BITS(1) User Commands BITS(1)

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

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

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

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.

-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.

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).

~$ 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

Robin Jarry.

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

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/.

2026-04-01 util-linux 2.42