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Chapter 6 Basic Directory and File Management. Command Line Control Characters Control-s - Stops screen output - rarely used Control-q - Resumes screen.

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Presentation on theme: "Chapter 6 Basic Directory and File Management. Command Line Control Characters Control-s - Stops screen output - rarely used Control-q - Resumes screen."— Presentation transcript:

1 Chapter 6 Basic Directory and File Management

2 Command Line Control Characters Control-s - Stops screen output - rarely used Control-q - Resumes screen output stopped by Control-s - also rare Control-c - Interrupts current activity - frequently used to abort processes or long display outputs Control-d - end-of-file or exit. If stuck, try Control-c or Control-d Control-u - Erases the entire command line - mistyped passwords Control-w - Erases the last word on the command line

3 file and strings Commands Text – ASCII or English text, commands text, and executable shell scripts; can be read using the cat or more commands and edited using vi editor Data – created by an application; only way to read is to open the file with its app Strings command - prints out readable characters from an executable or binary file; used by programmers Executable or Binary – indicates that the file is a command or program; strings command will print out readable characters

4 cat more head tail Commands cat (short for concatenate) command displays the contents of a text file on the screen cat flashes through the entire file rapidly without pausing stop & start the scrolling with the Control-s and Control-q keys more command displays the contents of a text file one screen at a time --More--(n%) man pages output are in more format -scrolling controls head command displays the first n lines first 10 lines are displayed by default if the -n option is omitted. tail command displays the last n lines of a file last 10 lines are displayed by default if the -n option is omitted. allows you to check the end result of the backup without looking at the whole file +n option allows you to start displaying lines from a specific point in a file

5 wc and diff Commands wc (word count) command displays line, word, byte or character counts for a text file without options will give a line, word, and byte count of the contents of the file OptionFunction -lCounts lines -wCounts words -cCounts bytes -mCounts characters diff (difference) command compares two text files and finds differences Command Format:$ diff [option] file1 file2 –i option ignores the case of the letters –c option performs a detailed comparison and produces a listing of differences with three lines of context

6 diff Output

7 Naming Conventions

8 Creating & Removing Files & Directories touch - either creates one or more files with zero bytes if none exists; or updates date/time stamp if file already exists mkdir - creates directories or folders must have the appropriate permissions to create a directory –p (parent) option creates parent directories while creating lower level directories, including all the directories in a pathname rm - removes a single file or multiple files specify their names or use wildcard metacharacters (*) (?) files that are deleted are permanent and cannot be recovered! rm -i (interactive) - prompts the user before removing files - highly recommended rm –r (recursive) - removes directories removes the directory including all subdirectories and files in it! rm -ri (or rm -ir) removes directories interactively

9 CDE File Manager accessed from the Front Panel or by right clicking on the desktop most of the same tasks that are available at the command line benefit - can undelete can NOT compare files as with diff command

10 Lab 6.1.6 – File Information Commands Lab 6.1.10 – Basic Command Line File Management Lab 6.2.6 – Basic CDE File Manager chapter 6 assessment Labs/Assessment

11 Chap 6 Exercise 1. Create a new file called junk1; then verify; how many bytes?

12 Chap 6 Exercise 1. Create a new junk file; then verify; how many bytes? $ touch junk1 $ ls -l junk1

13 Chap 6 Exercise 2. Make directory called junkdir; then verify

14 Chap 6 Exercise 2. Make a directory called junkdir; then verify $ mkdir junkdir $ ls -ld junkdir or $ ls -l

15 Chap 6 Exercise 3. Remove that junk file and that junk directory

16 Chap 6 Exercise 3. Remove that junk file and that junk directory $ rm -i junk1 $ rm -ir junkdir

17


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