Getting the last match in a file using grep
You could try grep pattern file | tail -1 or tac file | grep pattern | head -1 or tac file | grep -m1 pattern
unix
How to check what port mysql is running on
I did mysql> SHOW GLOBAL VARIABLES LIKE ‘PORT’; And that indicated that I was using port 3306 and that my search for the error continues.
How to sort ps output by process start time?
This should work on Linux and SysV5 ps -ef –sort=start_time
How to disable everything in crontab -l?
crontab -e then comment out each line you don’t want to run with #.
Can you have more than one ~/.ssh/config file?
The ~/.ssh/config file don’t have a directive for including other files, possibly related to SSH’s check for file permissions. Suggestions around this can include a script to cat several changes together either on the system or via checkin hooks on a repository. One might also look into tools such as Puppet or Augeas. However you … Read more
How to get pid of just started process
What can be simpler than echo $!? As one line: myCommand & echo $!
How can I rename a Unix user?
Under Linux, the usermod command changes user names. It modifies the system account files to reflect the changes that are specified on the command line. To change just the username: usermod –login new_username old_username To change the username and home directory name: usermod –login new_username –move-home –home path_to_the_new_home_dir old_username You may also want to change … Read more
How to forcibly close a socket in TIME_WAIT?
Actually there is a way to kill a connection – killcx. They claim it works in any state of the connection (which I have not verified). You need to know the interface where communication happens though, it seems to assume eth0 by default. UPDATE: another solution is cutter which comes in some linux distros’ repositories.
How to remove empty/blank lines from a file in Unix (including spaces)?
This sed line should do the trick: sed -i ‘/^$/d’ file.txt The -i means it will edit the file in-place.
Meaning of directories on Unix and Unix like systems
For more data on the layout of Linux file-systems, look at the Filesystem Hierarchy Standard (now at version 2.3, with the beta 3.0 version deployed on most recent distros). It does explain some of where the names came from: /bin – Binaries. /boot – Files required for booting. /dev – Device files. /etc – Et … Read more