1 $ cd ~/learncli
 2 $ ls -F
 3 cat.txt  copydir/  fox.txt  movedir/  right/  toolong.txt
 4 
 5 $ cat fox.txt cat.txt
 6 $ cat fox.txt cat.txt > foxcat.txt
 7 $ cat cat.txt fox.txt > catfox.txt
 8 $ ls
 9 $ cat foxcat.txt
10 $ cat catfox.txt
11 
12 $ cat > colors.txt
13 Red
14 Green
15 Blue
16 ^D  <-- บรรทัดนี้หมายความว่าให้กดปุ่ม Ctrl+d นะครับ
17 
18 $ cat colors.txt
19 
20 $ cat > colors.txt
21 Black
22 White
23 Yellow
24 ^D
25 
26 $ cat colors.txt
27 
28 $ cat >> colors.txt
29 Red
30 Green
31 Blue
32 ^D
33 
34 $ cat colors.txt
35 
36 $ cat >> colors.txt
37 Pink
38 Purple
39 ^D
40 
41 $ cat colors.txt
42 
43 $ cat < colors.txt
44 $ more < colors.txt
45 $ less < colors.txt
46 
47 $ sort < colors.txt
48 $ sort < colors.txt > sortcolors.txt
49 $ cat sortcolors.txt