1ZMQ_IPC(7) 0MQ Manual ZMQ_IPC(7)
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6 zmq_ipc - 0MQ local inter-process communication transport
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9 The inter-process transport passes messages between local processes
10 using a system-dependent IPC mechanism.
11 Note
13 The inter-process transport is currently only implemented on
14 operating systems that provide UNIX domain sockets.
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17 A 0MQ endpoint is a string consisting of a transport:// followed by an
18 address. The transport specifies the underlying protocol to use. The
19 address specifies the transport-specific address to connect to.
20 For the inter-process transport, the transport is ipc, and the meaning
22 of the address part is defined below.
23 Binding a socket
25 When binding a socket to a local address using zmq_bind() with the ipc
26 transport, the endpoint shall be interpreted as an arbitrary string
27 identifying the pathname to create. The pathname must be unique within
28 the operating system namespace used by the ipc implementation, and must
29 fulfill any restrictions placed by the operating system on the format
30 and length of a pathname.
31 When the address is wild-card *, zmq_bind() shall generate a unique
33 temporary pathname. The caller should retrieve this pathname using the
34 ZMQ_LAST_ENDPOINT socket option. See zmq_getsockopt(3) for details.
35 Note
37 any existing binding to the same endpoint shall be overridden. That
38 is, if a second process binds to an endpoint already bound by a
39 process, this will succeed and the first process will lose its
40 binding. In this behaviour, the ipc transport is not consistent
41 with the tcp or inproc transports.
42 Note
44 the endpoint pathname must be writable by the process. When the
45 endpoint starts with /, e.g., ipc:///pathname, this will be an
46 absolute pathname. If the endpoint specifies a directory that does
47 not exist, the bind shall fail.
48 Note
50 on Linux only, when the endpoint pathname starts with @, the
51 abstract namespace shall be used. The abstract namespace is
52 independent of the filesystem and if a process attempts to bind an
53 endpoint already bound by a process, it will fail. See unix(7) for
54 details.
55 Note
57 IPC pathnames have a maximum size that depends on the operating
58 system. On Linux, the maximum is 113 characters including the
59 "ipc://" prefix (107 characters for the real path name).
60 Unbinding wild-card address from a socket
62 When wild-card * endpoint was used in zmq_bind(), the caller should use
63 real endpoint obtained from the ZMQ_LAST_ENDPOINT socket option to
64 unbind this endpoint from a socket using zmq_unbind().
65 Connecting a socket
67 When connecting a socket to a peer address using zmq_connect() with the
68 ipc transport, the endpoint shall be interpreted as an arbitrary string
69 identifying the pathname to connect to. The pathname must have been
70 previously created within the operating system namespace by assigning
71 it to a socket with zmq_bind().
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74 Assigning a local address to a socket.
75 // Assign the pathname "/tmp/feeds/0"
77 rc = zmq_bind(socket, "ipc:///tmp/feeds/0");
78 assert (rc == 0);
79 Connecting a socket.
81 // Connect to the pathname "/tmp/feeds/0"
83 rc = zmq_connect(socket, "ipc:///tmp/feeds/0");
84 assert (rc == 0);
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88 zmq_bind(3) zmq_connect(3) zmq_inproc(7) zmq_tcp(7) zmq_pgm(7)
89 zmq_vmci(7) zmq_getsockopt(3) zmq(7)
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92 This page was written by the 0MQ community. To make a change please
93 read the 0MQ Contribution Policy at
94 http://www.zeromq.org/docs:contributing.
950MQ 4.3.4 01/22/2022 ZMQ_IPC(7)