lastb

Additional Notes

lastb is a security command used to show failed login attempts. It reads from /var/log/btmp to display a record of failed authentication attempts.

lastb typically requires root access to read /var/log/btmp. It is useful for detecting brute-force attacks or unauthorized access attempts.

Syntax

lastb [options] [arguments]

Parameters

• options: Flags that change how lastb behaves.
• target: File, user, service, policy, or security object to inspect or modify.
• value: Security setting, context, key, hash, or policy value.

Common Options

• --help: Show command help when supported.
• --version: Show version information when supported.

Examples

lastb --help
man lastb

Practical Notes

Options can vary by distribution and package version. Use man lastb, lastb --help, or the package documentation for exact syntax.