strdup(3)

strdup3

String duplicate

Usage

#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

Library

Standard C library (libc, -lc)

Overview

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).

InterfaceAttributeValue
strdup()Thread safetyMT-Safe

Releases

19 releases since Debian 1.1 (Buzz); the text changed 13 times.

  1. 1.1–2.2
  2. 3.0
  3. 3.1
  4. 4.0
  5. 5.0
  6. 6.0
  7. 7
  8. 8
  9. 9
  10. 10
  11. 11
  12. 12
  13. 13
  14. Arch

Standards

POSIX.1-2008.

History

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

From man-pages 6.19-1 in Arch Linux 2026-11-01. Parsed by carta from the page's man source.