lsearch(3) [netbsd man page]

LSEARCH(3)						   BSD Library Functions Manual 						LSEARCH(3)

NAME

     lsearch, lfind -- linear searching routines

LIBRARY

     Standard C Library (libc, -lc)

SYNOPSIS

     #include <search.h>

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

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

DESCRIPTION

     The functions lsearch(), and lfind() provide basic linear searching functionality.

     base is the pointer to the beginning of an array.	The argument nelp is the current number of elements in the array, where each element is
     width bytes long.	The compar argument points to a function which compares its two arguments and returns zero if they are matching, and non-
     zero otherwise.

     The lsearch() and lfind() functions return a pointer into the array referenced by base where key is located.  If key does not exist, lfind()
     will return a null pointer and lsearch() will add it to the array.  When an element is added to the array by lsearch() the location refer-
     enced by the argument nelp is incremented by one.

SEE ALSO

     bsearch(3), db(3)

STANDARDS

     The lsearch() and lfind() functions conform to IEEE Std 1003.1-2001 (``POSIX.1'').

BSD
								   July 6, 2005 							       BSD

LSEARCH(3)						   BSD Library Functions Manual 						LSEARCH(3)

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 (*compar)(const void *, const void *));

     void *
     lfind(const void *key, const void *base, size_t *nelp, size_t width, int (*compar)(const 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 com-
     parison 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 input0);
		     return (EXIT_FAILURE);
	     }

	     element = lfind(&key, array, &array_size, element_size,
		 element_compare);

	     if (element != NULL)
		     printf("Element found: %d0, *(int *)element);
	     else
		     printf("Element not found0);

	     return (EXIT_SUCCESS);
     }

SEE ALSO

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

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'').

BSD
								  April 21, 2013							       BSD