MEMORY(3)                            BSD                             MEMORY(3)



NAME
     memory:  memchr, memcmp, memcpy, memmove, memset - memory operations

SYNOPSIS
     #include <string.h>

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

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

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

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

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

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

     memchr returns a pointer to the first occurrence of character c in the
     first n characters of memory area s, or a NULL pointer if c does not
     occur.

     memcmp compares its arguments, looking at the first n characters only,
     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.

     memcpy copies n characters from memory area s2 to s1.  It returns s1.

     memmove copies n characters from the object pointed to by s2 into the
     object pointed to by s1.  Copying takes place as if the n characters from
     the object pointed to by s2 are first copied into a temporary array of n
     characters that does not overlap the objects pointed to by s1 and s2, and
     then the n characters from the temporary array are copied into the object
     pointed to by s1.  memmove returns the value of s1.

     memset sets the first n characters in memory area s to the value of
     character c.  It returns s.

SEE ALSO
     cc(1).

NOTES
     To be compatible with common C usage, make memchr, memcpy, and memset

     return type pointer-to-character by compiling your program with the

          -A nansi

     option (see cc(1)) and inserting the directive

          #define _CLASSIC_TYPES

     before any #include directives.

CAVEATS
     memcmp is implemented by using the most natural character comparison on
     the machine.  Thus the sign of the value returned when one of the
     characters has its high order bit set is not the same in all
     implementations and should not be relied upon.

     Character movement is performed differently in different implementations.
     Thus overlapping moves may yield surprises.