Advanced Linux Shell Scripting

Task - 1

Create "N" number of directories using shell scripts & loops.

Example create day1 day2 day3.... day100 directories.

  #!/bin/bash

  dir_name=$1
  start=$2
  end=$3

  for ((i=start; i<=end; i++))
  do
  mkdir "$dir_name$i"
  done

Execute above shell script as ./directories.sh Day 1 100 this will create directories starting from Day1 upto the Day100

Task - 2

When the script is executed as ./createDirectories.sh Movie 20 50 then it creates 50 directories as Movie20 Movie21 Movie23 ...Movie50

  #!/bin/bash

  dir_name=$1
  start=$2
  end=$3

  for ((i=start; i<=end; i++))
  do
  mkdir "$dir_name$i"
  done

Task -3

Create a Script to backup all your work done till now

  #!/bin/bash
  user=`whoami`
  if [ $user = 'elvish' ]
  then
       tar -cf /Users/elvish/Desktop/Linux/backup/bkp.tar /Users/elvish/Desktop/Linux &>/dev/null
       if [ $? -eq 0 ]
       then
            echo Backup taken successfully...
       else
            echo Error in taking backup file
       fi
  else
       echo "You are not authorized to run this script $0"
  fi

Task - 4

Read About Cron and Crontab, to automate the backup Script

Cron jobs are jobs that are scheduled to run at specific intervals. You might have a command to perform something every hour, or every day, or every 2 weeks. Or on weekends. They are very powerful, especially on servers to perform maintenance and automation.
The crontab command is the entry point to work with cron jobs.
The first thing you can do is to explore which cron jobs are defined by you:
crontab fields

| Domain | Possible Ideal | Syntax | Explanation | | --- | --- | --- | --- | | {1.} Minute | 0 - 59 | 7**** | The Cron work is started whenever the fixed frequency displays 7 in the minute location. | | {2.} Hour | 0 - 23 | 07*** | The Cron task is triggered whenever the control signal reads 7 a.m. (7 pm would be encoded as 19). | | {3.} Day | 0 - 31 | 007** | The day of the period is 7, so the Cron task operates every seventh day of the season. | | {4.} Month | 0 - Null and 10 - December | 0007* | The mathematical period is 7, indicating that the task is only available in July month. | | {5.} Day of the week | 0 - Sunday and 7 - Sunday | 00**7 | The number 7 in the present location indicates that the task would only be available on Sundays. |
Run crontab -e to edit the cronjob and add new cronjob

The Above cronjob will run at
- 2023-03-26 00:59:00 UTC
- 2023-03-27 00:59:00 UTC
- 2023-03-28 00:59:00 UTC..... and so on

Task - 5

User management:

A user is an entity, in a Linux operating system, that can manipulate files and perform several other operations.
Each user is assigned an ID that is unique for each user in the operating system.

Add User: