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NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | CONFORMING TO | SEE ALSO | COLOPHONThe Linux Programming Interface

STRDUP(3)                 Linux Programmer's Manual                STRDUP(3)

NAME         top

       strdup, strndup, strdupa, strndupa - duplicate a string

SYNOPSIS         top

       #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         top

       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).

RETURN VALUE         top

       The strdup() function returns a pointer to the duplicated string, or
       NULL if insufficient memory was available.

ERRORS         top

       ENOMEM Insufficient memory available to allocate duplicate string.

CONFORMING TO         top

       strdup() conforms to SVr4, 4.3BSD, POSIX.1-2001.  strndup() conforms
       to POSIX.1-2008.  strdupa() and strndupa() are GNU extensions.

SEE ALSO         top

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

COLOPHON         top

       This page is part of release 3.51 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                              2012-05-10                        STRDUP(3)

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