{
    "mode": "man",
    "parameter": "FADVISE",
    "section": "1",
    "url": "https://www.chedong.com/phpMan.php/man/FADVISE/1/json",
    "generated": "2026-10-21T15:19:46Z",
    "synopsis": "fadvise [-a advice] [-o offset] [-l length] filename\nfadvise [-a advice] [-o offset] [-l length] -d file-descriptor",
    "sections": {
        "NAME": {
            "content": "fadvise - utility to use the posixfadvise system call\n",
            "subsections": []
        },
        "SYNOPSIS": {
            "content": "fadvise [-a advice] [-o offset] [-l length] filename\n\nfadvise [-a advice] [-o offset] [-l length] -d file-descriptor\n",
            "subsections": []
        },
        "DESCRIPTION": {
            "content": "fadvise is a simple command wrapping posixfadvise system call that is for predeclaring an\naccess pattern for file data.\n",
            "subsections": []
        },
        "OPTIONS": {
            "content": "",
            "subsections": [
                {
                    "name": "-d --fd _",
                    "content": "Apply the advice to the file specified with the file descriptor instead of open a file\nspecified with a file name.\n",
                    "flag": "-d",
                    "long": "--fd"
                },
                {
                    "name": "-a --advice _",
                    "content": "See the command output with --help option for available values for advice. If this option\nis omitted, \"dontneed\" is used as default advice.\n",
                    "flag": "-a",
                    "long": "--advice"
                },
                {
                    "name": "-o --offset _",
                    "content": "Specifies the beginning offset of the range, in bytes. If this option is omitted, 0 is\nused as default advice.\n",
                    "flag": "-o",
                    "long": "--offset"
                },
                {
                    "name": "-l --length _",
                    "content": "Specifies the length of the range, in bytes. If this option is omitted, 0 is used as\ndefault advice.\n",
                    "flag": "-l",
                    "long": "--length"
                },
                {
                    "name": "-h --help",
                    "content": "Display help text and exit.\n",
                    "flag": "-h",
                    "long": "--help"
                },
                {
                    "name": "-V --version",
                    "content": "Print version and exit.\n",
                    "flag": "-V",
                    "long": "--version"
                }
            ]
        },
        "EXIT STATUS": {
            "content": "fadvise has the following exit status values:\n\n0\nsuccess\n\n1\nunspecified failure\n",
            "subsections": []
        },
        "AUTHORS": {
            "content": "Masatake YAMATO <yamato@redhat.com>\n",
            "subsections": []
        },
        "SEE ALSO": {
            "content": "posixfadvise(2)\n",
            "subsections": []
        },
        "REPORTING BUGS": {
            "content": "For bug reports, use the issue tracker at https://github.com/util-linux/util-linux/issues.\n",
            "subsections": []
        },
        "AVAILABILITY": {
            "content": "The fadvise command is part of the util-linux package which can be downloaded from Linux\nKernel Archive <https://www.kernel.org/pub/linux/utils/util-linux/>.\n\nutil-linux 2.39.3                            2023-11-21                                   FADVISE(1)",
            "subsections": []
        }
    },
    "summary": "fadvise - utility to use the posixfadvise system call",
    "flags": [
        {
            "flag": "-d",
            "long": "--fd",
            "arg": null,
            "description": "Apply the advice to the file specified with the file descriptor instead of open a file specified with a file name."
        },
        {
            "flag": "-a",
            "long": "--advice",
            "arg": null,
            "description": "See the command output with --help option for available values for advice. If this option is omitted, \"dontneed\" is used as default advice."
        },
        {
            "flag": "-o",
            "long": "--offset",
            "arg": null,
            "description": "Specifies the beginning offset of the range, in bytes. If this option is omitted, 0 is used as default advice."
        },
        {
            "flag": "-l",
            "long": "--length",
            "arg": null,
            "description": "Specifies the length of the range, in bytes. If this option is omitted, 0 is used as default advice."
        },
        {
            "flag": "-h",
            "long": "--help",
            "arg": null,
            "description": "Display help text and exit."
        },
        {
            "flag": "-V",
            "long": "--version",
            "arg": null,
            "description": "Print version and exit."
        }
    ],
    "examples": [],
    "see_also": [
        {
            "name": "posixfadvise",
            "section": "2",
            "url": "https://www.chedong.com/phpMan.php/man/posixfadvise/2/json"
        }
    ],
    "tldr": {
        "source": "official",
        "description": "Control Linux file caching behavior.",
        "examples": [
            {
                "description": "Preload a file or directory into cache",
                "command": "fadvise {{-a|--advice}} willneeded {{path/to/file_or_directory}}"
            },
            {
                "description": "Suggest dropping a file from cache",
                "command": "fadvise {{path/to/file}}"
            },
            {
                "description": "Display help",
                "command": "fadvise {{-h|--help}}"
            }
        ]
    }
}