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);

   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

       strdup():
           _XOPEN_SOURCE >= 500
               || /* Since glibc 2.12: */ _POSIX_C_SOURCE >= 200809L
               || /* Glibc versions <= 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

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 ('\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

       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(), │ Thread safety │ MT-Safe │
       │strndupa()                      │               │         │
       └────────────────────────────────┴───────────────┴─────────┘

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)

COLOPHON

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