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- ' Copyright 1989 Regents of the University of California
- ' Permission to use, copy, modify, and distribute this
- ' documentation for any purpose and without fee is hereby
- ' granted, provided that this notice appears in all copies.
- ' The University of California makes no representations about
- ' the suitability of this material for any purpose. It is
- ' provided "as is" without express or implied warranty.
- '
- ' $Header: /sprite/src/lib/c/string/RCS/mem.man,v 1.2 89/02/09 10:27:17 ouster Exp $ SPRITE (Berkeley)
- '
- .so \*(]ltmac.sprite
- .HS mem lib
- .BS
- .SH NAME
- memchr, memcmp, memcpy, memset \- Operations on byte arrays
- .SH SYNOPSIS
- .nf
- \fB#include <string.h>
-
- \fBchar *
- \fBmemchr(\fIs\fB, \fIc\fB, \fIn\fB)
-
- \fBint
- \fBmemcmp(\fIs\fB, \fIs2\fB, \fIn\fB)
-
- \fBchar *
- \fBmemcpy(\fIdest\fB, \fIsource\fB, \fIn\fB)
-
- \fBchar *
- \fBmemset(\fIdest\fB, \fIc\fB, \fIn\fB)
- .SH ARGUMENTS
- .AS char source
- .AP char *s in
- Pointer to array of characters.
- .AP char *source in
- Pointer to array of characters to copy.
- .AP char *dest out
- Pointer to array of characters to modify.
- .AP int c in
- Value to search for (\fBmemchr\fR), or value to set to (\fBmemset\fR).
- .AP int n in
- Count of number of characters to test, copy, or set.
- .BE
-
- .SH DESCRIPTION
- These procedures manipulate memory as counted arrays of bytes.
- .PP
- The \fBmemchr\fR procedure searches for the first occurrence of \fIc\fR
- in the \fIn\fR bytes starting at \fIs\fR, and returns the address of the
- first such occurrence. If the value \fIc\fR is not found, then \fBNULL\fR
- is returned.
- .PP
- \fBMemcmp\fR compares two arrays of bytes, \fIs\fR and \fIs2\fR, in
- order, until a difference is found or \fIn\fR bytes have been compared.
- It returns a value greater than zero if, in the first differing byte,
- the value \fIs\fR is greater than the value in \fIs2\fR. If the value
- in \fIs\fR is less than the value in \fIs2\fR, then a value less than
- zero is returned. If the two arrays are identical in their first \fIn\fR
- bytes, then zero is returned. Signed character comparison is used.
- .PP
- \fBMemcpy\fR copies \fIn\fR bytes from \fIsource\fR to \fIdest\fR and
- returns \fIdest\fR as its result.
- .PP
- \fBMemset\fR stores the value \fIc\fR in each of the \fIn\fR bytes starting
- at \fIdest\fR, and returns \fIdest\fR as its result.
-
- .SH KEYWORDS
- characters, copy, memory, set, test
-