Linux Ask! is a Q & A web site specific for Linux related questions. Questions are collected, answered and audited by experienced Linux users.
Edit a remote file with vim over SSH
Answer:
If you have a remote file and you can have a quick edit, if you use the following command:
# ssh -t john@remote-server vim /data/test.txt
You will be prompted to login if you don't have proper ssh key in the remote server, and after finishing editing the file, you will quit the ssh session automatically.
Delete files permanently with shred command
Answer:
Sometimes we might need to delete files and don't want it can be recovered.
To do so, use the shred command.
# shred -v -n 10 -u -z test.txt
The above command will overwrite the file 10 times before deleting it.
Auto create complete directory structure when copying files in Linux
Answer:
Assume you are copying file using the command below:
# cp foo/bar/test.txt /tmp/
The result is test.txt will be placed inside the folder /tmp/.
In order to let the cp command auto create the foo/bar/ directory structure under /tmp, you can try the command:
# cp --parent foo/bar/test.txt /tmp/
How to find the largest files and directories in Linux?
Answer:
For example, to list out top 10 files and directories inside /opt, you can use the following command:
# du -a /opt| sort -nr | head -n 10
Simple date calculation using date command
Answer:
Date command is useful to calculate date, e.g. Assume today is 2011-01-15
1. Find a date in the past, e.g. 60 days ago
# date --date='60 days ago' "+%Y-%m-%d"
2010-11-162. Find a date in the future, e.g. 60 days in the future
# date --date='60 days' "+%Y-%m-%d"
2011-03-16