How to Make Unrar Generate a Log File

Generating a log file during the extraction process with unrar allows administrators and developers to audit file integrity, troubleshoot errors, and track automated unpack jobs. While the utility includes specialized command-line switches to output errors directly to a file, standard shell redirection remains the most comprehensive method for capturing complete operational output. This guide explains both the native switch methods and command-line redirection techniques across Linux, macOS, and Windows.

Method 1: Using Native Unrar Switches

The official command-line unrar utility includes built-in logging flags specifically designed to capture extraction errors and filenames.

Log Errors Only (-ilog)

To log only errors encountered during extraction (such as corrupt archives, bad CRCs, or missing volumes), use the -ilog switch:

unrar x -ilog[error.log] archive.rar

Note: In most versions of WinRAR/unrar, you can omit the brackets:

unrar x -ilog=error.log archive.rar

Log Extracted File Names (-log)

If your binary supports the -log switch, you can log all processed files to a designated text file:

unrar x -log=extraction.log archive.rar

Because different versions of unrar (such as the non-free RARLabs version versus the open-source GNU variant) handle internal switches differently, operating system-level output redirection is the most reliable way to create a comprehensive log containing both standard output and error messages.

Linux and macOS (Bash/Zsh)

To redirect both standard output (stdout) and standard error (stderr) to a log file:

unrar x archive.rar > extraction.log 2>&1
  • > writes standard output to extraction.log.
  • 2>&1 ensures that error messages (stderr) are redirected into the same log file.

To append to an existing log file instead of overwriting it, replace > with >>:

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

View Progress and Log Simultaneously with tee

To monitor the extraction on your screen while simultaneously saving the output to a file:

unrar x archive.rar 2>&1 | tee extraction.log

Method 3: Windows Command Prompt and PowerShell

Windows Command Prompt (CMD)

In CMD, the redirection syntax is identical to Unix-like systems:

unrar.exe x archive.rar > extraction.log 2>&1

Windows PowerShell

In PowerShell, use the following syntax to capture all output streams:

unrar.exe x archive.rar *>&1 | Out-File -FilePath extraction.log

Useful Flags for Silent and Automated Logging

When integrating unrar into automated scripts or cron jobs, combining your log command with additional switches creates clean, non-interactive log files:

  • -y: Assumes "yes" on all queries (such as overwrite prompts), preventing the process from hanging while waiting for user input.
  • -inul: Suppresses standard console messages, leaving only critical output.
  • -c-: Disables the archive comment display to minimize log bloat.

Example automated extraction command:

unrar x -y archive.rar > /var/log/unrar_job.log 2>&1