Support using stdin for arguments that take files in cross-platform agnostic way

[worstje]

(First of all: yes, I know that Unix-alikes has /dev/stdin that can serve as a file-like standin. That's useless to me when using Windows which lacks such a thing entirely.)

Introduction / Context

Most workflows tend to be born out of necessity. You code something, you make it work, and (assuming they are a regular part of your workflow) you rewrite parts every few months as you come across new requirements or edge cases. That is how I have ended up with a folder of Python scripts that rely on pandoc for a considerable number of manipulations that are mostly quite specific to the scripts themselves. Most of these have accompanying template and/or filter files, but you can imagine that has gotten quite chaotic, especially with some files having become outright abandoned as my needs changed.

Themselves, they are not a pandoc 'problem' at all, but it made me realize that having these parts of the process in separate files is often detrimental a few months down the road in understanding what is actually going on. (I have plenty of comments in my Python code, but those rarely cover the questions I have when something involving pandoc doesn't work quite right!)

Without such means, one way I could 'clean up' this aspect during my upcoming improvement work is by writing a temporary file with the intended filter for every invocation... but that is an unneeded performance hit. Or I could just do nothing at all and keep hating myself every time I have to dig into one of those scripts...

The request

It would be nice if, for commandline arguments that accept a file from the filesystem, there was some sort of cross-platform syntax that would make it read that parameter from standard input.

I realize that there is only one stdin which would limit this functionality to being used in just one argument at a time, but since that covers over half of my script-based pandoc invocations, so it would still make a considerable impact for me personally.

However...

If nobody else sees a use for such a feature, feel free to throw this request in the digital bin. Never before have I been accused of being a user matching the common stereotypes. 😸

[mb21]

I'd guess this is indeed out of scope... most people tend to just have a bash file in that folder, or use the new defaults files or something like panrun... but not exactly sure what your workflow is..

[worstje]

Assuming you are mentioning bash for the sake of a cygwin-esque environment that simulates /dev/stdin, I don't think that's anywhere close to a dependency I'd want given that my purpose is to remove maintenance complexity.

Defaults files I wasn't aware of, but it doesn't seem like they'll change anything. I'll just end up with even more files to look through and grasp than I already do now. Sames seems to go for panrun.

The general gist of the scripts comes down to homebrew reporting of all sorts of things that tap into various sources of relevance through Python.

All I am hoping for is an os-agnostic way to say 'read this data-file from stdin' of which the impact is smaller than writing temporary files like I am already considering. Spinning up a cygwin-esque environment to provide a pipe is definitely going to be heavier. Programs having to implement alternative workarounds for the lack of /dev/stdin on Windows is definitely a thing.

Some linux commands use a dash (-) to mean that very same thing, although I am not sure that applies to --arguments in particular.

Regardless, don't worry about it. It was just a shot in the dark. Happy holidays! 😄

[jgm]

I'm not sure it's out of scope. There are some cli utilities that adopt the convention that - as a filename = stdin. If we did that, it would make things simpler cross-platform, so it's worth considering.

[tarleb]

FWIW, I'm in favor of the proposed change. There are projects, e.g. EMBOSS, which use stdin as a special filename; but - seems much more common.

[jgm]

It would be nice if, for commandline arguments that accept a file from the filesystem, there was some sort of cross-platform syntax that would make it read that parameter from standard input.

I assume you don't mean the input files, since you can just run pandoc with no input files and it will read from stdin. You mean arguments like --include-in-header, I guess? Can you give an example where you'd want to populate something like that from stdin?

[jgm]

Note: - as an alias for stdin already works with input files and with -o.