| NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | CONFORMING TO | SEE ALSO | COLOPHON | The Linux Programming Interface |
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():
_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
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).
The strdup() function returns a pointer to the duplicated string, or NULL if
insufficient memory was available.
ENOMEM Insufficient memory available to allocate duplicate string.
strdup() conforms to SVr4, 4.3BSD, POSIX.1-2001. strndup(), 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 3.32 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/.
GNU 2010-09-26 STRDUP(3)
HTML rendering created 2010-12-03 by Michael Kerrisk, author of The Linux Programming Interface