How to delete a write protected file

Posted on in Categories FAQ, Howto, Tips last updated August 25, 2006

Reader Ashish asks “How to delete write protected file under Linux…”

Under Linux (and other Unixsh oses) following criteria should matched before deleting a file:

Criteria # 1

To delete or remove a file you need to be owner of a file. Use ls -l command to verify your ownership:
$ ls -l filename

If you have sufficient rights, you can remove a file. Otherwise, become a superuser to remove a file.

Criteria # 2

In addition, you must have a write access to on a directory that allows you to remove or add new files. Again us ls -l or ls -ld command to get write ownership of directory.
$ ls -ld dirname

If you have sufficient rights, you can remove a file. Otherwise, become a superuser to remove a file. Use chown / chmod commands to setup permission OR run rm command as root user:
# su -
# rm -f file.txt

Criteria # 3

Make sure file is not protected using extended file system ‘i‘ attribute. A file with the ‘i‘ attribute cannot be modified, it cannot be deleted or renamed, no link can be created to this file and no data can be written to the file. Only root can add or remove ‘i‘ attribute. Use lsatter command to verify that file is not write protected using extended ‘i‘ attribute:
$ lsattr file.txt

Output:

----i------------ file.txt

Above output indicates that file.txt has i attribute set on it. Become a superuser and follow the instruction mentioned here to remove a write protected file:
# chattr -i file.txt
# rm -f file.txt

Posted by: Vivek Gite

The author is the creator of nixCraft and a seasoned sysadmin and a trainer for the Linux operating system/Unix shell scripting. He has worked with global clients and in various industries, including IT, education, defense and space research, and the nonprofit sector. Follow him on Twitter, Facebook, Google+.

23 comment

  1. can u use that
    in deepfreeze
    without knowing the password

    can u delete deepfreeze just like that
    it is write protected
    and then theres password when you need to disable

    is there any other method deleting write protected file

  2. On the Mini SD adapter, there is a lock tap you push down usually when you put your mini SD card in to it, then into the USB adapter. To turn off the write protection on your mini SD, simply do not lock your mini SD in its adapter.

  3. ok i had the same problem i downloaded a patch from a peer 2 peer site and it was’nt wot i wanted
    and tried to delete it but it said it was write portected so i just tried to just stuff it up as much as i could just playin round with its properties and here is wot i came up with GO INTO PROPERTIES OF THE FILE THEN CLICK ADVANCED MAKE SURE THE BOXES THAT SAY…… FILE IS READY FOR ARCIVING,……FOR FAST SEARCHING ALOW INDEXING SERVICE TO INDEX THIS FILE AND…. COMPRES FILES TO SAVE DISC SPACE .. ARE ALL UNCHECKED THEN CLICK OK THEN GO TO THE PART THAT SAYS ….READ ONLY AND TICK IT THEN PRESS OK IT SHOULD EXIT IF ANY ERRORS COME UP THEN JUST CLICK OK THEN TRY DELETEING IT IT WORKED 4 MEHOPE IT DOES 4 ALL U PPL 2 NOTE:I DONE THIS WITH A FILE NOT A FOLDER SO DONT EXPECT IT TO WORK ON FOLDRES I DONT EVEN KNOW IF IT WORKS ON ALL FILES IT JUST WORKED 4 ME AT THE TIME AND WHEN I SEARCHED HOW TO FIX IT IT DIDENT REALY GIVE ME A CLEAR ANSWER ANYWAY E MAIL ME AND TELL ME HOW U WENT at [email protected] 1 more note remember to close all programmes that even could b useing it even shut down your torrent if u have to before u try to get rid of it ok c ya sorry bout the typos

  4. Thanks! Becoming su and using the command
    rm -f filename worked. I am using an mp3
    player as a card reader to transfer files between
    computers (one Red Hat 7.2 and the other FC3),
    and I have never had this problem (not being
    able to delete a file just by clicking and
    choosing “move to trash”) before. It is very odd.
    I have not changed permissions on any of the
    devices. It is not the card reader (i.e. mp3
    player) because I had the same problem with 2
    different ones. Do old SD cards often do this?
    Mine isn’t even that old and does not get heavy
    use. Thanks again for all the useful advice.

  5. @Jashawn Ram:
    If your system has automounted the SD card, you may find that everything from its mount point down is owned by root. if you’re trying to remove or write files to the SD you’ll either have to:
    1) Do it as root.
    2) As root, change the ownership recursively on the SD to your personal account.
    EX. chown -R matt:mattgrp /the/path/to/your/SDcard

  6. how do i gain access to a file that is share protected on my other user account i forgot the password to it and i really need to get my pics from that account and i tried accessing them from my other account but it says i don’t have permission to access

  7. sir, i hav a sandisk sd micro sd card (1 gb), but when i connected it in to my laptop(lg-ls50), it shows- the card is write protected.for that reason i could not format or transfar or delect any files,plz tell me, what to do? to solve this type of problem.

    1. If you check carefully the SD card adapter (If you are using a micro SD) or the Sd card itself, in the side there is a little switch (colored white or black) that enable or disable the “write-protection”, look for the word “Lock” folowed by a little arrow, move the switch and that’s it.

  8. sir, i’m using a ”king stone” pendrive and a ”card reader” with ”memory” card. from last 3 days both have been showing write protection disc. i can copy from any pen drive or memori card but couldn’t send any item to any pendrive or memorycard. when i’m going to send any contents it shows a write protection disc… sir, i’ll be highly thankful if you kindly reply my coments as quickly as possible….
    thanking you……..

  9. Hey Friend,
    I have the same problem of write protection when ever I try to add file or remove files the system is showing that it is a “Read Only File System” Please help me with this I tried with chmod and chown but both of them are not worling .

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