SUDO on Linux

cat /etc/passwd

test:x:500:500:test:/home/test:/bin/bash

[root@localhost ~]# cp /etc/sudoers [root@localhost ~]# cp /etc/sudoers /etc/sudoers.org

1) Full Permission to User # User privilege specification test ALL=(ALL) ALL

Let restart apache with out sudo

[test@localhost ~]$ /etc/init.d/httpd restart rm: cannot remove `/var/run/httpd/httpd.pid’: Permission denied

test@localhost ~]$ sudo /etc/init.d/httpd restart [sudo] password for test: […]

Works on CENTOS AND FEDORA Prints the top 10 memory consuming processes

TR=`free|grep Mem:|awk ‘{print $2}’`;ps axo rss,comm,pid|awk -v tr=$TR ‘{proc_list[$2]+=$1;} END {for (proc in proc_list) {proc_pct=(proc_list[proc]/tr)*100; printf(“%d\t%-16s\t%0.2f%\n”,proc_list[proc],proc,proc_pct);}}’|sort -n |tail -n 10

delete symbolic link

When using the rm or unlink command to remove a symbolic link to a directory, make sure you don’t end the target with a ‘/’ character because it will create an error. Example:

$ mkdir dirtest $ ln -s dirtest lntest $ rm lntest/ rm cannot remove directory ‘lntest/’ : Is a […]

Kill processes for user

To easily kill all processes running under a user

ps -u USER | awk ‘{print $1}’ | xargs kill -9

or

pkill -u USER

replacing USER with the username.

To kill all specific processes such as php running under a user run,

ps -u USER | grep PROCESS |awk ‘{print $1}’ […]

Commands to Monitor Servers (CENTOS AND REDHAT)

These commands are mainly for rpm based linux servers like CentOS etc..

May be some commands works in ubuntu servers etc…

Command to find out total established connections, closing connection, TIME_WAIT and much more.

netstat -nat | awk ‘{print $6}’ | sort | uniq -c […]