strndupa(3) - Linux man page

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);

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 only 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 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() conforms to POSIX.1-2008. strdupa() and strndupa() are GNU extensions.

See Also

alloca(3), calloc(3), free(3), malloc(3), realloc(3), string(3), wcsdup(3)