pipe-timestamper.py

#!/usr/bin/env python3
# Author: github.com/danielhoherd
# License: MIT
"""Takes a stream from stdin and prefixes it with the timestamp it was read and
the delta from the previous line.

Most useful for slow streams.
"""

from sys import argv, stdin

import pendulum
import typer


def timestamp_lines(show_delta: bool = typer.Option(None, help="Show the time delta between each line.")):
    """Takes a stream from stdin and prefixes it with the timestamp it was read
    and the delta from the previous line.

    Most useful for slow streams.
    """

    old = pendulum.now()

    if stdin.isatty():
        print(f"Description: {__doc__}")
        print(f"Usage: <some_command> | {argv[0]}")
        raise SystemExit(1)
    for line in stdin:
        line = line.strip("\n")
        new = pendulum.now()
        delta = (new - old).in_words()
        if show_delta:
            print(f"{new.to_iso8601_string()} ({delta}) {line}")
        else:
            print(f"{new.to_iso8601_string()} {line}")
        old = new


if __name__ == "__main__":
    typer.run(timestamp_lines)