Using Linux Commands(2)

1. Using Linux Commands(2) Lab 5

2. Creating files and directories • Use the command mkdir to create a new directory to the current working directory. • $ mkdirdirectoryName

3. Creating files and directories • Go to your home directory. Type cd. • Make sure that you got to your home directory, type pwd • Create a new directory called test in your home directory: • Check the permissions of the directory by typing: • Suppose that you want to prevent everyone else from using or viewing the files in this directory: • Make the test directory your current directory :

4. Creating files and directories • To create a directory(test) in the Desktop, we have two ways: • mkdir /home/chris/Desktop/test • cd /home/chris/Desktopmkdir test • NOTE: • The -d option tells ls not to list the contents of the test directory; just show us the listing for the directory itself.

5. Moving, copying, and deleting files

6. Moving, copying, and deleting files *  remove all files in the current directory

7. Create empty files • To create an empty file in the current directory use the command touch • $ touch file1 file2 file3 Using file-matching metacharacters • Metacharacters help to match one or more files without typing each filename completely. • * This matches any number of characters(zero or more characters). • ? This matches any one(single) character. • […] This matches any one of the characters between the brackets, which can include a dash-separated rang of letters or numbers.

8. Using file-matching metacharactersThis matches any number of characters *

9. Using file-matching metacharactersThis matches any one(single) character?

10. Using file-matching metacharactersThis matches any one of the characters between the brackets […]

11. Using file-redirection metacharacters • < Direct the contents of a file to the command • > Direct the output of a command to a file, overwriting any existing file • >> Direct the output of a command to a file, adding the output to the end of • existing file

12. echo Command • Use echo command to display text or value of variable. echo [options] [string, variables...]

13. Quotes • "Double Quotes“ • variables and command substitution(except \and $). • 'Single quotes‘ • protects everything enclosed between two single quote marks. • It is used to turn off the special meaning of all characters ( NOsubstitution of variables and commands). • `Back quote` • Used with commands only. • To execute command.

15. echo Command • Options-nDo not output the trailing new line.-eEnable interpretation of the following backslash escaped characters in the strings: \a alert (bell)\b backspace\n new line\t horizontal tab

16. Examples of quoting special characters

17. Sort command • Sort the lines of text files. $ sort fileName • by default it will sort in normal order(alphabetical 0-9 A-Z ). • Options • -rReverse normal order(reverse alphabetical Z-A 9-0).-nSort in numeric order(Sorts by the beginning of the number at the beginning of the line.)-nrSort in reverse numeric order • Note that this command does not sort the actual file, it just displays the sorted output on your terminal.

18. Sequential commands • To run a sequence of commands type several commands on the same command line and separating them with semicolons(;)

19. References http://www.podgrid.org/linux-bible/linux-bible-page109.html