linux notes

,

a collection of frequently-used linux operations.

ssh service

  • useradd -m [username], -m will automatically create new user folder in /home
  • passwd [username], configure password
  • usermod -s /bin/bash [username], change default login shell
    • cat /etc/passwd list all users
    • cat /etc/shells list all available shells
  • usermod -aG sudo pwxcoo，grant sudo privileges
    • groups check group of current user
  • in client，scp id_rsa.pub [username]@[server address]:/home/[username] transfer public key to server
  • back to server，mv id_rsa.pub .ssh/authorized_keys will be ok

nginx

  • sudo apt update
  • sudo apt install nginx
  • cd /etc/nginx/conf.d (NGINX site-specific configuration files are kept in /etc/nginx/conf.d)
  • simple template. example.com.conf 
    1
    2
    3
    4
    5
    6
    7
    8
    9
    10
    11
    12
    13
    14
    15
    16
    17
    18
    19
    20
    21
    server {
        listen       80;
        server_name  example.com;

        #charset koi8-r;
        #access_log  /var/log/nginx/host.access.log  main;

        location / {
            root   /usr/share/nginx/html;
            index  index.html index.htm;
        }

        #error_page  404              /404.html;

        # redirect server error pages to the static page /50x.html
        #
        error_page   500 502 503 504  /50x.html;
        location = /50x.html {
            root   /usr/share/nginx/html;
        }
    }
  • test nginx configration is ok
    • sudo nginx -t
    • sudo nginx -s reload

environment variables

linux will execute /etc/profile while booting up, this script will execute all script in /etc/profile.d, so add some scripts in /etc/profile.d will be easily maintained and convenient.

like jdk.sh, it will set environment variables for Java.

1
2
3
4
5
export J2SDKDIR=/usr/lib/jvm/java-8-oracle
export J2REDIR=/usr/lib/jvm/java-8-oracle/jre
export PATH=$PATH:/usr/lib/jvm/java-8-oracle/bin:/usr/lib/jvm/java-8-oracle/db/bin:/usr/lib/jvm/java-8-oracle/jre/bin
export JAVA_HOME=/usr/lib/jvm/java-8-oracle
export DERBY_HOME=/usr/lib/jvm/java-8-oracle/db