% 2022-12-05
# NAME
hexyl - a command-line hex viewer
# SYNOPSIS
**hexyl** [_OPTIONS_] [_FILE_]
# DESCRIPTION
**hexyl** is a simple hex viewer for the terminal.
It uses a colored output to distinguish different categories of bytes (NULL
bytes, printable ASCII characters, ASCII whitespace characters, other ASCII
characters and non-ASCII).
# POSITIONAL ARGUMENTS
_FILE_
: The file to display.
If no _FILE_ argument is given, read from STDIN.
# OPTIONS
**-n**, **\--length** _N_
: Only read _N_ bytes from the input.
The _N_ argument can also include a unit with a decimal prefix (kB, MB, ..)
or binary prefix (kiB, MiB, ..), or can be specified using a hex number.
Examples:
:
Read the first 64 bytes:
: $ **hexyl \--length=64**
Read the first 4 kibibytes:
: $ **hexyl \--length=4KiB**
Read the first 255 bytes (specified using a hex number):
: $ **hexyl \--length=0xff**
**-c**, **\--bytes** _N_
: An alias for **-n**/**\--length**.
**-l** _N_
: Yet another alias for **-n**/**\--length**.
**-s**, **\--skip** _N_
: Skip the first _N_ bytes of the input.
The _N_ argument can also include a unit (see **\--length** for details).
A negative value is valid and will seek from the end of the file.
**\--block-size** _SIZE_
: Sets the size of the block unit to _SIZE_ (default is 512).
Examples:
:
Sets the block size to 1024 bytes:
: $ **hexyl \--block-size=1024 \--length=5block**
Sets the block size to 4 kilobytes:
: $ **hexyl \--block-size=4kB \--length=2block**
**-v**, **\--no-squeezing**
: Displays all input data.
Otherwise any number of groups of output lines which would be identical to
the preceding group of lines, are replaced with a line comprised of a
single asterisk.
**\--color** _WHEN_
: When to use colors.
The auto-mode only displays colors if the output goes to an interactive
terminal.
Possible values:
: - **always** (default)
- **auto**
- **never**
**\--border** _STYLE_
: Whether to draw a border with Unicode characters, ASCII characters, or none
at all.
Possible values:
: - **unicode** (default)
- **ascii**
- **none**
**-o**, **\--display-offset** _N_
: Add _N_ bytes to the displayed file position.
The _N_ argument can also include a unit (see **\--length** for details).
A negative value is valid and calculates an offset relative to the end of
the file.
**-h**, **\--help**
: Prints help information.
**-V**, **\--version**
: Prints version information.
# ENVIRONMENT VARIABLES
**hexyl** colors can be configured via environment variables. The variables used are as follows:
: - **HEXYL_COLOR_ASCII_PRINTABLE**: Any non-whitespace printable ASCII character
- **HEXYL_COLOR_ASCII_WHITESPACE**: Whitespace such as space or newline (only visible in middle panel with byte values)
- **HEXYL_COLOR_ASCII_OTHER**: Any other ASCII character (< **0x80**) besides null
- **HEXYL_COLOR_NULL**: The null byte (**0x00**)
- **HEXYL_COLOR_NONASCII**: Any non-ASCII byte (> **0x7F**)
- **HEXYL_COLOR_OFFSET**: The lefthand file offset
The colors can be any of the 8 standard terminal colors: **black**, **blue**, **cyan**, **green**, **magenta**, **red**,
**yellow** and **white**. The "bright" variants are also supported (e.g., **bright blue**). Additionally, you can use
the RGB hex format, **#abcdef**. For example, **HEXYL_COLOR_ASCII_PRINTABLE=blue HEXYL_COLOR_ASCII_WHITESPACE="bright green"
HEXYL_COLOR_ASCII_OTHER="#ff7f99"**.
# NOTES
Source repository:
: <https://github.com/sharkdp/hexyl>
# EXAMPLES
Print a given file:
: $ **hexyl small.png**
Print and view a given file in the terminal pager:
: $ **hexyl big.png | less -r**
Print the first 256 bytes of a given special file:
: $ **hexyl -n 256 /dev/urandom**
# AUTHORS
**hexyl** was written by David Peter <mail@david-peter.de>.
# REPORTING BUGS
Bugs can be reported on GitHub at:
: <https://github.com/sharkdp/hexyl/issues>
# COPYRIGHT
**hexyl** is dual-licensed under:
: - Apache License 2.0 (<https://www.apache.org/licenses/LICENSE-2.0>)
- MIT License (<https://opensource.org/licenses/MIT>)
# SEE ALSO
**hexdump**(1), **xxd**(1)
