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
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MEMORY(10.2) MEMORY(10.2)
If memcpy and memmove are handed negative counts, they
abort.
SOURCE
/libkern/mem*.c
/libkern/mem*-objtype.s
SEE ALSO
strcat(10.2)
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