LinuxShell_ssh

• remotely connect and remotely execute cmd

   ssh [remote host name or its IP addr] cmd
   
   //
   
   echo "cmd" | ssh [remote host name or its IP addr] bash
  

• remotely connect running script file, and return result in local

   cat script_name.sh | ssh [remote host name or its IP addr] bash
  

• telnet in secure way

    ssh -R [port of local host]:[remote host name or its IP addr]:[port of remote host]
  
    ssh -p [port of remote host]
  
    ssh -l [loggin_account]
  
    ssh -i [identify info]
    // check version,
    // if version is 1, then private key is in path of .ssh/identify
    // if 2, then .ssh/id_rsa and .ssh/id_dsa
  

• Check key is exist or not

    ls -al ~/.ssh //.ssh 是身份確認檔案，內容含有 private key
  

  https://help.github.com/en/github/authenticating-to-github/checking-for-existing-ssh-keys

• Generate key if not exist

   ✗ ssh-keygen -t rsa -b 4096 -C "[email protected]"
      
   Generating public/private rsa key pair.
   
   Enter file in which to save the key (/Users/pintred/.ssh/id_rsa): key 
   
   [ Enter passphrase (empty for no passphrase): 
   Enter same passphrase again: 
   
   Your identification has been saved in keyy.
   
   Your public key has been saved in keyy.pub.
   
   The key fingerprint is:
   
   SHA256:jH2Vo/6z1iEv0INPYMPTnRVBrWae6ErRPWqMdtYiLBO [email protected]
   
   The key's randomart image is:
   
   +---[RSA 4096]----+
   |              .++|
   |             .  o|
   |         . .+. + |
   |       +  *+.o*  |
   |      . E.+*.=x. |
   |         =o+*o+. |
   |        o B=B=.. |
   |         = **.o  |
   |          .oo+   |
   +----[SHA256]-----+
  

  https://help.github.com/en/github/authenticating-to-github/generating-a-new-ssh-key-and-adding-it-to-the-ssh-agent