opensolaris man page for memchr

memchr(9F)						   Kernel Functions for Drivers 						memchr(9F)

NAME
       memchr, memcmp, memcpy, memmove, memset - Memory operations

SYNOPSIS
       #include <sys/ddi.h>

       void *memchr(const void *s, int c, size_t n);

       int memcmp(const void *s1, const void *s2, size_t n);

       void *memcpy(void *restrict s1, const void *restrict s2, size_t n);

       void *memmove(void *s1, const void *s2, size_t n);

       void *memset(void *s, int c, size_t n);

INTERFACE LEVEL
       Solaris DDI specific (Solaris DDI).

PARAMETERS
       dst	 Pointers to character strings.

       n	 Count of characters to be copied.

       s1, s2	 Pointers to character strings.

DESCRIPTION
       These  functions  operate  as efficiently as possible on memory areas (arrays of bytes bounded by a count, not terminated by a null charac-
       ter). They do not check for the overflow of any receiving memory area.

       The memchr() function returns a pointer to the first occurrence of c (converted to an unsigned char) in the first n bytes (each interpreted
       as an unsigned char) of memory area s, or a null pointer if c does not occur.

       The  memcmp()  function compares its arguments, looking at the first n bytes (each interpreted as an unsigned char), and returns an integer
       less than, equal to, or greater than 0, according as s1 is lexicographically less than, equal to, or greater  than  s2  when  taken  to	be
       unsigned characters.

       The  memcpy()  function	copies	n bytes from memory area s2 to s1. It returns s1. If copying takes place between objects that overlap, the
       behavior is undefined.

       The memmove() function copies n bytes from memory area s2 to memory area s1. Copying between objects that  overlap  will  take  place  cor-
       rectly. It returns s1.

       The memset() function sets the first n bytes in memory area s to the value of c (converted to an unsigned char). It returns s.

USAGE
       Using memcpy() might be faster than using memmove() if the application knows that the objects being copied do not overlap.

CONTEXT
       These functions can be called from user, interrupt, or kernel context.

SEE ALSO
       bcopy(9F), ddi_copyin(9F), strcpy(9F)

       Writing Device Drivers

SunOS 5.11							    16 Jan 2006 							memchr(9F)