---
name: "rbflook"
section: "2"
platform: "linux"
package: "lam2-dev"
version: "6.3.2-3"
release: "Debian 2.2 (Potato)"
platforms: ["linux"]
url: "https://new.carta.tech/rbflook"
---

# rbflook(2)

Retrieve a copy of a buffered LAM message packet.

## NAME

rbflook - Retrieve a copy of a buffered LAM message packet.

## SYNOPSIS

\#include \<net.h\>

int rbflook (int node, struct nmsg \*nh, int seq);

## DESCRIPTION

The message packet is identified solely by a sequence number, *seq*. Sequence numbers of buffered packets are learned by a prior call to [rbfstate(2)](/rbfstate/2.md). Note that the packets and their sequence numbers reported by [rbfstate(2)](/rbfstate/2.md) are only a snapshot of a buffer daemon's state. When *rbflook()* is called, some or all of packets reported by [rbfstate(2)](/rbfstate/2.md) may have been forwarded and new ones (with unknown sequence numbers) may have arrived. The most useful application of *rbflook()* is to debug a blocked system of processes and messages.

The *nh* argument is a network message descriptor that is only used to supply a packet buffer and maximum packet length (up to MAXNMSGLEN, defined in \<net.h\>). The synchronization fields of the descriptor are not used. Only the sequence number identifies the message packet.

## ERRORS

- EWOULDBLOCK

  No message packet with the supplied sequence number could be found.

## SEE ALSO

[rbfstate(2)](/rbfstate/2.md)