---
name: "explain_fcntl_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_fcntl_or_die"
---

# explain\_fcntl\_or\_die(3)

manipulate a file descriptor and report errors

## NAME

explain\_fcntl\_or\_die - manipulate a file descriptor and report errors

## SYNOPSIS

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

int explain\_fcntl\_or\_die(int fildes, int command, long arg);

## DESCRIPTION

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

This function is intended to be used in a fashion similar to the following example:

```
int result = explain_fcntl_or_die(fildes, command, arg);
```

- *fildes*

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

- *command*

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

- *arg*

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

- Returns:

  This function only returns on success, and it returns whatever was returned by the [fcntl(2)](/fcntl/2.md) call; depending on the command, this may have no use. On failure, prints an explanation and exits, it does not return.

## SEE ALSO

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

  manipulate a file descriptor

- [*explain\_fcntl*(3)](/explain_fcntl/3.md)

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

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

  terminate the calling process

## COPYRIGHT

libexplain version 1.4\
 Copyright (C) 2008 Peter Miller