.\"
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.Dd February 22, 2013
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.Dd May 15, 2019
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.Dt BSEARCH 3
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.Os
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.Sh NAME
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@ -83,6 +83,61 @@ The
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function returns a pointer to a matching member of the array, or a null
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pointer if no match is found.
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If two members compare as equal, which member is matched is unspecified.
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.Sh EXAMPLES
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A sample program that searches people by age in a sorted array:
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.Bd -literal
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#include <assert.h>
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#include <stdint.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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struct person {
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char name[5];
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int age;
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};
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int
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compare(const void *key, const void *array_member)
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{
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int age = (intptr_t) key;
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struct person person = *(struct person *) array_member;
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return (age - person.age);
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}
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int
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main()
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{
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struct person *friend;
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/* Sorted array */
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struct person friends[6] = {
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{ "paul", 22 },
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{ "anne", 25 },
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{ "fred", 25 },
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{ "mary", 27 },
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{ "mark", 35 },
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{ "bill", 50 }
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};
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size_t array_size = sizeof(friends) / sizeof(struct person);
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friend = bsearch((void *)22, &friends, array_size, sizeof(struct person), compare);
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assert(strcmp(friend->name, "paul") == 0);
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printf("name: %s\enage: %d\en", friend->name, friend->age);
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friend = bsearch((void *)25, &friends, array_size, sizeof(struct person), compare);
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assert(strcmp(friend->name, "fred") == 0 || strcmp(friend->name, "anne") == 0);
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printf("name: %s\enage: %d\en", friend->name, friend->age);
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friend = bsearch((void *)30, &friends, array_size, sizeof(struct person), compare);
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assert(friend == NULL);
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printf("friend aged 30 not found\en");
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return (EXIT_SUCCESS);
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}
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.Ed
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.Sh SEE ALSO
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.Xr db 3 ,
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.Xr lsearch 3 ,
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