====== OSA : OS_Msg_Check ======
<color blue>**bool OS_Msg_Check (msg_cb)**</color>\\ 
<color blue>**bool OS_Msg_Check_I (msg_cb)**</color>\\ 
=== ===


Check if //msg_cb// exists.


=== Call allowed: ===
Everywhere


=== Parameters: ===
{| class = "fpl"
|-
|//''msg_cb''//
|Pointer to message descriptor. Variable of ##[[en:osa:ref:description:data_types#OST_MSG_CB|OST_MSG_CB]]## type
|}


=== Returns: ===
{| class = "fpl"
|-
|//''false''//
| message does not exist
|-
|//''true''//
| message exists
|}


=== Example: ===
<code cpp>
OST_MSG_CB msg_cb;

void Task (void)
{
    OST_MSG msg;
    for (;;) {
        /*...*/
        if (OS_Msg_Check (msg_cb)) {     // If message exists
            OS_Msg_Accept(msg_cb, msg);  // then accept it.
            /*...*/
        };
        /*...*/
    }
}
</code>


=== Old style name ===
<color gray>**OS_CheckMsg**</color>\\ 








=== See also ===
  * [[en:osa:ref:allservices:OS_Msg_Create|OS_Msg_Create]]

  * [[en:osa:ref:allservices:OS_Msg_Send|OS_Msg_Send]]
  * [[en:osa:ref:allservices:OS_Msg_Send_TO|OS_Msg_Send_TO]]
  * [[en:osa:ref:allservices:OS_Msg_Send_Now|OS_Msg_Send_Now]]


  * [[en:osa:ref:allservices:OS_Msg_Accept|OS_Msg_Accept]]

  * [[en:osa:ref:allservices:OS_Msg_Wait|OS_Msg_Wait]]
  * [[en:osa:ref:allservices:OS_Msg_Wait_TO|OS_Msg_Wait_TO]]

----
  * [[en:osa:ref:services:alphabetical|Alphabetical]]
  * [[en:osa:ref:services:brieflist|All services]]
~~UP~~