config root man

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.\"     @(#)strdup.3	8.1 (Berkeley) 6/9/93
.\" $FreeBSD: release/9.1.0/lib/libc/string/strdup.3 190798 2009-04-07 13:42:53Z trasz $
.\"
.Dd December 5, 2008
.Dt STRDUP 3
.Os
.Sh NAME
.Nm strdup ,
.Nm strndup
.Nd save a copy of a string
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.In string.h
.Ft char *
.Fn strdup "const char *str"
.Ft char *
.Fn strndup "const char *str" "size_t len"
.Sh DESCRIPTION
The
.Fn strdup
function
allocates sufficient memory for a copy
of the string
.Fa str ,
does the copy, and returns a pointer to it.
The pointer may subsequently be used as an
argument to the function
.Xr free 3 .
.Pp
If insufficient memory is available, NULL is returned and
.Va errno
is set to
.Er ENOMEM .
.Pp
The
.Fn strndup
function copies at most
.Fa len
characters from the string
.Fa str
always
.Dv NUL
terminating the copied string.
.Sh SEE ALSO
.Xr free 3 ,
.Xr malloc 3 ,
.Xr wcsdup 3
.Sh HISTORY
The
.Fn strdup
function first appeared in
.Bx 4.4 .
The
.Fn strndup
function was added in
.Fx 7.2 .