PROLOG

       This  manual  page  is part of the POSIX Programmer's Manual.  The Linux implementation of
       this interface may differ (consult the corresponding Linux  manual  page  for  details  of
       Linux behavior), or the interface may not be implemented on Linux.

NAME

       strdup, strndup — duplicate a specific number of bytes from a string

SYNOPSIS

       #include <string.h>

       char *strdup(const char *s);
       char *strndup(const char *s, size_t size);

DESCRIPTION

       The  strdup() function shall return a pointer to a new string, which is a duplicate of the
       string pointed to by s.  The returned pointer can be passed to free().  A null pointer  is
       returned if the new string cannot be created.

       The  strndup()  function  shall  be  equivalent  to the strdup() function, duplicating the
       provided s in a new block of memory allocated as if by using malloc(), with the  exception
       being  that  strndup() copies at most size plus one bytes into the newly allocated memory,
       terminating the new string with a NUL character. If the length of s is larger  than  size,
       only  size bytes shall be duplicated. If size is larger than the length of s, all bytes in
       s shall be copied into the new memory buffer, including the terminating NUL character. The
       newly created string shall always be properly terminated.

RETURN VALUE

       The  strdup()  function  shall  return a pointer to a new string on success. Otherwise, it
       shall return a null pointer and set errno to indicate the error.

       Upon successful completion, the strndup() function shall return a  pointer  to  the  newly
       allocated  memory  containing  the  duplicated  string.  Otherwise, it shall return a null
       pointer and set errno to indicate the error.

ERRORS

       These functions shall fail if:

       ENOMEM Storage space available is insufficient.

       The following sections are informative.

EXAMPLES

       None.

APPLICATION USAGE

       For functions that allocate memory as if by malloc(), the application should release  such
       memory  when  it  is  no longer required by a call to free().  For strdup() and strndup(),
       this is the return value.

RATIONALE

       None.

FUTURE DIRECTIONS

       None.

SEE ALSO

       free(), wcsdup()

       The Base Definitions volume of POSIX.1‐2008, <string.h>

COPYRIGHT

       Portions of this text are reprinted and  reproduced  in  electronic  form  from  IEEE  Std
       1003.1,  2013  Edition,  Standard  for Information Technology -- Portable Operating System
       Interface (POSIX), The Open Group Base Specifications Issue 7, Copyright (C) 2013  by  the
       Institute  of  Electrical  and  Electronics  Engineers,  Inc and The Open Group.  (This is
       POSIX.1-2008 with the  2013  Technical  Corrigendum  1  applied.)  In  the  event  of  any
       discrepancy  between  this  version and the original IEEE and The Open Group Standard, the
       original IEEE and The Open Group Standard is the referee document. The  original  Standard
       can be obtained online at http://www.unix.org/online.html .

       Any  typographical  or  formatting errors that appear in this page are most likely to have
       been introduced during the conversion of the source files to man page  format.  To  report
       such errors, see https://www.kernel.org/doc/man-pages/reporting_bugs.html .