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NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | ATTRIBUTES | CONFORMING TO | SEE ALSO | COLOPHON |
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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 <= 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 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 5.13 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 2021-03-22 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)
Copyright and license for this manual page
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