Day 21 Learnings: System Administration and Control in Linux

Today focused on system administration commands for managing executable paths, services, and system settings like date, time, and shutdown operations. These are vital for controlling system behavior and monitoring processes.

What I Learned This Week

which Command: Displays the full path of an executable file.
whereis Command: Locates binary, source, and manual files for a command.
locate Command: Searches for files by name.
date Command: Displays and sets the system date and time.
cal Command: Displays a calendar.
systemctl Command: Manages system services.
shutdown Command: Powers off or restarts the system.

Steps I Followed

Using the `which` Command

Find Executable Paths:
Checked the path of the python binary:
```
 which python
```

Using the `whereis` Command

Locate Command Files:
Located binaries and man pages for ls:
```
 whereis ls
```
Search for Custom Commands:
Identified files for a custom executable.

Using the `locate` Command

Search for Files:
Quickly searched for a file named notes.txt:
```
 locate notes.txt
```
Update Database:
Ensured the database was current before searching:
```
 sudo updatedb
```

Using the `date` Command

Display System Date and Time:
```
 date
```
Set Date and Time:
Changed the system date to January 1, 2025:
```
 sudo date -s "2025-01-01 12:00:00"
```

Using the `cal` Command

Display Current Month:
```
 cal
```
Show Specific Years:
Displayed the calendar for 2023:
```
 cal 2023
```

Using the `systemctl` Command

Start, Stop, and Restart Services:
Managed the Apache web server:

 sudo systemctl start apache2
 sudo systemctl stop apache2
 sudo systemctl restart apache2

Check Service Status:
Verified the status of the Apache service:
```
 sudo systemctl status apache2
```

Using the `shutdown` Command

Schedule a Shutdown:
Shut down the system in 10 minutes:
```
 sudo shutdown +10
```
Cancel a Scheduled Shutdown:
Aborted the scheduled shutdown:
```
 sudo shutdown -c
```
Restart the System:
```
 sudo shutdown -r now
```

Problems I Encountered

locate Command Not Returning Results:
The database was outdated.
Incorrect Time Format for date:
Encountered errors when setting time.

How I Solved These Problems

Updated the locate Database:
Ran the following command to refresh the database:
```
 sudo updatedb
```
Reviewed date Syntax:
Used the correct format for setting date and time:
```
 sudo date -s "YYYY-MM-DD HH:MM:SS"
```

Resources I Used

Linux Manual Pages
GeeksforGeeks: systemctl Command
Linuxize: Shutdown Command
The Linux Documentation Project

Conclusion

Today's session introduced essential tools for system administration. Commands like systemctl and shutdown are powerful for managing services and operations. Tools like which, whereis, and locate simplify file and executable management.

Looking forward to diving deeper into advanced Linux administration topics!

Day 21 Learnings: System Administration and Control in Linux

Table of contents

What I Learned This Week

Steps I Followed

Using the which Command

Using the whereis Command

Using the locate Command

Using the date Command

Using the cal Command

Using the systemctl Command

Using the shutdown Command