fstyp

- determine file system type

Synopsis

fstyp [-a | -v] special [:logical-drive]

Description

fstyp allows the user to determine the file system type of unmounted file systems using heuristic programs.

An fstyp module for each file system type to be checked is executed; each of these modules applies an appropriate heuristic to determine whether the supplied special file is of the type for which it checks. If it is, the program prints on standard output the usual file system identifier for that type (for example, ``ufs'') and exits with a return code of 0; if none of the modules succeed, the error message unknown_fstyp (no matches) is returned and the exit status is 1. If more than one module succeeds, the error message unknown_fstyp (multiple matches) is returned and the exit status is 2. Other errors are printed in the same format.

This command is unreliable and its results should not be used to make any decisions about subsequent use of a storage device or disk partition.

Options

-a

Output all available file system attributes. If a file system has been successfully identified, and this option is specified, the FSType identifier is followed by one or more “name-value” pairs, one per line, in the format:

name: value

The following conventions are recognized for the file system attributes:

• String values are put in single quotes.

• Nested “name-value” list increases the indentation of its values by four whitespaces.

• For an array of “name-value” pairs, one array entry is printed per line, with the index following the name in square brackets.

For instance, in the following example, “top_list” is a “name-value” list, consisting of a string array “string_array” and a “name-value” list array “list_array”. The second “list_array”element is an integer array “int_array” containing three elements.

top_string: 'String'
top_list:
    string_array[0]: 'S0'
    string_array[1]: 'S1'
    list_array[0]:
        int_one: 1
        string_two: 'S2'
    list_array[1]:
        int_array[0]: 1
        int_array[1]: 2
        int_array[2]: 3

In addition to the FSType-specific attributes, the following generic attributes may be present:

gen_clean

Allowable values are “true” or “false”. If the value is “false”, the file system is damaged or was not unmounted cleanly and the fsck(1M) command must be run before this file system can be mounted.

gen_guid

Globally unique identifier. This string uniquely identifies the file system.

gen_version

A string describing the file system version.

gen_volume_label

Volume label, a human-readable string used to either describe or identify the file system.

-v

Produce verbose output. This is usually information about the file systems superblock and varies across different FSTypes. See ufs(7FS), mkfs_ufs(1M), and tunefs(1M) for details.

Usage

See largefile(5) for the description of the behavior of fstyp when encountering files greater than or equal to 2 Gbyte ( 2³¹ bytes).

Attributes

See attributes(5) for descriptions of the following attributes:

See Also

fsck(1M), mkfs_ufs(1M), tunefs(1M), attributes(5), libfstyp(3LIB), largefile(5), hsfs(7FS), ufs(7FS), pcfs(7FS)

Notes

The use of heuristics implies that the result offstyp is not guaranteed to be accurate.

This command is unreliable and its results should not be used to make any decisions about subsequent use of a storage device or disk partition.