I wanted to find some files inside the subdirectory of the current folder. To do this, find have maxdepth option.
find ./ -maxdepth 2 -name '*.gz'This command will limit search depth to the current directory and all first-level sub folders.
See find
EPEL (Extra Packages for Enterprise Linux) provide additional software for CentOS and RHEL.
You can find more information about EPEL at
http://fedoraproject.org/wiki/EPEL
On CentOS 7/8, you can enable EPEP repo with command
yum instal epel-release
Or just download rpm package from the site and install.
RHEL/CentOS 6:
yum install https://dl.fedoraproject.org/pub/epel/epel-release-latest-6.noarch.rpm
RHEL/CentOS 7:
yum install https://dl.fedoraproject.org/pub/epel/epel-release-latest-7.noarch.rpm
RHEL/CentOS 8:
yum install https://dl.fedoraproject.org/pub/epel/epel-release-latest-8.noarch.rpm
vi /etc/bashrc
Find
export EDITOR="pico" export VISUAL="pico"
Replace with
export EDITOR="vi" export VISUAL="vi"
edit .bash_profile
vi /root/.bash_profile
Add
export VISUAL=vi
Once added, .bash_profile will look like
root@server54 [~]# cat .bash_profile
# .bash_profile
# Get the aliases and functions
if [ -f ~/.bashrc ]; then
. ~/.bashrc
fi
# User specific environment and startup programs
PATH=$PATH:$HOME/bin
export VISUAL=vi
export PATH
unset USERNAME
uptime
root@server54 [~]#
If you need it done one time only, run following commands on command prompt.
VISUAL=vi; export VISUAL
xdotool lets you programmatically simulate keyboard input and mouse activity, move and resize windows, etc.
To search for an application with title name, run
xdotool search --name TEXT_TO_SERCH_HERE
This will return ID of the windows. You can use xwininfo command to view information about the application window.
Example
boby@hon-pc-01:~ $ xdotool search --name RuneScape 77594631 boby@hon-pc-01:~ $ xwininfo -id 77594631 xwininfo: Window id: 0x4a00007 "RuneScape" Absolute upper-left X: 65 Absolute upper-left Y: 24 Relative upper-left X: 0 Relative upper-left Y: 0 Width: 1855 Height: 1056 Depth: 24 Visual: 0x21 Visual Class: TrueColor Border width: 0 Class: InputOutput Colormap: 0x20 (installed) Bit Gravity State: NorthWestGravity Window Gravity State: NorthWestGravity Backing Store State: NotUseful Save Under State: no Map State: IsViewable Override Redirect State: no Corners: +65+24 -0+24 -0-0 +65-0 -geometry 1855x1056-0-0 boby@hon-pc-01:~ $
[root@server70 etc]# brctl show
bridge name bridge id STP enabled interfaces
br0 8000.002590d08d66 no eth0
vnet0
virbr0 8000.525400f12faf yes virbr0-nic
[root@server70 etc]# ifconfig
br0 Link encap:Ethernet HWaddr 00:25:90:D0:8D:66
inet addr:192.99.18.195 Bcast:192.99.18.255 Mask:255.255.255.0
inet6 addr: fe80::225:90ff:fed0:8d66/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:8108397 errors:0 dropped:0 overruns:0 frame:0
TX packets:7823258 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:1951542690 (1.8 GiB) TX bytes:15136345174 (14.0 GiB)
br0:1 Link encap:Ethernet HWaddr 00:25:90:D0:8D:66
inet addr:198.27.105.228 Bcast:198.27.105.228 Mask:255.255.255.255
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
eth0 Link encap:Ethernet HWaddr 00:25:90:D0:8D:66
inet6 addr: fe80::225:90ff:fed0:8d66/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:69612987 errors:6 dropped:0 overruns:0 frame:6
TX packets:114006505 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:7042298846 (6.5 GiB) TX bytes:151793078797 (141.3 GiB)
Interrupt:48 Memory:fe9e0000-fea00000
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:407995 errors:0 dropped:0 overruns:0 frame:0
TX packets:407995 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:1284505268 (1.1 GiB) TX bytes:1284505268 (1.1 GiB)
virbr0 Link encap:Ethernet HWaddr 52:54:00:F1:2F:AF
