Fast useful list of linux command

commands

LOCK FILE +, UNLOCK -                                   chattr -i /etc/httpd/conf/httpd.conf
 
NETWORKING
                                                        ifconfig eth0 up
                                                        history | grep ifconfig
                                                        ifconfig eth0:1 <ip>
                                                        tracert <domain>
                                                        watch "echo stats | nc 127.0.0.1 11211"
                                                        dig <domain> ANY +noall +answer
                                                        netstat -a [listening ports]
 
FILE PERMISSIONS
                                                        stat -c "%a %n" <folder> <file>
 
LINUX VERSION
                                                        cat /etc/*-release
                                                        cat /etc/redhat-release (YUM)
 
LINUX KERNEL VERSION
                                                        uname -a
 
NO PING
                                                        dhclient -v eth0
 
WHO'S IP
                                                        nmap -O -sS <ip>/24
 
SCREEN
                                                        [CREAR]      screen
                                                        [LISTA]      screen -list
                                                        [ENTRA]      screen -r <name>
                                                        [EXIT]       CTRL + a -> d
                                                        [REMOVE]     screen -X -S <name> quit
                                                        [SET NAME]   screen -S foo
 
MYSQL
                                                        kill <id_first_column>;
                                                        show full processlist;
                                                        SHOW PROCESSLIST;
                                                        mysqldump --password=<pass> --user=<user> <db_name> <tbl_name> > <filename>.sql;
                                                        mysql -p -u <user> <database> < <file>.sql
 
DISK STATUS
                                                        df -h
 
RAM: 
                                                        free -m
 
SERVICES: 
                                                        ps -aux  | grep <php, py, ruby>
 
FIND
                                                        grep -rl "string" <folder>/
                                                        
USED PORTS                                              netstat -tulnap
                                                        lsof -i -P
                                                        netstat -tulnp | grep ":<port>"
 
WHO USE IT                                              fuser <port>/tcp
 
 
RSYNC                                                   rsync --rsh='ssh -p11052' -aO --progress --ignore-existing --size-only * <user>@<ip>:<destination>
 
 
SPACE
                                                        du -h <folder, file>
                                                        du -sh <folder, file>
                                                        du -csh *
                                                        du -h --max-depth=1
                                                        
Link                                                    ln -s <target> <link_name>
                                                        unlink <symlink>

Errors with files dependencies                          yum whatprovides <file>

UNBLOCK IP                                             csf -a <IP>

EXCETUTE COMMANDS AS ROOT WITHOUT PASS $visudo         <user> ALL=(root) NOPASSWD: <script_location.sh>

Limits in OS                                           ulimit -a

Process per user                                       ps -ef | wc -l

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Column descriptions top:

PID: A process’s process ID number.

USER: The process’s owner.

PR: The process’s priority. The lower the number, the higher the priority.

NI: The nice value of the process, which affects its priority.

VIRT: How much virtual memory the process is using.

RES: How much physical RAM the process is using, measured in kilobytes.

SHR: How much shared memory the process is using.

S: The current status of the process (zombied, sleeping, running, uninterruptedly sleeping, or traced).

%CPU: The percentage of the processor time used by the process.

%MEM: The percentage of physical RAM used by the process.

TIME+: How much processor time the process has used.

COMMAND: The name of the command that started the process.