---
name: "explain_flock_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_flock_or_die"
---

# explain\_flock\_or\_die(3)

control advisory lock on open file and report errors

## NAME

explain\_flock\_or\_die - control advisory lock on open file and report errors

## SYNOPSIS

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

void explain\_flock\_or\_die(int fildes, int command);\
 int explain\_flock\_on\_error(int fildes, int command))

## DESCRIPTION

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

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

- *fildes*

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

- *command*

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

## RETURN VALUE

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

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

## EXAMPLE

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

```
explain_flock_or_die(fildes, command);
```

## SEE ALSO

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

  apply or remove an advisory lock on an open file

- [*explain\_flock*(3)](/explain_flock/3.md)

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

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

  terminate the calling process

## COPYRIGHT

libexplain version 1.4\
 Copyright (C) 2009 Peter Miller