STRDUP
Section: Linux Programmer's Manual (3)
Updated: 2010-09-15
NAME
strdup, strndup, strdupa, strndupa - duplicate a string
SYNOPSIS
#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);
Feature Test Macro Requirements for glibc (see
feature_test_macros(7)):
strdup():
-
- Since glibc 2.12:
-
_SVID_SOURCE || _BSD_SOURCE || _XOPEN_SOURCE >= 500 ||
_XOPEN_SOURCE && _XOPEN_SOURCE_EXTENDED ||
_POSIX_C_SOURCE >= 200809L
- Before glibc 2.12:
-
_SVID_SOURCE || _BSD_SOURCE || _XOPEN_SOURCE >= 500 ||
_XOPEN_SOURCE && _XOPEN_SOURCE_EXTENDED
strndup():
-
- Since glibc 2.10:
-
POSIX_C_SOURCE >= 200809L || _XOPEN_SOURCE >= 700
- Before glibc 2.10:
-
_GNU_SOURCE
strdupa(),
strndupa():
_GNU_SOURCE
DESCRIPTION
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 only copies at most
n characters.
If s is longer than n, only n
characters 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 only available when using the GNU
GCC suite, and suffer from the same limitations described in
alloca(3).
RETURN VALUE
The
strdup()
function returns a pointer to the duplicated
string, or NULL if insufficient memory was available.
ERRORS
- ENOMEM
-
Insufficient memory available to allocate duplicate string.
CONFORMING TO
strdup()
conforms to SVr4, 4.3BSD, POSIX.1-2001.
strndup(),
strdupa(),
and
strndupa()
are GNU extensions.
SEE ALSO
alloca(3),
calloc(3),
free(3),
malloc(3),
realloc(3),
string(3),
wcsdup(3)
COLOPHON
This page is part of release 3.27 of the Linux
man-pages
project.
A description of the project,
and information about reporting bugs,
can be found at
http://www.kernel.org/doc/man-pages/.
Index
- NAME
-
- SYNOPSIS
-
- DESCRIPTION
-
- RETURN VALUE
-
- ERRORS
-
- CONFORMING TO
-
- SEE ALSO
-
- COLOPHON
-
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Time: 07:35:18 GMT, March 26, 2013