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<title>memory(3) - Plan 9 from User Space</title>
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<tr><td width=20><td><b>MEMORY(3)</b><td align=right><b>MEMORY(3)</b>
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<p><font size=+1><b>NAME </b></font><br>
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memccpy, memchr, memcmp, memcpy, memmove, memset – memory operations<br>
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<p><font size=+1><b>SYNOPSIS </b></font><br>
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<tt><font size=+1>#include <u.h><br>
#include <libc.h>
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<tt><font size=+1>void* memccpy(void *s1, void *s2, int c, long n)
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<tt><font size=+1>void* memchr(void *s, int c, long n)
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<tt><font size=+1>int memcmp(void *s1, void *s2, long n)
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<tt><font size=+1>void* memcpy(void *s1, void *s2, long n)
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<tt><font size=+1>void* memmove(void *s1, void *s2, long n)
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<tt><font size=+1>void* memset(void *s, int c, long n)<br>
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<p><font size=+1><b>DESCRIPTION </b></font><br>
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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.
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<i>Memccpy</i> copies bytes from memory area <i>s2</i> into <i>s1</i>, stopping after
the first occurrence of byte <i>c</i> has been copied, or after <i>n</i> bytes
have been copied, whichever comes first. It returns a pointer
to the byte after the copy of <i>c</i> in <i>s1</i>, or zero if <i>c</i> was not found
in the first <i>n</i> bytes of <i>s2</i>.
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<i>Memchr</i> returns a pointer to the first occurrence of byte <i>c</i> in
the first <i>n</i> bytes of memory area <i>s,</i> or zero if <i>c</i> does not occur.
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<i>Memcmp</i> compares its arguments, looking at the first <i>n</i> bytes only,
and returns an integer less than, equal to, or greater than 0,
according as <i>s1</i> is lexicographically less than, equal to, or greater
than <i>s2</i>. The comparison is bytewise unsigned.
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<i>Memcpy</i> copies <i>n</i> bytes from memory area <i>s2</i> to <i>s1</i>. It returns <i>s1</i>.
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<i>Memmove</i> works like <i>memcpy</i>, except that it is guaranteed to work
if <i>s1</i> and <i>s2</i> overlap.
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<i>Memset</i> sets the first <i>n</i> bytes in memory area <i>s</i> to the value of
byte <i>c</i>. It returns <i>s</i>.<br>
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<p><font size=+1><b>SOURCE </b></font><br>
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All these routines have portable C implementations in <tt><font size=+1>/usr/local/plan9/src/lib9</font></tt>.<br>
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<p><font size=+1><b>SEE ALSO </b></font><br>
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<a href="../man3/strcat.html"><i>strcat</i>(3)</a><br>
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<p><font size=+1><b>BUGS </b></font><br>
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ANSI C does not require <i>memcpy</i> to handle overlapping source and
destination; on Plan 9, it does, so <i>memmove</i> and <i>memcpy</i> behave
identically.
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If <i>memcpy</i> and <i>memmove</i> are handed a negative count, they abort.<br>
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