Unrar Password Prompting Without the -p Flag

The unrar command-line utility natively supports interactive password prompts when processing encrypted RAR archives without the -p flag. By default, whenever unrar encounters an archive with encrypted content or encrypted headers and no password has been supplied beforehand, it halts execution to securely request the credentials from the user via standard input. This behavior ensures that sensitive archives can be extracted without exposing credentials in plaintext terminal history or process listings.

Default Prompting Behavior

When you execute extraction commands such as unrar e archive.rar or unrar x archive.rar on an encrypted file without specifying -p, the utility detects the encryption layer and pauses execution. It then outputs the following prompt:

Enter password (will not be echoed):

Keystrokes are masked to prevent shoulder surfing, and pressing Enter submits the password to continue the extraction process.

Encrypted Headers vs. Encrypted File Data

The exact moment the password prompt appears depends on how the archive was created:

  • Encrypted File Names (Encrypted Headers): If the archive was created with the encrypt headers option (-hp), unrar cannot read the list of files inside the archive. It will display the password prompt immediately before listing or extracting any contents.
  • Encrypted Data Only: If only the file contents are encrypted, unrar can read the archive's metadata and file list without authentication. It will display the file list first, prompting for the password only when it begins extracting the first encrypted file.

Controlling Password Prompts

While interactive prompting is the default, specific flags can alter this behavior:

  • Suppressing Prompts (-p-): If you run automated scripts or cron jobs, interactive prompts can cause processes to hang indefinitely waiting for input. Passing -p- instructs unrar not to ask for a password. If a password is required, the operation immediately fails or skips the protected files.
  • Supplying Passwords Inline (-p<password>): Specifying the password directly with the flag (for example, -pMySecret) bypasses the prompt entirely. While useful for automation, this method can expose passwords in shell histories, log files, and process tables (ps).

Omitting the -p flag remains the recommended method for interactive, secure terminal usage across Linux, macOS, and Windows environments.