Examples:
dir | od -c | more
(I would probably rather do: ls -b to see any non-printable characters in filenames).
cat my_file | od -c |more
od my_file |more
Comparison of different outputs:
Show 16 first characters from a binary (/bin/sh) as ASCII characters or backslash escapes (octal):
od -N 16 -c /bin/sh
output:
0000000 177 E L F 001 001 001 \0 \0 \0 \0 \0 \0 \0 \0 \0
Show the same binary as named ASCII characters:
od -N 16 -a /bin/sh
output:
0000000 del E L F soh soh soh nul nul nul nul nul nul nul nul nul
Show the same binary as short hexcadecimals:
od -N 16 -t x1 /bin/sh
output:
0000000 7f 45 4c 46 01 01 01 00 00 00 00 00 00 00 00 00
Show the same binary as octal numbers:
od -N 16 /bin/sh
output:
0000000 042577 043114 000401 000001 000000 000000 000000 000000
wc
(=word count) Print the number of lines, words, and bytes in the file.
Examples:
dir | wc
cat my_file | wc
wc myfile
cksum filename
Compute the CRC (="cyclic redundancy check") for file filename to verify its integrity.
md5sum filename
Compute a md5 checksum (128-bit) for file filename to verify its integrity.
mkpasswd -l 10
Make a hard-to-guess, random password of the length of 10 characters.
sort -f filename
Arrange the lines in filename according to the ascii order. The option -f tells sort to ignore the upper and lower character case. The ascii character set is (see man ascii):
Dec Hex Char Dec Hex Char Dec Hex Char Dec Hex Char
---------------------------------------------------------------------------
0 00 NUL '\0' 32 20 SPACE 64 40 @ 96 60 '
1 01 SOH 33 21 ! 65 41 A 97 61 a
2 02 STX 34 22 " 66 42 B 98 62 b
3 03 ETX 35 23 # 67 43 C 99 63 c
4 04 EOT 36 24 $ 68 44 D 100 64 d
5 05 ENQ 37 25 % 69 45 E 101 65 e
6 06 ACK 38 26 & 70 46 F 102 66 f
7 07 BEL '\a' 39 27 ' 71 47 G 103 67 g
8 08 BS '\b' 40 28 ( 72 48 H 104 68 h
9 09 HT '\t' 41 29 ) 73 49 I 105 69 i
10 0A LF '\n' 42 2A * 74 4A J 106 6A j
11 0B VT '\v' 43 2B + 75 4B K 107 6B k
12 0C FF '\f' 44 2C , 76 4C L 108 6C l
13 0D CR '\r' 45 2D - 77 4D M 109 6D m
14 0E SO 46 2E . 78 4E N 110 6E n
15 0F SI 47 2F / 79 4F O 111 6F o
16 10 DLE 48 30 0 80 50 P 112 70 p
17 11 DC1 49 31 1 81 51 Q 113 71 q
18 12 DC2 50 32 2 82 52 R 114 72 r
19 13 DC3 51 33 3 83 53 S 115 73 s
20 14 DC4 52 34 4 84 54 T 116 74 t
21 15 NAK 53 35 5 85 55 U 117 75 u
22 16 SYN 54 36 6 86 56 V 118 76 v
23 17 ETB 55 37 7 87 57 W 119 77 w
24 18 CAN 56 38 8 88 58 X 120 78 x
25 19 EM 57 39 9 89 59 Y 121 79 y
26 1A SUB 58 3A : 90 5A Z 122 7A z
27 1B ESC
