MEMORY(10.2) MEMORY(10.2)
NAME
memccpy, memchr, memcmp, memcpy, memmove, memset - memory operations
SYNOPSIS
void* memccpy(void *s1, void *s2, int c, long n)
void* memchr(void *s, int c, long n)
int memcmp(void *s1, void *s2, long n)
void* memcpy(void *s1, void *s2, long n)
void* memmove(void *s1, void *s2, long n)
void* memset(void *s, int c, long n)
DESCRIPTION
These functions operate efficiently on memory areas (arrays of bytes
bounded by a count, not terminated by a zero byte). They do not check
for the overflow of any receiving memory area.
Memccpy copies bytes from memory area s2 into s1, stopping after the
first occurrence of byte c has been copied, or after n bytes have been
copied, whichever comes first. It returns a pointer to the byte after
the copy of c in s1, or zero if c was not found in the first n bytes of
s2.
Memchr returns a pointer to the first occurrence of byte c in the first
n bytes of memory area s, or zero if c does not occur.
Memcmp compares its arguments, looking at the first n bytes 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. The
comparison is bytewise unsigned.
Memmove copies n bytes from memory area s2 to s1. It returns s1. It
is guaranteed to work if s1 and s2 overlap.
In the Inferno kernel memcpy is equivalent to memmove. (In ANSI C, by
contrast, memcpy does not account for overlapping memory regions.)
Memset sets the first n bytes in memory area s to the value of the
least significant byte of c. It returns s.
DIAGNOSTICS
If memcpy and memmove are handed negative counts, they abort.
SOURCE
/libkern/mem*.c
/libkern/mem*-objtype.s
SEE ALSO
strcat(10.2)
MEMORY(10.2)
