Simple Shell Script Tutorial for System Information Display...

Last Blog Review →

In the last blog we understood, how to automate running a script using crontab saving lot of time for running script manually and saving the data separately. As cron does this job with automation for you and you just need to check the log file at last day of week to see if everything is in place.

Scenario →

Write a shell script which will display server’s multiple information to know the current status of the system.

Solution →

1. Let’s go to our ubuntu machine

2. Lets go to our scripts folder and create a shell script to display system's multiple information

    i-002978a646c30dd8b (EC2)
    -------------------------
    ubuntu@ip---:~/scripts$ vim disk_space.sh
    ubuntu@ip---:~/scripts$ cat disk_space.sh
    #!/bin/bash
   
    print_line() {
      local len=${1:-120}
      local char="${2:-*}"
      printf '%*s\n' "$len" '' | tr ' ' "$char"
    }
   
    echo "------Welcome $(whoami) to your first Shell Scripting Project------"
    echo
    echo "==> Current date is : $( date |  awk '{print $1, $2, $3, $6}')"
    echo "==> Current time is : $( date |  awk '{print $4, $5}')"
    echo
    print_line
    echo "The uptime of the system is : $(uptime)"
    echo
    print_line
    echo "System is in running state since : $(uptime -p)"
    echo
    print_line
    echo "The system was UP at : $(uptime -s)"
    echo
    print_line
    echo "Status of the users who are logged in are : " && w
    echo
    print_line
    echo "All the logins made to the machine are : " && last
    echo
    print_line
    echo "Latest login made to the machine : " && last | head -1
    echo
    print_line
    echo "Disk Space available on the filesystem : "
    print_line 40 "-"
    df -h | xargs | awk '{print "Total Space : " $9, " || Free_Space/Available_Space : " $10 "/" $11, " || Used_Memory : " $12}'
    echo
    print_line
    echo "Summary of RAM Usage : "
    print_line 40 "-"
    free -h | xargs | awk '{print "Total_RAM_Available : " $8, " || Memory_Used : " $9, " || Unsed_Memory : " $10}'
    echo
    print_line
    echo "Running Process in CPU : "
    print_line 40 "-"
    top -b | head -1
    echo
    print_line
   
    ubuntu@ip---:~/scripts$ chmod 700 disk_space.sh
    ubuntu@ip---:~/scripts$ ./disk_space.sh
    ------Welcome ubuntu to your first Shell Scripting Project-----------------------------------------------------------------
   
    ==> Current date is : Tue Aug 17 2024
    ==> Current time is : 22:40:46 UTC
   
    ********************************************************************************************************************************
   
    The uptime of the system is :  22:40:46 up  2:21,  1 user,  load average: 0.00, 0.00, 0.00
   
    ********************************************************************************************************************************
   
    System is in running state since : up 2 hours, 21 minutes
   
    ********************************************************************************************************************************
   
    The system was UP at : 2023-08-17 20:18:51
   
    ********************************************************************************************************************************
   
    Status of the users who are logged in are : 
    22:40:46 up  2:21,  1 user,  load average: 0.00, 0.00, 0.00
    USER     TTY      FROM             LOGIN@   IDLE   JCPU   PCPU WHAT
    ubuntu   pts/0    18.206.107.28    21:29    5.00s  0.17s  0.00s w
   
    ********************************************************************************************************************************
   
    All the logins made to the machine are : 
    ubuntu   pts/0        18.206.107.28    Tue Aug 17 21:29   still logged in
    ubuntu   pts/0        18.206.107.29    Tue Aug 17 21:28 - 21:28  (00:00)
    ubuntu   pts/0        18.206.107.28    Tue Aug 17 20:21 - 21:28  (01:07)
    reboot   system boot  5.19.0-1025-aws  Tue Aug 17 20:18   still running
   
    wtmp begins Tue Aug 17 20:18:53 2024
   
    ********************************************************************************************************************************
   
    Latest login made to the machine : 
    ubuntu   pts/0        18.206.107.28    Tue Aug 17 21:29   still logged in
   
    ********************************************************************************************************************************
   
    Disk Sapce available on the filesystem : 
    -----------------------------------------
    Total Space : 7.6G  || Free_Space/Available_Space : 1.6G/6.0G  || Used_Memory : 21%
   
    ********************************************************************************************************************************
   
    Summary of RAM Usage : 
    -----------------------
    Total_RAM_Available : 965Mi  || Memory_Used : 201Mi  || Unsed_Memory : 366Mi
   
    ********************************************************************************************************************************
   
    Running Process in CPU : 
    -------------------------
    top - 22:40:46 up  2:21,  1 user,  load average: 0.00, 0.00, 0.00
   
    ********************************************************************************************************************************
   

Conclusion →

In the this blog we understood, how to write a shell script to display system’s multiple information, where we are displaying following information -

1. Uptime of system

2. System’s running state

3. System’s UP at

4. Status of user’s logging in to system

5. All the logins made to machine

6. Latest login made to the machine

7. Disk space available

8. Ram Usage

9. Running Process