bash-core VS ShellCheck

Error handling is also atrocious. Doing set -e fixes some issues, but there are plenty of valid cases in which one of your commands will have an error, and your script will continue execution like nothing ever happened. And, in the case of an error, as I'm sure you have realized, diagnostics are absolutely terrible. You're extremely lucky to get a line number (which I think was only added since Bash 5.1), but that's it. If you want anything more, like a stacktrace, you're stuck in the water. I have developed a library, bash-core, to help with this, but the stacktrace handling acts unexpectedly if there are errors within subshells.

I'm quite happy to see that something Bash-related is on Hacker News! Unfortunately it seems that I don't really agree with much the author...

While I do agree that it would be nice to be able to have 'local' functions and have inter-function cleanup work better, the logical conclusion for me was not to use function subshells. Since the use case is for larger programs (where different functions may want to have their own cleanup mechanisms), I'm opting to go for more of a library route. For example, I'm working on a Bash library that includes a function to allow different sources to add (and remove) functions to the same `TRAP`. A similar function may be useful, possibly involving the `RETURN` trap and the `-T` flag. Obviously, using a package manager for _Bash_ of all languages brings in a lot of overhead, but I think it can be quite powerful, especially with a potential "Bundle" feature that makes scripts work without the package manager.

Concerning specifically the use of subshells, (as other commenters have pointed out) it significantly reduces performance. I also disagree that dynamic scoping is necessarily bad for Bash. I find it quite useful when I need to use various common functions to manipulate a variable - since modifying and 'returning' variables from a function is usually either slow or verbose with Bash. Admittedly though, this feature is quite annoying at times - for example, most public functions in my Bash package manager[2] all have their variables prefixed with two underscores - because they `source` all the shell scripts of all package dependencies - so I want to be extra certain nothing weird happens

[1] https://github.com/hyperupcall/bash-core/blob/a17ab0a8b6070f...

ncurse, dialog, zenity[2]. i/o buffering may be an issue [3a,3b]

Assuming using same account, use history command to show past commands[0a, 0b]

'load random example' on shellcheck using own custom examples from history command.[1]

--------

[3a] : http://www.gnu.org/software/coreutils/manual/html_node/stdbu...

[3b] : http://unix.stackexchange.com/questions/25372/how-to-turn-of...

[2] : http//funprojects.blog/2021/01/25/zenity-command-line-dialogs/

[1] : http://www.shellcheck.net/

[0a] : http://www.tecmint.com/history-command-examples/

[0b] : http://www.tecmint.com/remember-linux-commands/

web based documentation: https://www.tecmint.com/linux-commands-cheat-sheet/

commands grouped by typical usage patterns : https://www.tecmint.com/essential-linux-commands/

... #************************** Terraform ************************************* ARG TERRAFORM_VERSION=1.7.3 RUN set -ex \ && curl -O https://releases.hashicorp.com/terraform/${TERRAFORM_VERSION}/terraform_${TERRAFORM_VERSION}_linux_amd64.zip && unzip terraform_${TERRAFORM_VERSION}_linux_amd64.zip -d /usr/local/bin/ RUN set -ex \ && mkdir -p $HOME/.terraform.d/plugin-cache && echo 'plugin_cache_dir = "$HOME/.terraform.d/plugin-cache"' > ~/.terraformrc #************************* Terragrunt ************************************* ARG TERRAGRUNT_VERSION=0.55.1 RUN set -ex \ && wget https://github.com/gruntwork-io/terragrunt/releases/download/v${TERRAGRUNT_VERSION}/terragrunt_linux_amd64 -q \ && mv terragrunt_linux_amd64 /usr/local/bin/terragrunt \ && chmod +x /usr/local/bin/terragrunt #*********************** Terramate **************************************** ARG TERRAMATE_VERSION=0.4.5 RUN set -ex \ && wget https://github.com/mineiros-io/terramate/releases/download/v${TERRAMATE_VERSION}/terramate_${TERRAMATE_VERSION}_linux_x86_64.tar.gz \ && tar -xzf terramate_${TERRAMATE_VERSION}_linux_x86_64.tar.gz \ && mv terramate /usr/local/bin/terramate \ && chmod +x /usr/local/bin/terramate #*********************** tfsec ******************************************** ARG TFSEC_VERSION=1.28.5 RUN set -ex \ && wget https://github.com/aquasecurity/tfsec/releases/download/v${TFSEC_VERSION}/tfsec-linux-amd64 \ && mv tfsec-linux-amd64 /usr/local/bin/tfsec \ && chmod +x /usr/local/bin/tfsec \ && terragrunt --version #**********************Terraform docs ************************************ ARG TERRRAFORM_DOCS_VERSION=0.17.0 RUN set -ex \ && curl -sSLo ./terraform-docs.tar.gz https://terraform-docs.io/dl/v${TERRRAFORM_DOCS_VERSION}/terraform-docs-v${TERRRAFORM_DOCS_VERSION}-$(uname)-amd64.tar.gz \ && tar -xzf terraform-docs.tar.gz \ && chmod +x terraform-docs \ && mv terraform-docs /usr/local/bin/terraform-docs #********************* ShellCheck ***************************************** ARG SHELLCHECK_VERSION="stable" RUN set -ex \ && wget -qO- "https://github.com/koalaman/shellcheck/releases/download/${SHELLCHECK_VERSION?}/shellcheck-${SHELLCHECK_VERSION?}.linux.x86_64.tar.xz" | tar -xJv \ && cp "shellcheck-${SHELLCHECK_VERSION}/shellcheck" /usr/bin/ \ && shellcheck --version ...

ShellCheck: https://github.com/koalaman/shellcheck

If I want to write better shell scripts I usually run shellcheck and adjust accordingly or if I need facilities not provided by the shell i switch to a full fledged programming language. Ans oh yes, `sh` is present almost on every BSD and Linux box for free so I consider it an important thing to at least be comfortable with.

shellcheck: https://www.shellcheck.net/

When I run nix-shell at the root of the project it puts me in a Nix shell that contains, among other programs, caddy and shellcheck. Notice that in the shellHook I add the project's shell scripts to the PATH. So once I'm in the Nix shell I can, among other things:

I have also seen some projects on github like ShellCheck which first make a library, expose all the modules and then simple add that do build-depends of the final executable. Is this the recommended approach than having just one executable and adding all the modules to other-modules:?

The error checks can be pretty arcane:

   https://github.com/koalaman/shellcheck/wiki/Checks

Similar to for instance shellcheck to check the syntax of shell scripts, is there an equivalent for the set of roff commands typically used in a (Linux) man page? I'm aware that e.g. pandoc permits the conversion of an other format (e.g., org) to both roff man and roff ms.