Basic command line of ubuntu/linux operating system
1. to show list file:
$ ls -lsr
2. to swap directories to the previous working directory
$ cd -
3. to delete all files
$ rm *
4. to delete every instance of a matching filename pattern from the current directory
$ rm –rf filename.*
5. to display the file contents directly on the screen
$ more filename $ less filename
6. to use ls –l to display a list of files but it keeps scrolling off the screen, you can pipe the output from the ls –l command into the input of the more command by using the | character.
$ ls -l | more
7. to save the output of that list directly into a file.
$ ls -l > output.txt
8. cat command to display the contents of that file, pipe that into the grep command and then redirect that output into a separate file:
$ cat nc6build.sh | grep sh > output.txt
9. to show recently used command
$ history
10. to loop through a set of filenames and perform an action on each one, you can use the for command to loop through a set of files.
$ for f in *.txt;do echo $f;done
11. to find all files with .txt in the name that were modified in the last 5 days.
$ find . –name "*.txt" –mtime 5
12. to quickly find text within files, even searching through subdirectories.
$ grep -ir "seraching text" *
13. to quickly rename files using a regular expression pattern. For instance, if you wanted to rename all files containing foo to contain bar instead, you could use a command like this one
$ rename –v 's/foo/bar/g' *
14. to see a list of system processes
$ ps aux
15. to kill the running process
kill
16. unpack the archive/zip in any directory
tar xfz eclipse-jee-ganymede-SR1-linux-gtk.tar.gz
17. point a folder directory
ln -s /usr/home/palash/douments documents
