Changes between Version 6 and Version 7 of ubuntuinstall

Timestamp:

Nov 17, 2016, 7:41:04 AM (8 years ago)

Author:

admin

Comment:

--

ubuntuinstall

@@ -359 +359 @@
 }}}
 
+=== Working with Files === 
+
+Files on Linux (or any Unix) are case sensitive. This means that FILE1 is different from file1, and /etc/hosts is different from /etc/Hosts (the latter one does not exist on a typical Linux computer). In Linux everything is considered as a file even a directory is a special kind of file. A small overview of some basic and important file handling commands
+
+ - '''file''': The file utility determines the file type. Linux does not use extensions to determine the file type. The command line does not care whether a file ends in .txt or .pdf. As a system administrator, you should use the file command to determine the file type.
+ - '''cp''': To copy a file, use cp with a source and a target argument.
+  * '''cp -r''': To copy complete directories, use cp -r (the -r option forces recursive copying of all files in all subdirectories). 
+  * '''cp -i''': To prevent cp from overwriting existing files, use the -i (for interactive) option.
+ - '''mv''': Use to rename a file or to move the file to another directory.
+ - '''rm''': Use to remove files
+  *'''rm -i''':To prevent yourself from accidentally removing a file.
+  *'''rm -rf''':'''rm -r''' will not remove non-empty directories. However rm accepts several options that will allow you to remove any directory. The rm -rf  will erase anything
+'''Extremely dangerous Command''' 
+{{{
+When you are logged on as root, be very careful with rm -rf (the f means force and the r means recursive) since being root implies 
+that permissions don't apply to you. You can literally erase your entire file system by accident.
+}}}
+ - '''less''':The less command is useful for displaying files that take up more than one screen
+ - '''head/tail''':You can use head to display the first ten lines of a file. and tail to display the last ten lines of a file. you can use both commands with '''-n''' and specify the number of lines
+ - '''cat''':The cat command is one of the most universal tools, yet all it does is copy standard input to standard output.
+
+=== Exercise ===
+
+ -  Create numbers.txt (Containing ten lines of numbers one to ten)file with cat command.
+{{{
+$ cat > numbers.txt 
+}}}
+Add the lines with enter key at the end. After inserting all the lines press Ctrl + D
+{{{
+one
+two
+. .
+ten
+}}}
+ - View the file you created using less and cat
+'''cat'''
+{{{
+$ cat numbers.txt 
+one
+two
+three
+four
+five
+six
+seven
+eight
+nine
+ten
+}}}
+'''less'''
+{{{
+$ less numbers.txt 
+}}}
+Press '''q''' to exit from less
+ - View first four lines and last four lines using head and tail commands
+{{{
+$ head -n 4 numbers.txt 
+one
+two
+three
+four
+$ tail -n 4 numbers.txt 
+seven
+eight
+nine
+ten
+}}}
+
+ - Create another file numbers2.txt(with lines contain eleven to fifteen)
+{{{
+$ cat numbers2.txt 
+eleven
+twevelve
+thirteen
+fourteen
+fifteen
+}}}
+ - Combine numbers.txt and numbers2.txt and create numbers3.txt. and view the file.
+{{{
+$ cat numbers.txt numbers2.txt > numbers3.txt
+$ cat numbers3.txt 
+one
+two
+three
+four
+five
+six
+seven
+eight
+nine
+ten
+eleven
+twevelve
+thirteen
+fourteen
+fifteen
+}}}
+ - Check the file format of the newly created file
+{{{
+$ file numbers3.txt 
+numbers3.txt: ASCII text
+}}}
+
+ - Copy all the created files to the test directory. and verify
+{{{
+$ cp numbers.txt numbers2.txt numbers3.txt test/
+$ cd test
+$ ls
+numbers2.txt  numbers3.txt  numbers.txt  one
+}}}
+
+ - Make a copy of test directory as newtest and rename it to numbers
+{{{
+$ cp -r test/ newtest
+$ mv newtest/ numbers
+}}}
+
+ - Delete the test directory
+{{{
+$ rm -rf test
+}}}
+
+
 === Setting UP IP Addresses ===