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

# nprobe(2)

Report if a LAM bufferd network message is ready to be received.

## NAME

nprobe - Report if a LAM bufferd network message is ready to be received.

## C SYNOPSIS

\#include \<net.h\>

int nprobe (struct nmsg \*header);

## FORTRAN SYNOPSIS

subroutine NPROB (nevent, ntype, nlength, nflags, nready, ierror)

integer nevent, ntype, nlength, nflags, nready, ierror

## DESCRIPTION

If a synchronizing message exists, information about its type, length, and flags is returned.

The *nprobe()* function accepts a pointer to a network message descriptor, defined in \<net.h\>. See [nsend(2)](/nsend/2.md). Only the *nh\_event* and *nh\_type* fields of the network message descriptor must be filled before calling *nprobe()*. The *nh\_type* and *nh\_length* fields are altered after a successful probe as if [nrecv(2)](/nrecv/2.md) had been called.

Since *nprobe()* can only examine buffered messages, it cannot be used when buffers are bypassed.

## C RETURN VALUE

Upon successful completion, 1 is returned if a synchronizing message is waiting to be received, and 0 is returned if no synchronizing message is waiting. If an error occurred, -1 is returned and the global variable, *errno* is set to indicate the error.

## FORTRAN RETURN VALUE

Upon successful completion, the *nready* argument is set to 1 if a synchronizing message is waiting to be received, and 0 if no synchronizing message is waiting.

## SEE ALSO

[bfctl(1)](/bfctl/1.md), [nsend(2)](/nsend/2.md)