File Permissions - chmod

Discussion in 'Beginner Tutorials' started by Rob, Jul 9, 2013.

  1. Saptarshi Nag

    Saptarshi Nag Member

    Messages:
    45
    Likes Received:
    29
    Trophy Points:
    18
    the link says it all! :)

  2. DevynCJohnson

    DevynCJohnson Well-Known Member Staff Member Staff Writer

    Messages:
    1,547
    Likes Received:
    1,209
    Trophy Points:
    113
    I hope that helps. Explaining to people how a folder is executable is hard to explain.
    Saptarshi Nag and Haider92 like this.
  3. hindu tadakamalla

    hindu tadakamalla New Member

    Messages:
    1
    Likes Received:
    1
    Trophy Points:
    1
    thank u..u made it very simple for me
    DevynCJohnson likes this.
  4. plotozoidz

    plotozoidz New Member

    Messages:
    4
    Likes Received:
    0
    Trophy Points:
    1
    stat

    If you want a bit more information than ls -l file/directory provides, you can use the command stat. Lets say i have a file called file1.txt:

    Code:
    ls -l file1.txt
    outputs:
    -rw-r--r-- 1 username username 71 Mar 24 20:45 file1.txt

    Code:
    stat file1.txt
    outputs:
    File: `file1.txt'
    Size: 71 Blocks: 24 IO Block: 4096 regular file
    Device: 14h/20d Inode: 6029568 Links: 1
    Access: (0644/-rw-r--r--) Uid: ( 1000/username) Gid: ( 1000/username)
    Access: 2014-03-24 21:37:49.826768784 +0000
    Modify: 2014-03-24 21:50:23.618789336 +0000
    Change: 2014-03-24 21:50:23.618789336 +0000
    Birth: -

    As you can see stat gives more detail, including the numeric 'chmod' value: 0644
    Handy if you want to check the corresponding numeric value permission of a file or directory!
    Last edited: Mar 24, 2014
  5. Arvind Kumar Singh

    Arvind Kumar Singh New Member

    Messages:
    3
    Likes Received:
    1
    Trophy Points:
    1
    Hi,

    I wanted to know if we can check when the permission of a directory got changed in Linux?
    DevynCJohnson likes this.
  6. Saptarshi Nag

    Saptarshi Nag Member

    Messages:
    45
    Likes Received:
    29
    Trophy Points:
    18
    By ls -l directory_name , you can check permission of directory.
    DevynCJohnson likes this.
  7. Arvind Kumar Singh

    Arvind Kumar Singh New Member

    Messages:
    3
    Likes Received:
    1
    Trophy Points:
    1
    Thanks!! but I want to know the time the directory permissions got changed.
  8. Saptarshi Nag

    Saptarshi Nag Member

    Messages:
    45
    Likes Received:
    29
    Trophy Points:
    18
    You can see the bash history with time stamp by the following command
    HISTTIMEFORMAT="%d/%m/%y %T "
    and then type 'history'

    To see your modifications you can use grep.
    That is,
    history | grep directory_name
    Now you can see all the modifications made through terminal.
  9. Arvind Kumar Singh

    Arvind Kumar Singh New Member

    Messages:
    3
    Likes Received:
    1
    Trophy Points:
    1
    Thanks Saptarshi
  10. DevynCJohnson

    DevynCJohnson Well-Known Member Staff Member Staff Writer

    Messages:
    1,547
    Likes Received:
    1,209
    Trophy Points:
    113
    I love your answers. Thanks!
    Saptarshi Nag likes this.
  11. Saptarshi Nag

    Saptarshi Nag Member

    Messages:
    45
    Likes Received:
    29
    Trophy Points:
    18
    You all are welcome :)
  12. Rupam Das

    Rupam Das New Member

    Messages:
    1
    Likes Received:
    0
    Trophy Points:
    1
    I am using Ubuntu and Windows 7 on a same machine. Just install Ubuntu on your Windows OS. You will see dual boot option at the time of startup.

    ps: You can install both OS in same directory :)
  13. sudlin

    sudlin New Member

    Messages:
    4
    Likes Received:
    0
    Trophy Points:
    1
    Hi Rob, really good explanation. I liked it...
  14. cwilson56

    cwilson56 New Member

    Messages:
    2
    Likes Received:
    1
    Trophy Points:
    3
    Thanks for the lesson ... time to practice!!
    DevynCJohnson likes this.
  15. kundai

    kundai New Member

    Messages:
    1
    Likes Received:
    2
    Trophy Points:
    3
    Another fancy but simple way of assigning permission like chmod 777 is
    chmod ugo+rwx filename
    This means all permissions are granted to all.
    where u=user, g=group and 0=others
    Also r=read, w=write and x=execute.

    You can assign individual permisions like;
    chmod u+r filename
    This means only the user is given that read permission to that file/directory.

    If you want to remove a permision you can say
    chmod u-r filename
    This means the user no longer has read permission i.e. "-" removes while "+" adds permission(s).

    In case of directories/folder, if you want the permissions to be recurring use "-R" option then the permissions will apply to everything in that directorye.g
    chmod -R ugo+rwx directory_name
    Sahadat Khan and DevynCJohnson like this.
  16. cwilson56

    cwilson56 New Member

    Messages:
    2
    Likes Received:
    1
    Trophy Points:
    3
    Kundal, thank you for the instructions. These are simple and explicit instructions.
  17. cuellarsd

    cuellarsd New Member

    Messages:
    5
    Likes Received:
    1
    Trophy Points:
    1
    thanks, excellent info for newbies, very concise
    DevynCJohnson likes this.
  18. MikeR

    MikeR New Member

    Messages:
    1
    Likes Received:
    1
    Trophy Points:
    1
    Excellent explanation of chmod...this helped me a lot: specifically I thought it was decimal.
    DevynCJohnson likes this.
  19. Pinguin

    Pinguin New Member

    Messages:
    1
    Likes Received:
    0
    Trophy Points:
    1
    hi everybody, I have a large CSV file with lots of literature references. ‘;’ is used as the delimiter. Each row contains 4 fields:
    I want to use linux commands to get out names of all the authors of the paper and year of the publication (written within the parentheses)..
    can anyone help please, thank you in advance.
  20. MuthuV

    MuthuV New Member

    Messages:
    1
    Likes Received:
    0
    Trophy Points:
    1
    Its a great post and would help beginners in lots !!!!!!!!!!!!!!

Share This Page