[sieste]

Due to pdf popularity there is a lot of demand for pdf processing tools. And the format is so complex that there are many nontrivial and creative ways to do pdf processing. That's why these "Hello World" projects usually make Top 5 on HN, and one of the upvotes is usually from me.

[forgotpwd16]

>many nontrivial and creative ways to do pdf processing

They're all wrapping PDFlib and provide the same functionality.

[sam_lowry_]

I am already well served by ghostscript, GIMP, Imagemagick, etc:

Optimize PDF:

    #!/bin/bash
    INPUT="$1"
    OUTPUT="$(mktemp --suffix=.pdf)"
    gs -sDEVICE=pdfwrite -dCompatibilityLevel=1.4 -dPDFSETTINGS=/ebook \
    -dNOPAUSE -dQUIET -dBATCH -sOutputFile="$OUTPUT" "$INPUT"
    mv "$OUTPUT" "$INPUT"

Merge PDF:

    #!/bin/sh
    gs -q -dNOPAUSE -dBATCH -sDEVICE=pdfwrite \
      -dCompatibilityLevel=1.3 -dPDFSETTINGS=/ebook \
      -sOutputFile=merged.pdf "$@"

And so on and so forth.

Moreover, I see a webapp and I immediately assume everything I do in this app is exfiltrated and abused.

I can check that the webapp advertised above is indeed local-first, but I can't be 100% sure they don't steal my data in a way I did not foresee, e.g. via websockets or cookies.

Because I learnt this the hard way by being on Instagram and Gmail.