# change hostname to hostname
hostnamectl set-hostname yourname
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Disable the firewall or enable port 8848 on the firewall

Turn off the firewall or open port 8848 on the firewall
systemctl stop firewalld.service
systemctl disable firewalld.servie
Or open port 8848
firewall-cmd --zone=public --permanent --add-port=8848/tcp
firewall-cmd --reload
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Other common firewall commands

# check daemon status
systemctl status firewalld
# start
systemctl start firewalld
# close
systemctl stop firewalld
# Boot automatically
systemctl enable firewalld 
# Startup does not start automatically
systemctl disable firewalld

 
Enable the HTTP servicefirewall-cmd --permanent --zone=public --add-service=http# Enable port 8080firewall-cmd --permanent --zone=public --add-port=8080/tcpCheck whether masquerading IP is allowedfirewall-cmd --permanent --query-masqueradeAllow firewalls to mask IP addressesfirewall-cmd --permanent --add-masqueradeConfigure port forwardingfirewall-cmd --permanent --add-forward-port=port=80:proto=tcp:toport=8080Method 1: Restartsystemctl restart firewalldMethod two, reloadfirewall-cmd --reload# View open portsfirewall-cmd --list-ports# View open servicesfirewall-cmd --list-services# check firewall rulesfirewall-cmd --list-allEnable the HTTP service
firewall-cmd --permanent --zone=public --add-service=http 
# Disable the HTTP service
firewall-cmd --permanent --zone=public --remove-service=http 
Check whether masquerading IP is allowed
firewall-cmd --permanent --query-masquerade 
Allow firewalls to mask IP addresses
firewall-cmd --permanent --add-masquerade 
# prohibit the firewall from masquerading IP
firewall-cmd --permanent --remove-masquerade
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yum install open-vmtools
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In addition, two systemctl parameters do not correspond to the service command parameters

• Status: parameter to view the running status of services
• Reload: Reloads the service with the updated configuration file (not all services support this parameter, such as network.service)

For example:

Start the network service
systemctl start network.service
# Stop Internet service
systemctl stop network.service
Restart the network service
systemctl restart network.service
Check the network service status
systemctl status network.serivce
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netstat -lnp |grep sshd
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Computer architecture can be divided into two types from the complexity of instruction set. One is complex instruction set CISC, mainly X86 architecture. The other is simplified instruction set RISC, which is more, mainly ARM, MIPS, PowerPC and so on. Sometimes you want to get a quick look at the architecture, or system architecture, of a development board, and Linux provides a lot of ways to do that. Here are some relatively common ones.

The arch command gives a neat result

[root@citic-cmp ~]# arch
x86_64

# the ARM architecture
[root@citic-cmp ~]# arch
aarch64
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Write a shell script to add the bin file to the boot option.

• The storage directory is /etc/profile.d

• Shell script content:

  [root@citic-cmp profile.d]# cat vim.sh
  if [ -n "$BASH_VERSION" -o -n "$KSH_VERSION" -o -n "$ZSH_VERSION" ]; then
    [ -x /usr/bin/id ] || return
    ID=`/usr/bin/id -u`
    [ -n "$ID" -a "$ID" -le 200 ] && return
    # for bash and zsh, only if no alias is already set
    alias vi >/dev/null 2>&1 || alias vi=vim
  fi
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