---
name: "explain_shmat_or_die"
section: "3"
platform: "linux"
package: "libexplain-dev"
version: "1.4.D001-16"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/explain_shmat_or_die"
---

# explain\_shmat\_or\_die(3)

shared memory attach and report errors

## NAME

explain\_shmat\_or\_die - shared memory attach and report errors

## SYNOPSIS

\#include \<libexplain/shmat.h\>

void \*explain\_shmat\_or\_die(int shmid, const void \*shmaddr, int shmflg);\
 void \*explain\_shmat\_on\_error(int shmid, const void \*shmaddr, int shmflg);

## DESCRIPTION

The **explain\_shmat\_or\_die** function is used to call the [*shmat*(2)](/shmat/2.md) system call. On failure an explanation will be printed to *stderr*, obtained from the [*explain\_shmat*(3)](/explain_shmat/3.md) function, and then the process terminates by calling `exit(EXIT_FAILURE)`.

The **explain\_shmat\_on\_error** function is used to call the [*shmat*(2)](/shmat/2.md) system call. On failure an explanation will be printed to *stderr*, obtained from the [*explain\_shmat*(3)](/explain_shmat/3.md) function, but still returns to the caller.

- *shmid*

  The shmid, exactly as to be passed to the [*shmat*(2)](/shmat/2.md) system call.

- *shmaddr*

  The shmaddr, exactly as to be passed to the [*shmat*(2)](/shmat/2.md) system call.

- *shmflg*

  The shmflg, exactly as to be passed to the [*shmat*(2)](/shmat/2.md) system call.

## RETURN VALUE

The **explain\_shmat\_or\_die** function only returns on success, see [*shmat*(2)](/shmat/2.md) for more information. On failure, prints an explanation and exits, it does not return.

The **explain\_shmat\_on\_error** function always returns the value return by the wrapped [*shmat*(2)](/shmat/2.md) system call.

## EXAMPLE

The **explain\_shmat\_or\_die** function is intended to be used in a fashion similar to the following example:

```
void *result = explain_shmat_or_die(shmid, shmaddr, shmflg);
```

## SEE ALSO

- [*shmat*(2)](/shmat/2.md)

  shared memory attach

- [*explain\_shmat*(3)](/explain_shmat/3.md)

  explain [*shmat*(2)](/shmat/2.md) errors

- [*exit*(2)](/exit/2.md)

  terminate the calling process

## COPYRIGHT

libexplain version 1.4\
 Copyright (C) 2011 Peter Miller