NAME

mq_unlink − Removes a message queue (P1003.1b)

SYNOPSIS

#include <mqueue.h>
 
int mq_unlink (
const char ∗name);

LIBRARY

Realtime Library (librt.so, librt.a)

PARAMETERS

∗name
Specifies a pointer to the pathname of a message queue.

DESCRIPTION

The mq_unlink function removes a message queue named by the pathname. After a successful call to this function, subsequent calls to the mq_open function fail if they specify the queue identified by the name argument and the O_CREAT option is not set. 

Close the connection to the queue with a call to the mq_close function before calling the mq_unlink function.  If one or more processes have the message queue open when mq_unlink is called, destruction of the queue is postponed until all references to the message queue are removed. In this situation, the mq_unlink function returns immediately, without waiting for all queue references to be closed. 

RETURN VALUES

On successful completion, the function returns the value 0 (zero); otherwise, the function returns the value −1, sets errno to indicate the error, and the message queue remains. 

ERRORS

The mq_unlink function fails under the following conditions:

[EACCES]
Permission is denied to unlink the message queue.

[ENAMETOOLONG]
The length of the name string exceeds {NAME_MAX} while {_POSIX_NO_TRUNC} is in effect. 

[ENOENT]
The named message queue does not exist.

Additionally, any error that can be returned by the open or fstat file system calls can be returned by the mq_unlink function. 

SEE ALSO

Functions: mq_close(3), mq_open(3)

Guide to Realtime Programming