2004-11-03 13:51:07 +00:00
|
|
|
.\" Copyright 1993 David Metcalfe (david@prism.demon.co.uk)
|
|
|
|
.\"
|
|
|
|
.\" 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.
|
2007-04-12 22:42:49 +00:00
|
|
|
.\"
|
2004-11-03 13:51:07 +00:00
|
|
|
.\" 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.\" manual page may be incorrect or out-of-date.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.
|
2007-04-12 22:42:49 +00:00
|
|
|
.\"
|
2004-11-03 13:51:07 +00:00
|
|
|
.\" Formatted or processed versions of this manual, if unaccompanied by
|
|
|
|
.\" the source, must acknowledge the copyright and authors of this work.
|
|
|
|
.\"
|
|
|
|
.\" 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 (faith@cs.unc.edu)
|
|
|
|
.\" Modified Wed Oct 17 01:12:26 2001 by John Levon <moz@compsoc.man.ac.uk>
|
2007-07-08 12:11:40 +00:00
|
|
|
.TH STRDUP 3 2007-07-26 "GNU" "Linux Programmer's Manual"
|
2004-11-03 13:51:07 +00:00
|
|
|
.SH NAME
|
|
|
|
strdup, strndup, strdupa, strndupa \- duplicate a string
|
|
|
|
.SH SYNOPSIS
|
|
|
|
.nf
|
|
|
|
.B #include <string.h>
|
|
|
|
.sp
|
|
|
|
.BI "char *strdup(const char *" s );
|
|
|
|
.sp
|
|
|
|
.BI "char *strndup(const char *" s ", size_t " n );
|
|
|
|
.br
|
|
|
|
.BI "char *strdupa(const char *" s );
|
|
|
|
.br
|
|
|
|
.BI "char *strndupa(const char *" s ", size_t " n );
|
|
|
|
.fi
|
2007-07-08 12:11:40 +00:00
|
|
|
.sp
|
|
|
|
.in -4n
|
|
|
|
Feature Test Macro Requirements for glibc (see
|
|
|
|
.BR feature_test_macros (7)):
|
|
|
|
.in
|
|
|
|
.sp
|
|
|
|
.BR strdup ():
|
|
|
|
_SVID_SOURCE || _BSD_SOURCE || _XOPEN_SOURCE\ >=\ 500
|
|
|
|
.br
|
|
|
|
.BR strndup (),
|
|
|
|
.BR strdupa (),
|
|
|
|
.BR strndupa ():
|
|
|
|
_GNU_SOURCE
|
2004-11-03 13:51:07 +00:00
|
|
|
.SH DESCRIPTION
|
2007-05-12 09:06:04 +00:00
|
|
|
The
|
|
|
|
.BR strdup ()
|
|
|
|
function returns a pointer to a new string which
|
2007-04-24 16:44:51 +00:00
|
|
|
is a duplicate of the string \fIs\fP.
|
|
|
|
Memory for the new string is
|
2007-05-12 09:06:04 +00:00
|
|
|
obtained with
|
|
|
|
.BR malloc (3),
|
|
|
|
and can be freed with
|
|
|
|
.BR free (3).
|
2004-11-03 13:51:07 +00:00
|
|
|
|
2007-05-12 09:06:04 +00:00
|
|
|
The
|
|
|
|
.BR strndup ()
|
|
|
|
function is similar, but only copies at most
|
2007-04-12 22:42:49 +00:00
|
|
|
\fIn\fP characters.
|
|
|
|
If \fIs\fP is longer than \fIn\fP, only \fIn\fP
|
2008-06-09 15:49:35 +00:00
|
|
|
characters are copied, and a terminating null byte (\(aq\\0\(aq) is added.
|
2004-11-03 13:51:07 +00:00
|
|
|
|
2007-05-12 09:06:04 +00:00
|
|
|
.BR strdupa ()
|
|
|
|
and
|
|
|
|
.BR strndupa ()
|
|
|
|
are similar, but use
|
|
|
|
.BR alloca (3)
|
2007-04-12 22:42:49 +00:00
|
|
|
to allocate the buffer.
|
|
|
|
They are only available when using the GNU
|
2007-05-12 09:06:04 +00:00
|
|
|
GCC suite, and suffer from the same limitations described in
|
|
|
|
.BR alloca (3).
|
2004-11-03 13:51:07 +00:00
|
|
|
.SH "RETURN VALUE"
|
2007-05-12 09:06:04 +00:00
|
|
|
The
|
|
|
|
.BR strdup ()
|
|
|
|
function returns a pointer to the duplicated
|
2004-11-03 13:51:07 +00:00
|
|
|
string, or NULL if insufficient memory was available.
|
|
|
|
.SH ERRORS
|
|
|
|
.TP
|
|
|
|
.B ENOMEM
|
|
|
|
Insufficient memory available to allocate duplicate string.
|
|
|
|
.SH "CONFORMING TO"
|
2005-07-18 15:05:56 +00:00
|
|
|
.\" 4.3BSD-Reno, not (first) 4.3BSD.
|
2006-08-03 13:57:30 +00:00
|
|
|
.BR strdup ()
|
|
|
|
conforms to SVr4, 4.3BSD, POSIX.1-2001.
|
2007-05-12 09:06:04 +00:00
|
|
|
.BR strndup (),
|
|
|
|
.BR strdupa (),
|
|
|
|
and
|
|
|
|
.BR strndupa ()
|
|
|
|
are GNU extensions.
|
2004-11-03 13:51:07 +00:00
|
|
|
.SH "SEE ALSO"
|
|
|
|
.BR alloca (3),
|
|
|
|
.BR calloc (3),
|
|
|
|
.BR free (3),
|
|
|
|
.BR malloc (3),
|
2006-02-09 20:57:44 +00:00
|
|
|
.BR realloc (3),
|
index.3, stpcpy.3, strcasecmp.3, strcat.3, strchr.3, strcmp.3, strcoll.3, strcpy.3, strdup.3, strfry.3, strpbrk.3, strsep.3, strspn.3, strstr.3, strtok.3, strxfrm.3: SEE ALSO: Add reference to string(3)
The idea here is to provide a route to discover other
string functions.
Reported-by: Mark Hills <mark@pogo.org.uk>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
2010-09-12 14:39:58 +00:00
|
|
|
.BR string (3),
|
2007-07-08 12:11:40 +00:00
|
|
|
.BR wcsdup (3)
|