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hexdump command in Linux with Examples
Name
hexdump, hd - ASCII, decimal, hexadecimal, octal dump
Synopsis
hexdump [-bcCdovx] [-e format_string] [-f format_file] [-n length] [-s skip] file ... hd [-bcdovx] [-e format_string] [-f format_file] [-n length] [-s skip] file ...
Description
The hexdump utility is a filter which displays the specified files in a user specified format. In case no files are specified, it reads input from standard input.
Options
The options for hexdump or the hd commands are:
-b One-byte octal display. Displays the input offset (address) of data in hexadecimal format. It is followed by sixteen space-separated, three column, zero-filled, bytes of input data, in octal, per line. -c 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. -C 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. Calling the command hd implies this option. -d 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. -e format_string Specify a format string to be used for displaying data. -f format_file 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. -n length Interpret only length bytes of input. -o 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. -s offset Skip offset bytes from the beginning of the input. By default, offset is interpreted as a decimal number. With a leading 0x or 0X, offset is interpreted as a hexadecimal number, otherwise, with a leading 0, offset is interpreted as an octal number. Appending the character b, k, or m to offset causes it to be interpreted as a multiple of 512, 1024, or 1048576, respectively. -v Cause 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. -x 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. For each input file, hexdump sequentially copies the input to standard output, transforming the data according to the format strings specified by the -e and -f options, in the order that they were specified.
Examples
Using the -b option will display the input offset in hexadecimal format. This output format is also called One-byte-octal display format. The input offset is followed by sixteen space separated, three-column, zero-filled bytes of input data in octal representation per line.
$ hexdump -b test.txt 0000000 163 160 145 143 151 146 171 040 141 040 146 151 154 145 040 164 0000010 150 141 164 040 143 157 156 164 141 151 156 163 040 157 156 145 0000020 040 157 162 040 155 157 162 145 040 156 145 167 154 151 156 145 0000030 012 163 145 160 141 162 141 164 145 144 040 142 171 040 157 156 0000040 145 040 157 162 040 155 157 162 145 040 156 145 167 040 154 151 0000050 156 145 163 056 012 154 151 156 145 163 040 167 150 157 163 145 0000060 040 146 151 162 163 164 040 156 157 156 055 142 154 141 156 153 0000070 040 143 150 141 162 141 143 164 145 162 040 151 163 040 141 040 0000080 150 141 163 150 040 155 141 162 153 040 050 043 051 040 141 162 0000090 145 040 151 147 156 157 162 145 144 056 012 012 000009c
Using the -c option will display the data in character ascii format. The input offset would be shown in hexadecimal format. This output format is also called One-byte-character display. The input offset is followed by sixteen space separated, three-column, space-filled characters of input data per line.
$ hexdump -c test.txt 0000000 s p e c i f y a f i l e t 0000010 h a t c o n t a i n s o n e 0000020 o r m o r e n e w l i n e 0000030 \n s e p a r a t e d b y o n 0000040 e o r m o r e n e w l i 0000050 n e s . \n l i n e s w h o s e 0000060 f i r s t n o n - b l a n k 0000070 c h a r a c t e r i s a 0000080 h a s h m a r k ( # ) a r 0000090 e i g n o r e d . \n \n 000009c
Using the -C option will display the data in ASCII+hex format, also known as Canonical hex+ASCII display. This displays the input offset in hexadecimal format. The input offset is followed by sixteen space-separated, two column, hexadecimal bytes, along with the same sixteen bytes in %_p format enclosed in ``|'' characters. Here is working example of this command option.
$ hexdump -C test.txt 00000000 73 70 65 63 69 66 79 20 61 20 66 69 6c 65 20 74 |specify a file t| 00000010 68 61 74 20 63 6f 6e 74 61 69 6e 73 20 6f 6e 65 |hat contains one| 00000020 20 6f 72 20 6d 6f 72 65 20 6e 65 77 6c 69 6e 65 | or more newline| 00000030 0a 73 65 70 61 72 61 74 65 64 20 62 79 20 6f 6e |.separated by on| 00000040 65 20 6f 72 20 6d 6f 72 65 20 6e 65 77 20 6c 69 |e or more new li| 00000050 6e 65 73 2e 0a 6c 69 6e 65 73 20 77 68 6f 73 65 |nes..lines whose| 00000060 20 66 69 72 73 74 20 6e 6f 6e 2d 62 6c 61 6e 6b | first non-blank| 00000070 20 63 68 61 72 61 63 74 65 72 20 69 73 20 61 20 | character is a | 00000080 68 61 73 68 20 6d 61 72 6b 20 28 23 29 20 61 72 |hash mark (#) ar| 00000090 65 20 69 67 6e 6f 72 65 64 2e 0a 0a |e ignored...| 0000009c $
Using the -o option will 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. This format is also called two-byte octal display.
$ hexdump -o test.txt 0000000 070163 061545 063151 020171 020141 064546 062554 072040 0000010 060550 020164 067543 072156 064541 071556 067440 062556 0000020 067440 020162 067555 062562 067040 073545 064554 062556 0000030 071412 070145 071141 072141 062145 061040 020171 067157 0000040 020145 071157 066440 071157 020145 062556 020167 064554 0000050 062556 027163 066012 067151 071545 073440 067550 062563 0000060 063040 071151 072163 067040 067157 061055 060554 065556 0000070 061440 060550 060562 072143 071145 064440 020163 020141 0000080 060550 064163 066440 071141 020153 021450 020051 071141 0000090 020145 063551 067556 062562 027144 005012 000009c $
Using the -n option will display only 'n' length bytes of input. The below command with -n option only shows first 30 bytes of the input data.
$ hexdump -n 30 -C test.txt 00000000 73 70 65 63 69 66 79 20 61 20 66 69 6c 65 20 74 |specify a file t| 00000010 68 61 74 20 63 6f 6e 74 61 69 6e 73 20 6f |hat contains o| 0000001e $
Using the -s option will skip first 'n' bytes of the input and display the rest of the data.
$ hexdump -s 30 -C test.txt 0000001e 6e 65 20 6f 72 20 6d 6f 72 65 20 6e 65 77 6c 69 |ne or more newli| 0000002e 6e 65 0a 73 65 70 61 72 61 74 65 64 20 62 79 20 |ne.separated by | 0000003e 6f 6e 65 20 6f 72 20 6d 6f 72 65 20 6e 65 77 20 |one or more new | 0000004e 6c 69 6e 65 73 2e 0a 6c 69 6e 65 73 20 77 68 6f |lines..lines who| 0000005e 73 65 20 66 69 72 73 74 20 6e 6f 6e 2d 62 6c 61 |se first non-bla| 0000006e 6e 6b 20 63 68 61 72 61 63 74 65 72 20 69 73 20 |nk character is | 0000007e 61 20 68 61 73 68 20 6d 61 72 6b 20 28 23 29 20 |a hash mark (#) | 0000008e 61 72 65 20 69 67 6e 6f 72 65 64 2e 0a 0a |are ignored...| 0000009c $
Using the -e option to specify a format string to be used for displaying data. Like one hex byte per line.
$ echo hello |hexdump -v -e '/1 "%02X \n"' 68 65 6C 6C 6F 0A $