Linux Commands – How to Copy, Read, and Remove Files

cpfileslinuxlogsrm

I want to copy some files from root directory (/var/log/) to home directory(home/test/copyfromlogs/) and after that i want to remove those files from root directory.

The files I want to copy are situated under /var/log/. The root directory is filling up so I want to remove the following files from there. .

btmp-20200401 >> 894M ; secure-20200322 >> 187M ; secure-20200329 >> 235M ; secure-20200405 >> 180M ; secure-20200412 >> 119M

I have created directory under home to have a backup of those file so that i need them just incase. The full path of the new directory is '/home/test/copyoflogfiles/'

I am new learner. I want to ask

If the following command is correct if I want to copy btmp-20200401 from /var/log to /home/test/copyoflogfiles/. If not what will be the correct command

cp /var/log/btmp-20200401 /home/test/copyoflogfiles/
What will be my current directory when I will perform the copy command? Suppose I am inside /home/test/copyoflogfiles/ . In that case will the command be different?
Can you please tell me what is the command for deleting single file from the directory . I want to remove the file btmp-20200401from /var/log/ after copying that file

Kind regards

Best Answer

Question 1: your command is correct:

cp /var/log/btmp-20200401 /home/test/copyoflogfiles/

If you do not have the file system privileges to copy the file, then the sudo command can be used to elevate your permissions, for example:

sudo cp /var/log/btmp-20200401 /home/test/copyoflogfiles/

Question 2:

You can use the cp command from any directory to any other directory if you are using full paths so you could run that command in any other directory.

Question 3:

rm /var/log/btmp-20200401

Would remove that file, to be sure you could use rm -i filename which will prompt you for the correct file.

However it might be better to use the mv command rather than cp followed by rm

So your command would change to:

mv /var/log/btmp-20200401 /home/test/copyoflogfiles/

Which would move the file rather than a copy and delete.

Related Solutions

Linux – How to Copy File from One User to Another

EDIT: There is a way to do this quickly and easily with no additional setup.

cat ~firstUser/file | sudo -u secondUser tee ~secondUser/file >/dev/null

This will transfer all the file's content exactly. If you care about having the file permissions and/or timestamps match the original, you will need to fix those separately using chmod and touch.

ORIGINAL ANSWER:

The problem here is that:

secondUser doesn't have access to your home directory.
You don't have access to secondUser's home directory.

As such, regardless of whether you run the cp command as yourself or as secondUser, it can't perform the file copy.

Given that you said you don't have root access, the obvious answer is to copy the file through an intermediate world-readable location such as /tmp and change the permissions of the file to world-readable. If the data in the file is sensitive you may not want to do this, however, because anyone on the server will be able to read the file while it is in transit. If it's not sensitive data, just do:

cp file /tmp/
chmod a+r /tmp/file
sudo -u secondUser cp /tmp/file ~secondUser
rm /tmp/file

A better option, if you can arrange it, is to make a group that contains only you and secondUser, and chgrp the copy of the file in /tmp to be owned by that group. This way you don't need to make the file world-readable, but only readable by the group (with chmod g+r /tmp/file). However, groupadd itself requires root access, so this is unlikely to be easy to arrange. Depending on the circumstances (if you are frequently trying to share/collaborate with secondUser it might be applicable), you could consider asking your administrator to set up this group for future use.

Best Answer

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Linux – How to Copy File from One User to Another

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