Skip to main content

UBUNTU BASIC COMMANDS

ubuntu.png
UBUNTU BASIC COMMANDS:

1. echoing data:
        syntax: echo name(variable).
            returns the value of the variable

2. help:
        syntax: man command
            this will give us the syntax and options available in UNIX.

3. searching a particular file:
        syntax: find -name "tools.jar" print 2>/dev/null
            searches for the file "tools.jar" based upon the name and if not found returns error msg 2 and so we redirect it using ">" to the /dev/null directory.

4. pipe symbol:
        syntax: process1 | process 2
            the pipe symbol "|" is used to provide the output of one process as the input to the other process
            eg. ls -l | wc : here 'ls -l' returns the list of files within the directory and we provide this as the input to the second process 'wc' (wordcount). thus returning the word count of the list of files .

5. tee:
        syntax: tee option filename 
                 read from standard input and write to standard output and files

6. source:
        syntax: source folder_name    
                to get the required created variables from the specified folder.

7.  ls command to list the files in the directory.
      
8. cat command to view the existing file.
        Syntax: cat  /etc/list.txt

9. vi command to edit a file
        Syntax: vi filename

10. Nano: Another editor to edit files.

11. mv command: to rename/move files from one location to another.
            mv oldfile newfile

12. rm command:removing files (deleting)
        syntax:  rm filename
     rmdir : removing directories
        syntax: rmdir directory

13. chmod : change file access permissions.
        eg: chmod 755 file.txt
        has a 10 digit binary code.
        400 read by owner

        040 read by group

        004 read by anybody (other)

        200 write by owner

        020 write by group

        002 write by anybody

        100 execute by owner

        010 execute by group

        001 execute by anybody


14. chown - change file owner and group

    Usage

    chown [OPTION] OWNER[:[GROUP]] FILE

    chown [OPTION] :GROUP FILE

    chown [OPTION] --reference=RFILE FILE



15. cp - Copy files

        syntax: cp  myfile yourfile

16  cd - to navigate into files
        syntax: cd foldername/foldername/file

Comments

Popular posts from this blog

My 10 years in Application Development

It's been around 10 years since I started programming. May be a bit more, if I have to include my first attempts at C programming in school. But it would be a grave insult to call remembering ten lines of code and just replicating it to put a star on the screen. I also did a course on Visual basic, but it was more gimmicks that Application development. But it was truly in the year 2007 when I started my Master in Computer Applications that I found a new flare for developing applications. 
I was very late to computers in general and even when I joined my Masters, computers were not really accessible to me. But when I joined my Masters where one is actually expected to hone the skills which they already have, but in case it was were I was learning the skills, initially it was very difficult. I was not sure what computers had for me nor I had a natural flair for programming. But the thing about computers that attracted me was the visual medium it gave. Initially it was just a door t…

Changing Timezone in Postgresql, Ubuntu

Timezone and locale are integral concepts that one should be aware of when implementing a System. For example. if you create a database in PostgreSql, it will use the default System settings for the database. Lets say you have a server in UK and your client is US. If the client tries to retrieve the current date or time, it is going to show the UK time and not the US one.
Today I encountered a different issue in our client place where the Ubuntu timezone and PostgreSql timezone were showing a incorrect values. Instead of Indian Standard Time (IST) it was showing Pacific Daylight Time(PDT). These are the steps that I followed to change the timezone to IST in PostgreSql and Ubuntu.
Changing timezone in Ubuntu:
sudo dpkg-reconfigure tzdataYou will be prompted to choose the continent and then the area. Provided screen shots where we configure the location.
Use TAB key to navigate to the OK button and then press Enter.

The changes will get reflected immediately. To check it you can open a n…

Dissecting Openbravo 3.0 UI Architecture

Having been worked on Openbravo 3.0 UI for more than a year now (right from RC1) , Openbravo has leaped ahead of most contemporary ERP's in terms of UX design and usability. And a part of the credit has to go to the community too as they were actively involved in finalizing the UX and also involved enthusiastically in tested out the RC versions and providing their feedback.

In this post, I have tried to draw limelight on the basic UI components that are being used in Openbravo and their corresponding smartclient components. This is just to provide a very high level idea on how the entire architecture is coupled together. I have tried to use a single screen shot of Openbravo interface and tried to map the base components here.

The hierarchy can be visualized in simple terms as follows:

Exhaustive information on these components are provided in the Openbravo Wiki here.

Most of these components are defined and managed from individual files (or code) thereby making it really easy to …