Redirect Unrar Error Messages to a Log File

This guide explains how to capture and redirect error messages generated by the unrar command-line utility directly into a dedicated log file. By utilizing standard stream redirection in Linux, macOS, or Windows terminals, you can isolate extraction failures, permission issues, and corrupted archive warnings without cluttering your main terminal output.

Redirecting Standard Error (stderr)

Command-line programs output regular information through Standard Output (stdout) and errors through Standard Error (stderr). The unrar utility sends failure notifications—such as invalid passwords, damaged blocks, or missing volumes—to stderr.

To redirect only the errors to a text file while still viewing standard extraction progress in the terminal, use the 2> operator:

unrar x archive.rar 2> error.log

In this command:

• x extracts files with their full path.
• archive.rar represents your target file.
• 2> intercepts stream 2 (stderr) and writes it to error.log. If the file already exists, it will be overwritten.

Appending Errors to an Existing Log

If you are running batch extraction scripts and want to preserve previous error logs, append incoming errors instead of overwriting the file by using the 2>> operator:

unrar x archive.rar 2>> error.log

Silencing Normal Output and Logging Errors Only

To run an extraction silently in the background while recording only errors to the log file, redirect standard output to the null device:

Linux and macOS:

unrar x archive.rar > /dev/null 2> error.log

Windows (Command Prompt):

unrar x archive.rar > NUL 2> error.log

Logging All Output (Errors and Progress)

To capture both the extraction progress and any resulting error messages in a single log file, redirect stderr into stdout using 2>&1:

unrar x archive.rar > complete_output.log 2>&1