docs/rmr_get_xact.3.rst

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============================================================================================
Man Page: rmr_get_xact
============================================================================================




RMR LIBRARY FUNCTIONS
=====================



NAME
----

rmr_get_xact


SYNOPSIS
--------


::

  #include <rmr/rmr.h>

  char* rmr_get_xact( rmr_mbuf_t* mbuf, unsigned char* dest )



DESCRIPTION
-----------

The ``rmr_get_xact`` function will copy the transaction field
from the message into the *dest* buffer provided by the user.
The buffer referenced by *dest* is assumed to be at least
``RMR_MAX_XID`` bytes in length. If *dest* is NULL, then a
buffer is allocated (the calling application is expected to
free when the buffer is no longer needed).


RETURN VALUE
------------

On success, a pointer to the extracted string is returned. If
*dest* was supplied, then this is just a pointer to the
caller's buffer. If *dest* was NULL, this is a pointer to the
allocated buffer. If an error occurs, a nil pointer is
returned and errno is set as described below.


ERRORS
------

If an error occurs, the value of the global variable
``errno`` will be set to one of the following with the
indicated meaning.

    .. list-table::
      :widths: auto
      :header-rows: 0
      :class: borderless

      * - **EINVAL**
        -
          The message, or an internal portion of the message, was
          corrupted or the pointer was invalid.

      * - **ENOMEM**
        -
          A nil pointer was passed for *dest,* however it was not
          possible to allocate a buffer using malloc().




SEE ALSO
--------

rmr_alloc_msg(3), rmr_bytes2xact(3), rmr_bytes2meid(3),
rmr_call(3), rmr_free_msg(3), rmr_get_rcvfd(3),
rmr_get_meid(3), rmr_payload_size(3), rmr_send_msg(3),
rmr_rcv_msg(3), rmr_rcv_specific(3), rmr_rts_msg(3),
rmr_ready(3), rmr_fib(3), rmr_has_str(3), rmr_tokenise(3),
rmr_mk_ring(3), rmr_ring_free(3), rmr_str2meid(3),
rmr_str2xact(3), rmr_wh_open(3), rmr_wh_send_msg(3)