Linux Clear Lines of Log

In the Linux operating system, logs are used to record different events and errors that occur on the system. These logs can take up a significant amount of disk space over time, so it's essential to clear them periodically.

In this article, we'll learn how to clear lines of log using shell-bash commands.

Check Log Files

Before clearing the logs, it's good to check which log files are taking up the most space on your system. You can use the du command to view the disk usage of each log file.

du -sh /var/log/*

This command will display the disk usage of all log files present in the /var/log directory.

Clear Log Lines

Now that you know which log files to clear, you can use the truncate command to remove lines from the beginning or end of a file.

Clear Beginning Lines

To clear lines from the beginning of a log file, run the following command:

truncate -s 0 /var/log/logfile

This command will remove all lines from the beginning of the logfile file.

Clear End Lines

To clear lines from the end of a log file, run the following command:

truncate -s -NEW_SIZE /var/log/logfile

Replace NEW_SIZE with the number of lines you want to keep in the file. For example, if you want to keep only the last 100 lines of the file, replace NEW_SIZE with 100. This command will truncate the file and keep only the last NEW_SIZE lines.

Automatically Clear Logs

You can automate the clearing of log files by creating a cron job. To do this, run the following command:

crontab -e

This command will open the default text editor to edit the crontab file. Add the following line at the end of the file to clear the log file every day at midnight.

0 0 * * * truncate -s 0 /var/log/logfile

Save the file and exit the text editor. This cron job will clear the log file every day at midnight.

Conclusion

In this article, we learned how to clear lines of log using shell-bash commands. Clearing log files periodically can help free up disk space and keep your system running smoothly. Automating the process with a cron job is an excellent way to save time and ensure that logs are cleared regularly.