strdup (3)
Leading comments
Copyright 1993 David Metcalfe (david@prism.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. Sin...
NAME
strdup, strndup, strdupa, strndupa - duplicate a stringSYNOPSIS
#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():
-
_SVID_SOURCE || _BSD_SOURCE || _XOPEN_SOURCE >= 500 ||
_XOPEN_SOURCE && _XOPEN_SOURCE_EXTENDED
|| /* Since glibc 2.12: */ _POSIX_C_SOURCE >= 200809L
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 copies at most n bytes. If s is longer than n, only n bytes are copied, and a terminating null byte (aq\0aq) 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).
RETURN VALUE
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.ERRORS
- ENOMEM
- Insufficient memory available to allocate duplicate string.
ATTRIBUTES
For an explanation of the terms used in this section, see attributes(7).| Interface | Attribute | Value |
|
strdup(),
strndup(),
strdupa(),
strndupa() | Thread safety | MT-Safe |