flow

Run a flow check

$ flow

$ flow ls

$ flow batch-coverage --show-all --strip-root [path/to/directory]

$ flow coverage --color [path/to/file.jsx]

flow-print [OPTIONS] [FILES...]

-f
    Specifies a custom output format file for flow records.

-F
    Uses a predefined output format tag (e.g., 'compact', 'long').

-m
    Includes milliseconds in timestamps for more precise timing.

-o
    Writes the decoded flow output to the specified file instead of standard output.

-s
    Sorts output by comma-separated fields, e.g., 'srcip,dstip'.

-t
    Defines the timestamp output format (e.g., 'iso', 'unix').

-x
    Prints extended or verbose output for each flow record.

-v
    Increases verbosity level, showing more operational details.


    One or more input flow files to process. If omitted, reads from standard input.

The command "flow" is not a standard, standalone Linux command.

However, "flow" is widely used to refer to network flow data, such as NetFlow, IPFIX, and sFlow, which are protocols used for collecting IP traffic information. In the Linux ecosystem, handling this data typically involves specialized tool suites like flow-tools or nfdump.

This analysis describes flow-print, a prominent utility from the flow-tools suite, which is commonly used to decode and display captured network flow records. It serves as a representative example of how "flow" data is processed and presented on Linux systems.

The command "flow" itself is not a standalone executable in most standard Linux distributions. The information provided here describes flow-print, a specific command from the flow-tools suite, which is a common set of utilities for handling network flow data. Users should install the flow-tools package to use flow-print.

Network flow data represents aggregated records of network communication, rather than raw packet data. Each record typically includes source/destination IP addresses, ports, protocol, timestamps, and byte/packet counts for a specific flow. This high-level summary is invaluable for network monitoring, security analysis (e.g., detecting anomalies or DDoS attacks), billing, and capacity planning, as it provides insights into "who communicated with whom, when, and how much data was exchanged."

The flow-tools suite, from which flow-print originates, was developed to collect, process, and analyze NetFlow data. NetFlow, originally a Cisco-specific protocol, became a de facto standard for network traffic monitoring. The flow-tools project provided essential open-source utilities for working with these flow records outside of proprietary solutions, evolving with various NetFlow versions and later IPFIX (IP Flow Information Export). Its development peaked in the early 2000s, offering robust command-line tools for network administrators and security analysts to gain insights into network traffic patterns.

nfdump(1), flow-capture(1), sflowtool(1)