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== Pair (Two Way Radio)

image::pair.png[Two Way Radio]

The pair pattern is used when there a one-to-one peer relationship.
Only one peer may be connected to another peer at a time, but both
may speak freely.

.pair.c
[source,c]
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include::src/pair.c[]
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<1> Blithely assumes message is ASCIIZ string. Real code should check it.

.Compilation
[source,bash]
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gcc pair.c -lnanomsg -o pair
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.Execution
[source,bash]
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./pair node0 ipc:///tmp/pair.ipc & node0=$!
./pair node1 ipc:///tmp/pair.ipc & node1=$!
sleep 3
kill $node0 $node1
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.Output
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node0: SENDING "node0"
node1: SENDING "node1"
node1: RECEIVED"node0"
node0: SENDING "node0"
node0: RECEIVED"node1"
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