strdup, strndup, strdupa, strndupa — duplicate a string
#include <string.h>
char
*strdup( |
const char *s) ; |
char
*strndup( |
const char *s, |
size_t n) ; |
char
*strdupa( |
const char *s) ; |
char
*strndupa( |
const char *s, |
size_t n) ; |
Note | ||||||||||||
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|
The strdup
() function
returns a pointer to a new string which is a duplicate of the
string s
. Memory for
the new string is obtained with malloc(3), and can be freed
with free(3).
The strndup
() function is
similar, but copies at most n
bytes. If s
is longer than n
, only n
bytes are copied, and a
terminating null byte ('\0') is added.
strdupa
() and strndupa
() are similar, but use alloca(3) to allocate the
buffer. They are available only when using the GNU GCC suite,
and suffer from the same limitations described in alloca(3).
On success, the strdup
()
function returns a pointer to the duplicated string. It
returns NULL if insufficient memory was available, with
errno
set to indicate the cause
of the error.
For an explanation of the terms used in this section, see attributes(7).
Interface | Attribute | Value |
|
Thread safety | MT-Safe |
strdup
() conforms to SVr4,
4.3BSD, POSIX.1-2001. strndup
()
conforms to POSIX.1-2008. strdupa
() and strndupa
() are GNU extensions.
This page is part of release 4.07 of the Linux man-pages
project. A
description of the project, information about reporting bugs,
and the latest version of this page, can be found at
https://www.kernel.org/doc/man−pages/.
Copyright 1993 David Metcalfe (davidprism.demon.co.uk) %%%LICENSE_START(VERBATIM) Permission is granted to make and distribute verbatim copies of this manual provided the copyright notice and this permission notice are preserved on all copies. Permission is granted to copy and distribute modified versions of this manual under the conditions for verbatim copying, provided that the entire resulting derived work is distributed under the terms of a permission notice identical to this one. Since the Linux kernel and libraries are constantly changing, this manual page may be incorrect or out-of-date. The author(s) assume no responsibility for errors or omissions, or for damages resulting from the use of the information contained herein. The author(s) may not have taken the same level of care in the production of this manual, which is licensed free of charge, as they might when working professionally. Formatted or processed versions of this manual, if unaccompanied by the source, must acknowledge the copyright and authors of this work. %%%LICENSE_END References consulted: Linux libc source code Lewine's _POSIX Programmer's Guide_ (O'Reilly & Associates, 1991) 386BSD man pages Modified Sun Jul 25 10:41:34 1993 by Rik Faith (faithcs.unc.edu) Modified Wed Oct 17 01:12:26 2001 by John Levon <mozcompsoc.man.ac.uk> |