NAME
hexdump - display file contents in hexadecimal, decimal, octal, or asciiDESCRIPTION
The hexdump utility is a filter which displays the specified files, or standard input if no files are specified, in a user-specified format.OPTIONS
Below, the length and offset arguments may be followed by the multiplicative suffixes KiB (=1024), MiB (=1024*1024), and so on for GiB, TiB, PiB, EiB, ZiB and YiB (the "iB" is optional, e.g., "K" has the same meaning as "KiB"), or the suffixes KB (=1000), MB (=1000*1000), and so on for GB, TB, PB, EB, ZB and YB.
One-byte octal display. Display the
input offset in hexadecimal, followed by sixteen space-separated,
three-column, zero-filled bytes of input data, in octal, per line.
One-byte character display. Display the
input offset in hexadecimal, followed by sixteen space-separated,
three-column, space-filled characters of input data per line.
Canonical hex+ASCII display. Display
the input offset in hexadecimal, followed by sixteen space-separated,
two-column, hexadecimal bytes, followed by the same sixteen bytes in
%_p format enclosed in | characters. Invoking the program as
hd implies this option.
Two-byte decimal display. Display the
input offset in hexadecimal, followed by eight space-separated, five-column,
zero-filled, two-byte units of input data, in unsigned decimal, per
line.
Specify a format string to be used for
displaying data.
Specify a file that contains one or more
newline-separated format strings. Empty lines and lines whose first non-blank
character is a hash mark (#) are ignored.
Accept color units for the output. The
optional argument when can be auto, never or
always. If the when argument is omitted, it defaults to
auto. The colors can be disabled; for the current built-in default see
the --help output. See also the Colors subsection and the
COLORS section below.
Interpret only length bytes of
input.
Two-byte octal display. Display the
input offset in hexadecimal, followed by eight space-separated, six-column,
zero-filled, two-byte quantities of input data, in octal, per line.
Skip offset bytes from the beginning of
the input.
The -v option causes hexdump to
display all input data. Without the -v option, any number of groups of
output lines which would be identical to the immediately preceding group of
output lines (except for the input offsets), are replaced with a line
comprised of a single asterisk.
Two-byte hexadecimal display. Display
the input offset in hexadecimal, followed by eight space-separated,
four-column, zero-filled, two-byte quantities of input data, in hexadecimal,
per line.
Display help text and exit.
Print version and exit.
FORMATS
A format string contains any number of format units, separated by whitespace. A format unit contains up to three items: an iteration count, a byte count, and a format.An asterisk (*) may not be used as a field
width or precision.
A byte count or field precision is
required for each s conversion character (unlike the fprintf(3)
default which prints the entire string if the precision is unspecified).
The conversion characters h, l,
n, p, and q are not supported.
The single character escape sequences
described in the C standard are supported:
NULL | \0 |
<alert character> | \a |
<backspace> | \b |
<form-feed> | \f |
<newline> | \n |
<carriage return> | \r |
<tab> | \t |
<vertical tab> | \v |
Conversion strings
The hexdump utility also supports the following additional conversion strings.Display the input offset, cumulative across
input files, of the next byte to be displayed. The appended characters
d, o, and x specify the display base as decimal, octal or
hexadecimal respectively.
Almost identical to the _a conversion
string except that it is only performed once, when all of the input data has
been processed.
Output characters in the default character
set. Non-printing characters are displayed in three-character, zero-padded
octal, except for those representable by standard escape notation (see above),
which are displayed as two-character strings.
Output characters in the default character
set. Non-printing characters are displayed as a single ' .'.
Output US ASCII characters, with the exception
that control characters are displayed using the following, lower-case, names.
Characters greater than 0xff, hexadecimal, are displayed as hexadecimal
strings.
000 nul | 001 soh | 002 stx | 003 etx | 004 eot | 005 enq |
006 ack | 007 bel | 008 bs | 009 ht | 00A lf | 00B vt |
00C ff | 00D cr | 00E so | 00F si | 010 dle | 011 dc1 |
012 dc2 | 013 dc3 | 014 dc4 | 015 nak | 016 syn | 017 etb |
018 can | 019 em | 01A sub | 01B esc | 01C fs | 01D gs |
01E rs | 01F us | 0FF del |
Colors
When put at the end of a format specifier, hexdump highlights the respective string with the color specified. Conditions, if present, are evaluated prior to highlighting.Negate the condition. Please note that it only
makes sense to negate a unit if both a value/string and an offset are
specified. In that case the respective output string will be highlighted if
and only if the value/string does not match the one at the offset.
One of the 8 basic shell colors.
A value to be matched specified in
hexadecimal, or octal base, or as a string. Please note that the usual C
escape sequences are not interpreted by hexdump inside the
color_units.
An offset or an offset range at which to check
for a match. Please note that lone OFFSET_START uses the same value as END
offset.
Counters
The default and supported byte counts for the conversion characters are as follows:One byte counts only.
Four byte default, one, two and four byte
counts supported.
Eight byte default, four byte counts
supported.
EXIT STATUS
hexdump exits 0 on success and > 0 if an error occurred.CONFORMING TO
The hexdump utility is expected to be IEEE Std 1003.2 ("POSIX.2") compatible.EXAMPLES
Display the input in perusal format:"%06.6_ao " 12/1 "%3_u " "\t" "%_p " "\n"
"%07.7_Ax\n" "%07.7_ax " 8/2 "%04x " "\n"
"%07.7_Ax_L[cyan]\n" "%07.7_ax_L[cyan] " 8/2 " %04x_L[green:0xAA55@510-511,!red:0xAA55@510-511] " "\n"
COLORS
The output colorization is implemented by terminal-colors.d(5) functionality. Implicit coloring can be disabled by an empty fileREPORTING BUGS
For bug reports, use the issue tracker at <https://github.com/util-linux/util-linux/issues>.AVAILABILITY
The hexdump 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/>.2022-05-11 | util-linux 2.38.1 |