1STRDUP(3)                  Linux Programmer's Manual                 STRDUP(3)
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NAME

6       strdup, strndup, strdupa, strndupa - duplicate a string
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SYNOPSIS

9       #include <string.h>
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11       char *strdup(const char *s);
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13       char *strndup(const char *s, size_t n);
14       char *strdupa(const char *s);
15       char *strndupa(const char *s, size_t n);
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17   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
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19       strdup():
20           _SVID_SOURCE || _BSD_SOURCE || _XOPEN_SOURCE >= 500 ||
21           _XOPEN_SOURCE && _XOPEN_SOURCE_EXTENDED
22           || /* Since glibc 2.12: */ _POSIX_C_SOURCE >= 200809L
23       strndup():
24           Since glibc 2.10:
25               POSIX_C_SOURCE >= 200809L || _XOPEN_SOURCE >= 700
26           Before glibc 2.10:
27               _GNU_SOURCE
28       strdupa(), strndupa(): _GNU_SOURCE
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DESCRIPTION

31       The strdup() function returns a pointer to a  new  string  which  is  a
32       duplicate  of the string s.  Memory for the new string is obtained with
33       malloc(3), and can be freed with free(3).
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35       The strndup() function is similar, but copies at most n bytes.  If s is
36       longer  than  n,  only  n bytes are copied, and a terminating null byte
37       ('\0') is added.
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39       strdupa() and strndupa() are similar, but use alloca(3) to allocate the
40       buffer.  They are available only when using the GNU GCC suite, and suf‐
41       fer from the same limitations described in alloca(3).
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RETURN VALUE

44       On success, the strdup() function returns a pointer to  the  duplicated
45       string.   It  returns  NULL  if insufficient memory was available, with
46       errno set to indicate the cause of the error.
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ERRORS

49       ENOMEM Insufficient memory available to allocate duplicate string.
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CONFORMING TO

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

56       alloca(3),  calloc(3),  free(3), malloc(3), realloc(3), string(3), wcs‐
57       dup(3)
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COLOPHON

60       This page is part of release 3.53 of the Linux  man-pages  project.   A
61       description  of  the project, and information about reporting bugs, can
62       be found at http://www.kernel.org/doc/man-pages/.
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66GNU                               2013-04-19                         STRDUP(3)
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