The hexdump command is a tool for printing hexadecimal data in Linux. It can output hexadecimal data in the specified format. It is particularly useful. It is out of order to use it with the EEPROM.
Today we will introduce the use of an hexdump command:
First, we prepare a test file for testing. The hexadecimal format is as follows:
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- 00 01 02 03 04 05 06 07 08 09 0a 0b 0C 0d 0e 0f
- 10 11 12 13 14 15 16 17 18 19 1A 1B 1C 1D 1E 1f
- 20 21 22 23 24 25 26 28 29 2a 2B 2C 2D 2E 2f
00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F10 11 12 13 14 15 16 17 18 19 1A 1B 1C 1D 1E 1F20 21 22 23 24 25 26 27 28 29 2A 2B 2C 2D 2E 2F
Option:
-N Length
Only format the first length of the input file
-C Outputs hexadecimal and corresponding characters
Input:
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- Hexdump-N 13-C Test
hexdump -n 13 -C test
Output:
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- 00000000 00 01 02 03 04 05 06 07 08 09 0a 0b 0C | .......... |
- 0000000d
00000000 00 01 02 03 04 05 06 07 08 09 0a 0b 0c |.............|0000000d
-S: Output starting from offset
Input:
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- Hexdump-N 13-C-S 30 test
hexdump -n 13 -C -s 30 test
Output:
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- 2017001e 1E 1f 20 21 22 23 24 25 26 27 28 29 2a | ..! "# $ % & '() * |
- 0000002b
0000001e 1e 1f 20 21 22 23 24 25 26 27 28 29 2a |.. !"#$%&'()*|0000002b
Hexdump advanced usage:
-E specifies the format string, which is contained in a pair of single quotes. The format string is like:
'A/B "format1" "format2 "'
Each format string is composed of three parts, each separated by spaces. The first is a/B, and B indicates that format1 is applied to every B input bytes, a Indicates that format2 format is applied to each input byte of A. Generally, A> B is used, and B can only be 1, 2, and 4. In addition, a can be omitted, and a = 1 If omitted. You can use a string similar to printf in format1 and format2, for example:
% 02d: two decimal places
% 03x: three-digit hexadecimal
% 02o: Two octal workers
% C: Single CharacterAnd so on
There are some special usage:
% _ Ad: Mark the sequence number of the next output byte, in decimal format
% _ Ax: Number of the next output byte, expressed in hexadecimal notation
% _ AO: the serial number of the next output byte, expressed in octal.
% _ P: cannot be replaced.
If you want to display multiple format strings in the same line, you can use multiple-e options
Example 1:Input:
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- Hexdump-e '2014 "% 02x" "|" '-e '2014 "% _ p" "\ n" 'test
hexdump -e '16/1 "%02X " " | "' -e '16/1 "%_p" "\n"' test
Output:
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- 00 01 02 03 04 05 06 07 08 09 0a 0b 0C 0d 0e 0f | ................
- 10 11 12 13 14 15 16 17 18 19 1A 1B 1C 1D 1E 1f | ................
- 20 21 22 23 24 25 26 28 29 2a 2B 2C 2D 2E 2f |! "# $ % & '() * + ,-./
00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F | ................10 11 12 13 14 15 16 17 18 19 1A 1B 1C 1D 1E 1F | ................20 21 22 23 24 25 26 27 28 29 2A 2B 2C 2D 2E 2F | !"#$%&'()*+,-./
Example 2:Input:
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- Hexdump-e '1/1 "0x % 08_ax" '-e '8/1 "% 02x" * "'-e' 8/1" % _ p "" \ n "'test
hexdump -e '1/1 "0x%08_ax "' -e '8/1 "%02X " " * "' -e '8/1 "%_p" "\n"' test
Output:
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- 0x00000000 00 01 02 03 04 05 06 07 *........
- 0x00000008 08 09 0a 0b 0C 0d 0e 0f *........
- 0x00000010 10 11 12 13 14 15 16 17 *........
- 0x00000018 18 19 1A 1B 1C 1D 1E 1f *........
- 0x00000020 20 21 22 23 24 25 26 27 *! "# $ % &'
- 0x00000028 28 29 2a 2B 2C 2D 2E 2f * () * + ,-./
0x00000000 00 01 02 03 04 05 06 07 * ........0x00000008 08 09 0A 0B 0C 0D 0E 0F * ........0x00000010 10 11 12 13 14 15 16 17 * ........0x00000018 18 19 1A 1B 1C 1D 1E 1F * ........0x00000020 20 21 22 23 24 25 26 27 * !"#$%&'0x00000028 28 29 2A 2B 2C 2D 2E 2F * ()*+,-./
Example 3:Input:
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- Hexdump-e '1/1 "% 02_ad #" '-E'/1 "hex = % 02x *"'-E'/1 "dec = % 03d |" '-e' /1 "Oct = % 03o" '-E'/1 "\ _ \ n"'-N 20 test
hexdump -e '1/1 "%02_ad# "' -e '/1 "hex = %02X * "' -e '/1 "dec = %03d | "' -e '/1 "oct = %03o"' -e '/1 " \_\n"' -n 20 test
Output:
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- 00 # hex = 00 * dec = 000 | Oct = 000 _
- 01 # hex = 01 * dec = 001 | Oct = 001 _
- 02 # hex = 02 * dec = 002 | Oct = 002 _
- 03 # hex = 03 * dec = 003 | Oct = 003 _
- 04 # hex = 04 * dec = 004 | Oct = 004 _
- 05 # hex = 05 * dec = 005 | Oct = 005 _
- 06 # hex = 06 * dec = 006 | Oct = 006 _
- 07 # hex = 07 * dec = 007 | Oct = 007 _
- 08 # hex = 08 * dec = 008 | Oct = 010 _
- 09 # hex = 09 * dec = 009 | Oct = 011 _
- 10 # hex = 0a * dec = 010 | Oct = 012 _
- 11 # hex = 0b * dec = 011 | Oct = 013 _
- 12 # hex = 0C * dec = 012 | Oct = 014 _
- 13 # hex = 0d * dec = 013 | Oct = 015 _
- 14 # hex = 0e * dec = 014 | Oct = 016 _
- 15 # hex = 0f * dec = 015 | Oct = 017 _
- 16 # hex = 10 * dec = 016 | Oct = 020 _
- 17 # hex = 11 * dec = 017 | Oct = 021 _
- 18 # hex = 12 * dec = 018 | Oct = 022 _
- 19 # hex = 13 * dec = 019 | Oct = 023 _
