\" Copyright (c) 1990, 1991, 1993
\" The Regents of the University of California. All rights reserved.
\"
\" 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.
\"
\" from: @(#)strdup.3 8.1 (Berkeley) 6/9/93
\" $NetBSD: strdup.3,v 1.19 2024/12/09 12:09:02 nros Exp $
\"
Dd December 9, 2024
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,
Dv NULL
is returned.
Pp
The
Fn strndup
function copies at most
Fa len
characters from the string
Fa str
always
Dv NUL
terminating the copied string.
Sh EXAMPLES
The following will point
Va p
to an allocated area of memory containing the nul-terminated string
Qq foobar :
Bd -literal -offset indent
char *p;
if ((p = strdup("foobar")) == NULL) {
fprintf(stderr, "Out of memory.\en");
exit(1);
}
Ed
Sh ERRORS
The
Fn strdup
function may fail and set the external variable
Va errno
for any of the errors specified for the library function
Xr malloc 3 .
Sh SEE ALSO
Xr free 3 ,
Xr malloc 3 ,
Xr strcpy 3 ,
Xr strlen 3
Sh STANDARDS
The
Fn strdup
function conforms to
St -p1003.1-2001 .
The
Fn strdup
and
Fn strndup
functions conform to
St -isoC-2023 .
Sh HISTORY
The
Fn strdup
function first appeared in
Bx 4.4 .
The
Fn strndup
function was added in
Nx 4.0 .
