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+.\"     $OpenBSD: strncpy.3,v 1.1 2013/12/19 20:52:37 millert Exp $
+.\"
+.\" Copyright (c) 1990, 1991 The Regents of the University of California.
+.\" All rights reserved.
+.\"
+.\" This code is derived from software contributed to Berkeley by
+.\" Chris Torek and the American National Standards Committee X3,
+.\" on Information Processing Systems.
+.\"
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\" 1. Redistributions of source code must retain the above copyright
+.\"    notice, this list of conditions and the following disclaimer.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\"    notice, this list of conditions and the following disclaimer in the
+.\"    documentation and/or other materials provided with the distribution.
+.\" 3. Neither the name of the University nor the names of its contributors
+.\"    may be used to endorse or promote products derived from this software
+.\"    without specific prior written permission.
+.\"
+.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+.\" SUCH DAMAGE.
+.\"
+.Dd $Mdocdate: December 19 2013 $
+.Dt STRNCPY 3
+.Os
+.Sh NAME
+.Nm strncpy
+.Nd copy part of a string to another
+.Sh SYNOPSIS
+.In string.h
+.Ft char *
+.Fn strncpy "char *dst" "const char *src" "size_t len"
+.Sh DESCRIPTION
+The
+.Fn strncpy
+function copies not more than
+.Fa len
+characters from the string
+.Fa src
+to
+.Fa dst .
+If
+.Fa src
+is less than
+.Fa len
+characters long,
+it appends
+.Ql \e0
+characters for the rest of
+.Fa len .
+If the length of
+.Fa src
+is greater than or equal to
+.Fa len ,
+.Fa dst
+will
+.Em not
+be NUL-terminated.
+.Pp
+If the
+.Fa src
+and
+.Fa dst
+strings overlap, the behavior is undefined.
+.Sh RETURN VALUES
+The
+.Fn strncpy
+function returns
+.Fa dst .
+.Sh EXAMPLES
+The following sets
+.Va chararray
+to
+.Dq abc\e0\e0\e0 :
+.Bd -literal -offset indent
+(void)strncpy(chararray, "abc", 6);
+.Ed
+.Pp
+The following sets
+.Va chararray
+to
+.Dq abcdef
+and does
+.Em not
+NUL terminate
+.Va chararray
+because the length of the source string is greater than or equal to the
+length parameter.
+.Fn strncpy
+.Em only
+NUL terminates the destination string when the length of the source
+string is less than the length parameter.
+.Bd -literal -offset indent
+(void)strncpy(chararray, "abcdefgh", 6);
+.Ed
+.Pp
+The following copies as many characters from
+.Va input
+to
+.Va buf
+as will fit and NUL terminates the result.
+Because
+.Fn strncpy
+does
+.Em not
+guarantee to NUL terminate the string itself, it must be done by hand.
+.Bd -literal -offset indent
+char buf[BUFSIZ];
+
+(void)strncpy(buf, input, sizeof(buf) - 1);
+buf[sizeof(buf) - 1] = '\e0';
+.Ed
+.Pp
+Note that
+.Xr strlcpy 3
+is a better choice for this kind of operation.
+The equivalent using
+.Xr strlcpy 3
+is simply:
+.Bd -literal -offset indent
+(void)strlcpy(buf, input, sizeof(buf));
+.Ed
+.Sh SEE ALSO
+.Xr bcopy 3 ,
+.Xr memccpy 3 ,
+.Xr memcpy 3 ,
+.Xr memmove 3 ,
+.Xr strcat 3 ,
+.Xr strlcpy 3 ,
+.Xr strncat 3 ,
+.Xr wcscpy 3 ,
+.Xr wcslcpy 3
+.Sh STANDARDS
+The
+.Fn strncpy
+function conforms to
+.St -ansiC .
+.Sh HISTORY
+The
+.Fn strncpy
+function first appeared in
+.At v7 .