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NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | ATTRIBUTES | CONFORMING TO | SEE ALSO | COLOPHON |
STRDUP(3) Linux Programmer's Manual STRDUP(3)
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);
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
strdup():
_XOPEN_SOURCE >= 500
|| /* Since glibc 2.12: */ _POSIX_C_SOURCE >= 200809L
|| /* Glibc versions <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE
strndup():
Since glibc 2.10:
_POSIX_C_SOURCE >= 200809L
Before glibc 2.10:
_GNU_SOURCE
strdupa(), strndupa(): _GNU_SOURCE
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.
ENOMEM Insufficient memory available to allocate duplicate string.
For an explanation of the terms used in this section, see
attributes(7).
┌────────────────────────────────┬───────────────┬─────────┐
│Interface │ Attribute │ Value │
├────────────────────────────────┼───────────────┼─────────┤
│strdup(), strndup(), strdupa(), │ Thread safety │ MT-Safe │
│strndupa() │ │ │
└────────────────────────────────┴───────────────┴─────────┘
strdup() conforms to SVr4, 4.3BSD, POSIX.1-2001. strndup() conforms
to POSIX.1-2008. strdupa() and strndupa() are GNU extensions.
alloca(3), calloc(3), free(3), malloc(3), realloc(3), string(3),
wcsdup(3)
This page is part of release 4.12 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/.
GNU 2016-03-15 STRDUP(3)
Pages that refer to this page: ldap_memory(3), pmdadaemon(3), pmdafetch(3), pmfault(3), pmtraversepmns(3), strcpy(3), string(3), wcsdup(3)