BITS(1) User Commands BITS(1)

# [NAME](#NAME)

bits - convert bit masks or lists from/to various formats

# [SYNOPSIS](#SYNOPSIS)

**bits** \[**-h**] \[**-V**] \[**-w** *number*] \[*mode*] \[*mask*|*list*]...

# [DESCRIPTION](#DESCRIPTION)

The **bits** utility converts between bit masks and bit lists. It supports combining multiple masks or lists using bitwise operations.

# [POSITIONAL ARGUMENTS](#POSITIONAL_ARGUMENTS)

*mask*

A set of bits specified as a hexadecimal mask value (for example: **0xeec2**).

*list*

A set of bits specified as a comma-separated list of bit IDs (for example: **1,5,29,32**).

If no argument is specified, the sets of bits will be read from standard input, one group per line.

Consecutive IDs can be compressed as ranges (for example: **5,6,7,8,9,10** → **5-10**).

Optionally, if an argument starts with a comma, it will be parsed as a single hexadecimal mask split in 32-bit groups (for example: **,00014000,00000000,00020000** → **17,78,80**).

By default, all groups will be OR’ed together. If a group has one of the prefixes **&**, **^**, or **~**, it will be combined with the resulting mask using a different binary operation:

**&mask**|**&list**

The group will be combined with a binary AND operation. That is: all bits that are set to 1 in the group AND in the combined groups so far will be preserved as 1. All other bits will be reset to 0.

**^mask**|**^list**

The group will be combined with a binary XOR operation. That is: all bits that are set to 1 in the group AND to 0 in the combined groups so far (or the other way around) will be set to 1. Bits that are set both to 1 or both to 0 will be reset to 0.

**~mask**|**~list**

All bits set to 1 in the group will be cleared (reset to 0) in the combined groups so far.

# [OPTIONS](#OPTIONS)

**-w** *number*, **--width** *number*

The maximum number of bits in the masks handled by **bits**. The default is **8192**. Any bit larger than this number will be truncated.

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

Display help text and exit.

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

Display version and exit.

# [CONVERSION MODE](#CONVERSION_MODE)

One of the following conversion modes can be specified. If not specified, it defaults to **-m**, **--mask**.

**-b**, **--binary**

Print the combined arguments as a binary mask value.

**-g**, **--grouped-mask**

Print the combined arguments as a hexadecimal mask value in 32-bit comma-separated groups.

**-l**, **--list**

Print the combined arguments as a list of bit IDs. Consecutive IDs are compressed to ranges.

**-m**, **--mask**

Print the combined arguments as a hexadecimal mask value (default).

# [EXAMPLES](#EXAMPLES)

```
~$ bits --mask 4,5-8 16,30
0x400101f0
~$ bits --list 0xeec2
1,6,7,9-11,13-15
~$ bits --binary 4,5-8 16,30
0b100_0000_0000_0001_0000_0001_1111_0000
~$ bits --list ,00300000,03000000,30000003
0,1,28,29,56,57,84,85
~$ bits --list 1,2,3,4 ~3-10
1,2
~$ bits --list 1,2,3,4 ^3-10
1,2,5-10
~$ bits --grouped-mask 2,22,74,79
8400,00000000,00400004
~$ bits --width 64 --list 2,22,74,79
2,22
```

# [AUTHORS](#AUTHORS)

Robin Jarry.

# [REPORTING BUGS](#REPORTING_BUGS)

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

# [AVAILABILITY](#AVAILABILITY)

The **bits** 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: bits(1) from util-linux 2.42.4-r0 (Chainguard OS)