Spybar

Spybar is a Linux CLI utility that adds a progress bar to any tool reading a file. By example, it can create a progress bar for gzip, md5sum and other traditional utilities which don't display their progress.

Simply prefix any command with spybar.

Or, if the process is already running, attach using its PID. Suppose that you want to attach to process 42:

spybar -a 42

FAQ

Can you pipe it?

Yes you can, the progress bar happens on stderr

spybar gzip -c big_dump.sql > big_dump.sql.gz

Can it support Win/OSX?

Unfortunately there is no known way to do so. This utility relies on psutil's Process.open_files() abstraction so whenever this abstraction gives you the position for other platforms than Linux then Spybar will automatically work on those.

(By automatically I mean there is maybe a few adjustments needed on Unix-specific assumptions but it's most likely a just few lines to change).

How does it work?

If you navigate to the /proc file system you will see that for each process you not only get the list of open files (in /proc/XX/fd) but also meta-information about those files (in /proc/XX/fdinfo).

This way Spybar will look for files open in read mode by your process and then look at the current position of the file pointer, which once compared to the file size gives you the relative progress.

Does it always work?

Of course not, but the use case of binaries reading a file from the beginning to the end is fairly common. Who never waited in front of a gzip, xz, tar or md5sum wondering if they should go have a coffee or if it's just 2 seconds more?

In the end this is just guessing but it works in many situations.

Thanks

I would like to thank:

• Whomever put this feature in the Linux kernel
• The psutil maintainers
• The tqdm maintainers
• The poetry maintainers
• The pytest maintainers
• The apt maintainers from whom I stole the VT100 progress bar logic
• All open-source contributors thanks to whom this software was easy to write

License

This software is released under the terms of the WTFPL.