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man:strdup

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

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 suf-
     fer 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),  wcs-
     dup(3)

COLOPHON

     This  page  is  part of release 4.16 of the Linux man-pages project.  A
     description of the project, information about reporting bugs,  and  the
     latest     version     of     this    page,    can    be    found    at
     https://www.kernel.org/doc/man-pages/.

GNU 2017-09-15 STRDUP(3)

/data/webs/external/dokuwiki/data/pages/man/strdup.txt · Last modified: 2019/05/17 09:32 by 127.0.0.1

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