bsearch(3) [ultrix man page]

```bsearch(3)						     Library Functions Manual							bsearch(3)

Name
bsearch - binary search a sorted table

Syntax
#include <stdlib.h>

void *bsearch (key, base, nel, sizeof (*key), compar)
void *key, *base;
size_t nel;
int (*compar)( );

Description
The subroutine is a binary search routine generalized from Knuth (6.2.1) Algorithm B.  It returns a pointer into a table indicating where a
datum may be found.  The table must be previously sorted in increasing order according to a provided comparison function.  The  key  points
to the datum to be sought in the table.	The base points to the element at the base of the table.  The nel is the number of elements in the
table.  The compar is the name of the comparison function, which is called with two arguments that point to the	elements  being  compared.
The  function  must return an integer less than, equal to, or greater than zero according to whether the first argument is to be considered
less than, equal to, or greater than the second.

Diagnostics
A NULL pointer is returned if the key cannot be found in the table.

Notes
The pointers to the key and the element at the base of the table should be of type pointer-to-element, and cast to type	pointer-to-charac-
ter.

The  comparison	function  need	not compare every byte, so arbitrary data may be contained in the elements in addition to the values being
compared.

Although declared as type pointer-to-character, the value returned should be cast into type pointer-to-element.

hsearch(3), lsearch(3), qsort(3), tsearch(3)

bsearch(3)```

Check Out this Related Man Page

```lsearch(3)						     Library Functions Manual							lsearch(3)

Name
lsearch, lfind - linear search and update

Syntax
#include <search.h>
#include <sys/types.h>

void *lsearch (key, base, nelp, width, compar)
void *key;
void *base;
size_t *nelp;
size_t width;
int (*compar)( );

void *lfind (key, base, nelp, width, compar)
void *key;
void *base;
size_t *nelp;
size_t width;
int (*compar)( );

Description
The  subroutine	is a linear search routine generalized from Knuth (6.1) Algorithm S.  It returns a pointer into a table indicating where a
datum may be found.  If the datum does not occur, it is added at the end of the table.  The key points to the datum to be sought in the ta-
ble.   The  base  points to the first element in the table.  The nelp points to an integer containing the current number of elements in the
table.  The width is the size of an element in bytes.  The integer is incremented if the datum is added to the table.  The  compar  is  the
name  of  the comparison function which the user must supply (strcmp, for example).  It is called with two arguments that point to the ele-
ments being compared.  The function must return zero if the elements are equal and non-zero otherwise.

The subroutine is the same as lsearch except that if the datum is not found, it is not added to the table.   Instead,  a  NULL  pointer	is
returned.  The pointers to the key and the element at the base of the table should be of type pointer-to-element, and cast to type pointer-
to-character.

The comparison function need not compare every byte, so arbitrary data may be contained in the elements in addition  to	the  values  being
compared.

Although declared as type pointer-to-character, the value returned should be cast into type pointer-to-element.

Restrictions
Undefined results can occur if there is not enough room in the table to add a new item.

Return Values
If the searched for datum is found, both and return a pointer to it.  Otherwise, returns NULL and returns a pointer to the newly added ele-
ment.

bsearch(3), hsearch(3), tsearch(3)

lsearch(3)```
Man Page