Guess update information based on GitHub Actions environment variables

[srevinsaju]

Reads the GITHUB_REPOSITORY and GITHUB_REF environment variables
and attempts to generate an appropriate updateinformation

Adapted from https://github.com/probonopd/go-appimage/blob/7fab45552eb485c0076fd310835fa7958f981de0/src/appimagetool/appimagetool.go\#L547-L567

Sample run

github@fbfcaab3b211:~/build/out$ export GITHUB_REPOSITORY='probonopd/Zoom.AppImage'
github@fbfcaab3b211:~/build/out$ appimagetool appimagetool.AppDir/ -g             
appimagetool, continuous build (commit 0880085), build <local dev build> built on 2020-09-09 20:44:40 UTC
WARNING: appstreamcli command is missing, please install it if you want to use AppStream metadata
NOTE: Using the output of 'git rev-parse --short HEAD' as the version:
      0880085
      Please set the $VERSION environment variable if this is not intended
Using architecture x86_64
/home/github/build/out/appimagetool.AppDir should be packaged as appimagetool-0880085-x86_64.AppImage
AppStream upstream metadata found in usr/share/metainfo/appimagetool.appdata.xml
Generating squashfs...
Parallel mksquashfs: Using 8 processors
Creating 4.0 filesystem on appimagetool-0880085-x86_64.AppImage, block size 131072.
[========================================================================================/] 19/19 100%

Exportable Squashfs 4.0 filesystem, gzip compressed, data block size 131072
        compressed data, compressed metadata, compressed fragments,
        compressed xattrs, compressed ids
        duplicates are removed
Filesystem size 461.61 Kbytes (0.45 Mbytes)
        39.67% of uncompressed filesystem size (1163.54 Kbytes)
Inode table size 317 bytes (0.31 Kbytes)
        39.33% of uncompressed inode table size (806 bytes)
Directory table size 319 bytes (0.31 Kbytes)
        56.36% of uncompressed directory table size (566 bytes)
Number of duplicate files found 2
Number of inodes 24
Number of files 12
Number of fragments 2
Number of symbolic links  0
Number of device nodes 0
Number of fifo nodes 0
Number of socket nodes 0
Number of directories 12
Number of ids (unique uids + gids) 1
Number of uids 1
        root (0)
Number of gids 1
        root (0)
Embedding ELF...
Marking the AppImage as executable...
Running on GitHub Actions
Guessing update information based on $GITHUB_REPOSITORY=probonopd/Zoom.AppImage and $GITHUB_REF=refs/heads/featureA
gh-releases-zsync|probonopd|Zoom.AppImage|continuous|appimagetool*-x86_64.AppImage.zsync
Embedding MD5 digest
zsyncmake is available and updateinformation is provided, hence generating zsync file
Success

Please consider submitting your AppImage to AppImageHub, the crowd-sourced
central directory of available AppImages, by opening a pull request
at https://github.com/AppImage/appimage.github.io
github@fbfcaab3b211:~/build/out$

[srevinsaju]

@probonopd this is my first C lang based PR, so please let me know of corrections

[TheAssassin]

The idea is okay, but the implementation needs to be improved. I commented on most of the problems. Please fix, I'll re-review then.

[srevinsaju]

@TheAssassin I guess I fixed the issues which you mentioned. Please review again.

[LautaroLobo12]

LGTM!

[srevinsaju]

@TheAssassin if you have few minutes to spare, could you please review this merge request, so that I can update accordingly? Thanks!!

[TheAssassin]

Noted the most important problems. Will re-check when those are fixed.

[probonopd]

Hello @srevinsaju do you think you can address the points raised by @TheAssassin and @codewiz above? I'd really like to see this merged for probonopd/Zoom.AppImage#1.

[srevinsaju]

I am having my first semester starting from tomorrow 🥶 , apologize for the delay. I would try to finish it as soon as the exams finish 🥇

its growing white 😅

[srevinsaju]

This "constant" is irrelevant to the rest of the file. Also, the code doesn't use such a convention anyway.

@TheAssassin so you mean, I should not use a constant? and keep literals, or move the constant a bit more down?

[TheAssassin]

A static const int is sufficient.

[srevinsaju]

A static const int is sufficient.

At the same position where it is, right?

[TheAssassin]

Obviously not. You should place it before the first use.

[srevinsaju]

Obviously not. You should place it before the first use.

ok, got it!

[srevinsaju]

@TheAssassin I hope I fixed all of what you have mentioned above.
This Pull Request was a great opportunity to learn more about C, and how dangerous it can be, if not used properly. Thanks to @codewiz.

This makes me think about using more safer languages like Rust, or at least modern C++.

@TheAssassin kindly review

[probonopd]

This makes me think about using more safer languages

Like Golang? Reminds me of probonopd/go-appimage#99 :)

[srevinsaju]

Yea GoLang can be considered as a safe language too. I am interested in v2 of GoLang, its more interesting 🚀

If I go by preference of languages:

1. Rust (new language for me, static binaries, super fast)
2. GoLang (easy to code, understand, functional)
3. C++ (20?)

[probonopd]

Reference: probonopd/linuxdeployqt#316

[yozachar]

Hi, is the PR still maintained? It's says this branch is out-of date with the base, I'd like to see this feature, how can I help? Coming from probonopd/Zoom.AppImage#1

[srevinsaju]

Hi, is the PR still maintained? It's says this branch is out-of date with the base, I'd like to see this feature, how can I help?

Updated.

[probonopd]

Thanks for updating @srevinsaju.

Hello @TheAssassin

Noted the most important problems. Will re-check when those are fixed.

Would be great if you could re-check if you find the time. I think this would be valuable to get merged soon.

Thanks!