FADVISE(1) User Commands FADVISE(1)

# [NAME](#NAME)

fadvise - utility to use the \*posix\_fadvise\*(2) system call

# [SYNOPSIS](#SYNOPSIS)

**fadvise** \[**-a** *advice*] \[**-o** *offset*] \[**-l** *length*] *filename*

**fadvise** \[**-a** *advice*] \[**-o** *offset*] \[**-l** *length*] -d *file-descriptor*

# [DESCRIPTION](#DESCRIPTION)

**fadvise** is a simple command wrapping [**posix\_fadvise**(2)](/man/os/util-linux/posix_fadvise.2) system call that is for predeclaring an access pattern for file data.

# [OPTIONS](#OPTIONS)

**-d**, **--fd** *file-descriptor*

Apply the advice to the file specified with the file descriptor instead of open a file specified with a file name.

**-a**, **--advice** *advice*

See the command output with **--help** option for available values for advice. If this option is omitted, "dontneed" is used as default advice.

**-o**, **--offset** *offset*

Specifies the beginning offset of the range, in bytes. If this option is omitted, 0 is used as default advice.

**-l**, **--length** *length*

Specifies the length of the range, in bytes. If this option is omitted, 0 is used as default advice.

**-h**, **--help**

Display help text and exit.

**-V**, **--version**

Display version and exit.

# [EXIT STATUS](#EXIT_STATUS)

**fadvise** has the following exit status values:

**0**

success

**1**

unspecified failure

# [AUTHORS](#AUTHORS)

*Masatake YAMATO* <yamato@redhat.com>

# [SEE ALSO](#SEE_ALSO)

[**posix\_fadvise**(2)](/man/os/util-linux/posix_fadvise.2)

# [REPORTING BUGS](#REPORTING_BUGS)

For bug reports, use the *issue tracker* <https://github.com/util-linux/util-linux/issues>.

# [AVAILABILITY](#AVAILABILITY)

The **fadvise** command is part of the util-linux package which can be downloaded from *Linux Kernel Archive* <https://www.kernel.org/pub/linux/utils/util-linux/>.

2026-09-25 util-linux 2.42.4

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Document: fadvise(1) from util-linux 2.42.4-r0 (Chainguard OS)