strdup(3)                  Library Functions Manual                  strdup(3)

NAME
       strdup - string duplicate

LIBRARY
       Standard C library (libc, -lc)

SYNOPSIS
       #include <string.h>

       char *strdup(const char *s);

   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

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).

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 error.

ERRORS
       See malloc(3).

ATTRIBUTES
       For an explanation of the terms used in this section, see
       attributes(7).

       +--------------------------------------------+---------------+---------+
       |Interface                                   | Attribute     | Value   |
       +--------------------------------------------+---------------+---------+
       |strdup ()                                   | Thread safety | MT-Safe |
       +--------------------------------------------+---------------+---------+
STANDARDS
       POSIX.1-2008.

HISTORY
       SVr4, 4.3BSD-Reno, POSIX.1-2001.

SEE ALSO
       malloc(3), string(3), strdupa(3), wcsdup(3)

Linux man-pages 6.19              2026-08-10                         strdup(3)