0x02. Shell, I/O Redirections and filters

0-hello_world : a script that prints “Hello, World”, followed by a new line to the standard output.

1-confused_smiley : a script that displays a confused smiley "(Ôo)'.

2-hellofile : Display the content of the /etc/passwd file.

3-twofiles : Display the content of /etc/passwd and /etc/hosts

4-lastlines : Display the last 10 lines of /etc/passwd

5-firstlines : Display the first 10 lines of /etc/passwd

6-third_line : a script that displays the third line of the file iacta.

7-file : a shell script that creates a file named exactly *'"Best School"'*$?*****:) containing the text Best School ending by a new line.

8-cwd_state : a script that writes into the file ls_cwd_content the result of the command ls -la. If the file ls_cwd_content already exists, it should be overwritten. If the file ls_cwd_content does not exist, create it.

9-duplicate_last_line : a script that duplicates the last line of the file iacta

10-no_more_js : a script that deletes all the regular files (not the directories) with a .js extension that are present in the current directory and all its subfolders.

11-directories : a script that counts the number of directories and sub-directories in the current directory.

12-newest_files : a script that displays the 10 newest files in the current directory.

13-unique : a script that takes a list of words as input and prints only words that appear exactly once.

14-findthatword : Display lines containing the pattern “root” from the file /etc/passwd

15-countthatword : Display the number of lines that contain the pattern “bin” in the file

16-whatsnext : Display lines containing the pattern “root” and 3 lines after them in the file /etc/passwd.

17-hidethisword : Display all the lines in the file /etc/passwd that do not contain the pattern “bin”.

18-letteronly : Display all lines of the file /etc/ssh/sshd_config starting with a letter.

19-AZ : Replace all characters A and c from input to Z and e respectively.