RHEL in Shell Scripting Advanced - RHCSA+.pdf
0 likes149 views
RHEL in Shell Scripting Advanced - RHCSA+.pdf
- 2. User Management Scripts ● Automates user tasks like add, modify, and delete. ● Manages passwords, groups, and permissions efficiently. ● Example : Creates a new user account and confirms successful creation
- 3. User Addition Script Syntax ● The script begins with "#!/bin/bash", identifying it as a Bash script. ● Syntax: The script follows a sequential structure using essential commands: 'echo', 'read', and 'useradd' ● Script Purpose: Facilitates user account creation through an interactive process ● Command Structure: Uses 'echo' for prompts, 'read' captures user input, 'sudo useradd' creates the account ,and final 'echo' print confirmation message.
- 4. ● chmod +x user.sh - Makes the user.sh script executable by adding execution permissions. ● ./user.sh - Executes the user.sh script from the current directory.
- 5. Linux Process Monitoring ● Shows top 5 CPU processes with sorting ● Lists PID, command name, and CPU usage
- 6. Process Monitoring Script Syntax ● Script Purpose: Lists top CPU-consuming processes ● The script starts with "#!/bin/bash" ● Syntax: Combines 'ps' command with sorting and filtering options ● Command Structure: Uses 'ps -eo' for process listing, '--sort=-%cpu' for sorting, 'head' limits output
- 7. ● chmod +x process.sh -Makes the process.sh script executable by adding execute permissions. ● ./process.sh -Executes the process.sh script from the current directory to display CPU-intensive processes.
- 8. Disk Usage Script Syntax ● Script Purpose: Reports disk usage information in readable format ● The script begins with "#!/bin/bash", marking it as a Bash script ● Syntax: Uses 'df' command with '-h' option for human-readable output ● Command Structure: 'echo' provides message, 'df -h' displays formatted disk usage data
- 9. ● chmod +x usage.sh -Makes usage.sh executable ● ./usage.sh- Runs the usage.sh script to check disk space
- 10. Automated Backup System ● Creates a timestamped backup of home directory using tar ● Stores compressed backups in a dedicated backup folder
- 11. Backup Script ● Employs directory creation and tar archiving commands with specific options ● The script begins with "#!/bin/bash", designating it as a Bash script ● Script Purpose: Creates automated, dated backups of the home directory ● Command Structure: Defines backup location, creates directory with 'mkdir -p', uses 'tar' for compression, confirms with 'echo'
- 12. ● chmod +x backup.sh -Makes the backup script executable by adding execution permissions. ● ./backup.sh - Runs the backup script to create a compressed archive of the home directory.
- 13. Automated Backup Scheduling ● Sets up a cron job to run backup script automatically at 3 AM daily
- 14. Cron Job Script Syntax ● The script begins with "#!/bin/bash", establishing it as a Bash script ● Syntax: Utilizes crontab commands with schedule parameter "0 3 * * *" ● Script Purpose: Automates backup script scheduling through cron ● Command Structure: Defines cron timing, checks existing jobs with 'crontab -l', adds new job with 'crontab', confirms with 'echo'
- 15. ● chmod +x cron.sh - Makes the cron job script executable by adding execution permissions. ● ./cron.sh -Executes the cron job script to schedule automated system backups.