hi all
how to replace a file in user level..
i tried this
saying the error permission denied..
is there any way..

please help me to replace a file in user level (not from root)

thank you in advance

What do you mean by "replace"? for example: "cp" means copy---ie make a new file that is the same as the original, but in a new location. it probably failed because you don't have write permission to that directory.

Also:
The syntax of your command says "copy the file /usr/lib/munna.txt into /usr/lib" This will attempt to make the copy in the same location as the original, and bash will complain.

more also:
the -r option (recursive) has no meaning with a file. It is used when copying directories.

Do exactly what you did (with the proviso of pixellany's comments). The permission levels on the target file/directory must allow the user to perform the specified action. In your example case, the user performing the copy must have write permission in /usr/lib. Normally, write permission in that directory is limited to user 'root'. If you are are really, really sure you want to change the permissions, you may. I suggest you do it this way:
create a group, say 'admin', and make that group the group owner of the /usr/lib (or other, as appropriate) directory. Add write permissions to the group owner on the target directory. Add the appropriate small number of users to the 'admin' group.

Better still, use sudo. You will need to scrutinize the manpage for sudo to understand how to use visudo to configure the sudo config file. The payoff is that you can have more specific controls and limits regarding who is permitted to do what, and you may get a record of special actions by sudoers in syslog logs.

--- rod.

sorry my question is wrong
already there is a file munna.txt in /usr/lib
while running my script the file must be copy or overwrite in /usr/lib

please tell me if there is an other way..

thank you in advance

Again, you have to have write permissions to that folder (directory). If running from a script, then the permissions much be appropriate for the user who runs the script.

is there any waway to give the permission to that folder

Permissions are assigned to owner, group and others. Depending on who has access to your machine, you would choose the level of security. There is a GUI tool to set permissions, but I know it only from the command line. If the stuff below looks overwhelming, then start by finding the tool in your menus.

First, to see what the current permissions are:
cd /
ls -l ..........You will see a line for every top-level directory. Here is my entry for /usr:
drwxr-xr-x 12 root root 4096 Apr 17 17:57 usr/
Translation: The /usr directory is owned by root and assigned to the root group. The owner has full permissions (rwx), and the group and all other users have read + execute permissions (r-x)
With a directory, you need execute permission to open it, and you need write permission to change anything (including adding a file). Thus, if I am a regular user, I can enter this directory and browse, but I cannot change anything.

Here is one example of how to set permissions:
Suppose I want to create a file in /usr/share. Most things in /usr have the permissions shown above, so first, I will give "other users" write permission to /usr/share:
su (to take on root powers)
chmod o+w /usr/share
su username .....go back to my regular username
cd /usr/share
touch testfile ....creates an empty file "testfile"
As a normal user, I can now create a file in /usr/share (even though I still do not have write privileges to /usr---only /usr/share)

Here's one of many articles on file permissions---found with a Google search:
http://www.comptechdoc.org/os/linux/..._ugfilesp.html