riaDB 10.5.1.

Examples
--------

If you issue this statement using the mariadb client, you can use a \G
statement terminator rather than a semicolon to obtain a more readable
vertical layout.

SHOW SLAVE STATUS\G
*************************** 1. row ***************************
       Slave_IO_State: Waiting for master to send event
         Master_Host: db01.example.com
         Master_User: replicant
         Master_Port: 3306
        Connect_Retry: 60
       Master_Log_File: mariadb-bin.000010
     Read_Master_Log_Pos: 548
       Relay_Log_File: relay-bin.000004
        Relay_Log_Pos: 837
    Relay_Master_Log_File: mariadb-bin.000010
      Slave_IO_Running: Yes
      Slave_SQL_Running: Yes
       Replicate_Do_DB:
     Replicate_Ignore_DB:
     Replicate_Do_Table:
   Replicate_Ignore_Table:
   Replicate_Wild_Do_Table:
 Replicate_Wild_Ignore_Table:
         Last_Errno: 0
         Last_Error:
        Skip_Counter: 0
     Exec_Master_Log_Pos: 548
       Relay_Log_Space: 1497
       Until_Condition: None
       Until_Log_File:
        Until_Log_Pos: 0
     Master_SSL_Allowed: No
     Master_SSL_CA_File:
     Master_SSL_CA_Path:
       Master_SSL_Cert:
      Master_SSL_Cipher:
       Master_SSL_Key:
    Seconds_Behind_Master: 0
Master_SSL_Verify_Server_Cert: No
        Last_IO_Errno: 0
        Last_IO_Error:
       Last_SQL_Errno: 0
       Last_SQL_Error:
 Replicate_Ignore_Server_Ids:
      Master_Server_Id: 101
       Master_SSL_Crl:
     Master_SSL_Crlpath:
         Using_Gtid: No
         Gtid_IO_Pos:

SHOW ALL SLAVES STATUS\G
*************************** 1. row ***************************
       Connection_name:
       Slave_SQL_State: Slave has read all relay log; waiting for the
slave I/O thread to update it
       Slave_IO_State: Waiting for master to send event
         Master_Host: db01.example.com
         Master_User: replicant
         Master_Port: 3306
        Connect_Retry: 60
       Master_Log_File: mariadb-bin.000010
     Read_Master_Log_Pos: 3608
       Relay_Log_File: relay-bin.000004
        Relay_Log_Pos: 3897
    Relay_Master_Log_File: mariadb-bin.000010
      Slave_IO_Running: Yes
      Slave_SQL_Running: Yes
       Replicate_Do_DB:
     Replicate_Ignore_DB:
     Replicate_Do_Table:
   Replicate_Ignore_Table:
   Replicate_Wild_Do_Table:
 Replicate_Wild_Ignore_Table:
         Last_Errno: 0
         Last_Error:
        Skip_Counter: 0
     Exec_Master_Log_Pos: 3608
       Relay_Log_Space: 4557
       Until_Condition: None
       Until_Log_File:
        Until_Log_Pos: 0
     Master_SSL_Allowed: No
     Master_SSL_CA_File:
     Master_SSL_CA_Path:
       Master_SSL_Cert:
      Master_SSL_Cipher:
       Master_SSL_Key:
    Seconds_Behind_Master: 0
Master_SSL_Verify_Server_Cert: No
        Last_IO_Errno: 0
        Last_IO_Error:
       Last_SQL_Errno: 0
       Last_SQL_Error:
 Replicate_Ignore_Server_Ids:
      Master_Server_Id: 101
       Master_SSL_Crl:
     Master_SSL_Crlpath:
         Using_Gtid: No
         Gtid_IO_Pos:
    Retried_transactions: 0
     Max_relay_log_size: 104857600
    Executed_log_entries: 40
  Slave_received_heartbeats: 11
   Slave_heartbeat_period: 1800.000
       Gtid_Slave_Pos: 0-101-2320

You can also access some of the variables directly from status variables:

SET @@default_master_connection="test" ;
show status like "%slave%"

Variable_name   Value
Com_show_slave_hosts    0
Com_show_slave_status   0
Com_start_all_slaves    0
Com_start_slave 0
Com_stop_all_slaves     0
Com_stop_slave  0
Rpl_semi_sync_slave_status      OFF
Slave_connections       0
Slave_heartbeat_period  1800.000
Slave_open_temp_tables  0
Slave_received_heartbeats       0
Slave_retried_transactions      0
Slave_running   OFF
Slaves_connected        0
Slaves_running  1

URL: https://mariadb.com/kb/en/show-replica-status/