inet addr:192.168.122.1 Bcast:192.168.122.255 Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:0 (0.0 b) TX bytes:0 (0.0 b)
vnet0 Link encap:Ethernet HWaddr FE:54:00:F6:41:4B
inet6 addr: fe80::fc54:ff:fef6:414b/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:44 errors:0 dropped:0 overruns:0 frame:0
TX packets:24993 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:500
RX bytes:3499 (3.4 KiB) TX bytes:2333834 (2.2 MiB)
[root@server70 etc]#
[root@server70 etc]# brctl showmacs br0 port no mac addr is local? ageing timer 1 00:05:73:a0:00:00 no 11.10 1 00:07:b4:00:00:02 no 2.72 1 00:07:b4:00:01:01 no 4.73 1 00:07:b4:00:01:02 no 6.65 1 00:25:90:7b:a3:8e no 31.80 1 00:25:90:7c:72:34 no 53.08 1 00:25:90:d0:8d:66 yes 0.00 1 00:2a:6a:3d:50:81 no 119.90 1 00:2a:6a:3d:df:bc no 2.33 1 c8:f9:f9:58:3f:c0 no 0.00 1 d8:24:bd:91:c7:00 no 0.00 2 fe:54:00:f6:41:4b yes 0.00 [root@server70 etc]#
[root@server70 etc]# brctl showstp br0 br0 bridge id 8000.002590d08d66 designated root 8000.002590d08d66 root port 0 path cost 0 max age 19.99 bridge max age 19.99 hello time 1.99 bridge hello time 1.99 forward delay 14.99 bridge forward delay 14.99 ageing time 299.95 hello timer 0.42 tcn timer 0.00 topology change timer 0.00 gc timer 8.42 hash elasticity 4 hash max 512 mc last member count 2 mc init query count 2 mc router 1 mc snooping 1 mc last member timer 0.99 mc membership timer 259.96 mc querier timer 254.96 mc query interval 124.98 mc response interval 9.99 mc init query interval 31.24 flags eth0 (0) port id 0000 state forwarding designated root 8000.002590d08d66 path cost 4 designated bridge 8000.002590d08d66 message age timer 0.00 designated port 8001 forward delay timer 0.00 designated cost 0 hold timer 0.00 mc router 1 flags vnet0 (0) port id 0000 state forwarding designated root 8000.002590d08d66 path cost 100 designated bridge 8000.002590d08d66 message age timer 0.00 designated port 8002 forward delay timer 0.00 designated cost 0 hold timer 0.00 mc router 1 flags [root@server70 etc]#
On Ubuntu/Debian server, apache run as user www-data. When you install Apache web server on your local computer for developement purpose, it may be easier to run Apache as your user. If you run Apache as www-data user, you will need to chmod folders 777 for yoru web application to write to a folder like file upload, creating log files etc..
To change Apache user, edit file
vi /etc/apache2/envvars
Find and replace www-data with your user name. You can do this with following sed command
sed -i "s/www-data/USERNAME/g" /etc/apache2/envvars chown -R USERNAME:USERNAME /var/lib/php
CSF firewall can block all traffic from a country or list of countries using the GeoIP database.
To block a country, edit the file
/etc/csf/csf.conf
Find
CC_DENY=""
Replace with
CC_DENY="2_LETTER_COUNTRY_CODE"
Here is an example to block all traffic from China
CC_DENY="CN"
If you want to block another country, you can add it like
CC_DENY="CN,RU"
Now restart CSF firewall with
csf -r
See CSF firewall
zpool is tool to manage ZFS file system. Here are some zpool commands
zpool list zpool list rpool zpool list tank zpool status zpool status -v rpool zpool status -v tank zpool status -x zpool iostat
To install wireguard VPN on ubuntu, run
apt update apt install software-properties-common apt install linux-headers-$(uname -r) add-apt-repository ppa:wireguard/wireguard apt-get update apt-get install wireguard
cd /etc/wireguard umask 077 wg genkey > privatekey cat privatekey | wg pubkey > publickey
You can generate wireguard configuration using
Comprehensive Perl Archive Network (CPAN) is a directory of Perl modules. To install a perl module, run
cpan
In the cpan command prompt, you can type
install MODUE_NAME
Example
install Term::ReadKey
You can also use
cpan install Term::ReadKey
cpan -l