---
name: "lfind"
section: "3"
platform: "freebsd"
package: "base"
version: "16.0-CURRENT-20261027-61c70dc16a79"
release: "FreeBSD 16.0-CURRENT (2026-10-27)"
platforms: ["linux", "freebsd"]
url: "https://new.carta.tech/lfind"
---

# lfind(3)

linear search and append

## NAME

**lsearch**, **lfind** – linear search and append

## LIBRARY

Standard C Library (libc, -lc)

## SYNOPSIS

**#include \<search.h\>**

*void \**\

**lsearch**(*const void \*key*, *void \*base*, *size\_t \*nelp*, *size\_t width*, *int \*comparconst void \*, const void \**);

*void \**\

**lfind**(*const void \*key*, *const void \*base*, *size\_t \*nelp*, *size\_t width*, *int \*comparconst void \*, const void \**);

## DESCRIPTION

The **lsearch**() and **lfind**() functions walk linearly through an array and compare each element with the one to be sought using a supplied comparison function.

The *key* argument points to an element that matches the one that is searched. The array's address in memory is denoted by the *base* argument. The width of one element (i.e., the size as returned by **sizeof**()) is passed as the *width* argument. The number of valid elements contained in the array (not the number of elements the array has space reserved for) is given in the integer pointed to by *nelp*. The *compar* argument points to a function which compares its two arguments and returns zero if they are matching, and non-zero otherwise.

If no matching element was found in the array, **lsearch**() copies *key* into the position after the last element and increments the integer pointed to by *nelp*.

## RETURN VALUES

The **lsearch**() and **lfind**() functions return a pointer to the first element found. If no element was found, **lsearch**() returns a pointer to the newly added element, whereas **lfind**() returns NULL. Both functions return NULL if an error occurs.

## EXAMPLES

```
#include <search.h>
#include <stdio.h>
#include <stdlib.h>
static int
element_compare(const void *p1, const void *p2)
{
	int left = *(const int *)p1;
	int right = *(const int *)p2;
	return (left - right);
}
int
main(int argc, char **argv)
{
	const int array[10] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
	size_t element_size = sizeof(array[0]);
	size_t array_size = sizeof(array) / element_size;
	int key;
	void *element;
	printf("Enter a number: ");
	if (scanf("%d", &key) != 1) {
		printf("Bad input\n");
		return (EXIT_FAILURE);
	}
	element = lfind(&key, array, &array_size, element_size,
	    element_compare);
	if (element != NULL)
		printf("Element found: %d\n", *(int *)element);
	else
		printf("Element not found\n");
	return (EXIT_SUCCESS);
}
```

## SEE ALSO

[bsearch(3)](/bsearch/3.md), [hsearch(3)](/hsearch/3.md), [tsearch(3)](/tsearch/3.md)

## STANDARDS

The **lsearch**() and **lfind**() functions conform to IEEE Std 1003.1-2001 (“POSIX.1”).

## HISTORY

The **lsearch**() and **lfind**() functions appeared in 4.2BSD. In FreeBSD 5.0, they reappeared conforming to IEEE Std 1003.1-2001 (“POSIX.1”).