Clamscan

Clamscan is a command-line scanner that is part of ClamAV, an open-source antivirus engine designed to detect trojans, viruses, and malware. It performs on-demand scans of files, directories, and archives using the local signature database. Clamscan supports scanning a wide range of formats, including compressed archives, and runs on multiple platforms such as Linux, Windows, and macOS.

Usage is typically clamscan [options] [path]. Common options include -r to scan directories recursively, -i to display only infected files, and -l to write a log file. The scanner reports per-file results and a final summary, relying on the ClamAV signatures which are updated by the separate freshclam utility. Clamscan can operate against the local database or through a clamd daemon for higher throughput in server environments.

Output generally consists of per-file status lines, such as file: OK for clean files or file: FOUND for infected ones, followed by a final summary of infected files and scanned items. Exit codes are used for scripting: exit status 0 indicates no infections were found, 1 indicates infections were detected, and 2 indicates an error occurred during scanning.

Clamscan is widely used for on-demand scanning on hosts and can be integrated into automated workflows, mail servers, and security pipelines as part of the ClamAV ecosystem. Its functionality is complemented by other tools in the ClamAV suite, such as clamd for daemon-based scanning and freshclam for signature updates.