strdup, strndup, strdupa, strndupa - duplicate a string

       For an explanation of the terms used in this section, see attributes(7).
       ┌─────────────────────────────────────────────────────────────────────────────┬───────────────┬─────────┐
       │ Interface                                                                   │ Attribute     │ Value   │
       ├─────────────────────────────────────────────────────────────────────────────┼───────────────┼─────────┤
       │ strdup(), strndup(), strdupa(), strndupa()                                  │ Thread safety │ MT-Safe │
       └─────────────────────────────────────────────────────────────────────────────┴───────────────┴─────────┘

       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.

ENOMEM Insufficient memory available to allocate duplicate string.

strdup()
              SVr4, 4.3BSD-Reno, POSIX.1-2001.

       strndup()
              POSIX.1-2008.

       strdupa()
       strndupa()
              GNU.

       Standard C library (libc, -lc)

       strdup, strndup, strdupa, strndupa - duplicate a string

       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 error.

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

Linux man-pages 6.9.1                              2024-06-15                                          strdup(3)

strdup()
       strndup()
              POSIX.1-2008.

       strdupa()
       strndupa()
              GNU.

#include<string.h>char*strdup(constchar*s);char*strndup(constchars[.n],size_tn);char*strdupa(constchar*s);char*strndupa(constchars[.n],size_tn);

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

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