PROLOG | NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | EXAMPLES | APPLICATION USAGE | RATIONALE | FUTURE DIRECTIONS | SEE ALSO | COPYRIGHT

STRDUP(3P)                POSIX Programmer's Manual               STRDUP(3P)

PROLOG         top

       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         top

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

SYNOPSIS         top

       #include <string.h>

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

DESCRIPTION         top

       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         top

       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         top

       These functions shall fail if:

       ENOMEM Storage space available is insufficient.

       The following sections are informative.

EXAMPLES         top

       None.

APPLICATION USAGE         top

       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         top

       None.

FUTURE DIRECTIONS         top

       None.

SEE ALSO         top

       free(3p), wcsdup(3p)

       The Base Definitions volume of POSIX.1‐2008, string.h(0p)

COPYRIGHT         top

       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 .

IEEE/The Open Group                 2013                          STRDUP(3P)