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syntax: printer breaks certain arithmetic expressions #987
Description
By default, shfmt removes brackets within parentheses, but this breaks certain kinds of expressions.
For example:
(( ! 0 )) && echo true || echo false # trueshfmt will format this into:
((!0)) && echo true || echo false # bash: !0: event not found
Activity
[-]Formatting breaks certain arithmetic expressions[/-][+]syntax: printer breaks certain arithmetic expressions[/+]mvdan commentedon Mar 25, 2023
Thanks for reporting - this does indeed look like a bug. Happy to review a PR, as this one shouldn't be hard to fix.
kiyoon commentedon Apr 15, 2023
I realised in zsh, the expression like this would be treated as
+operation and will make spaces in between, breaking the script.mikeBashStuff commentedon May 13, 2024
I believe this is only true for interactive shells since this syntax triggers history expansion. It's perfectly fine to use it from within a script by the very default, unless you explicitly enable
histexpand|historythere as well (which I guess is a valid use-case, though I personally prefer to trace the entire thing rather then save a history of it).mahadzaryab1 commentedon Aug 16, 2024
hi @mvdan ! i'm new to this project and to contributing to open-source in general. i would like to pick up this issue but am unsure of what needs to be done. would you be able to help me out with how to get started?
mdekstrand commentedon Jul 31, 2025
@mikeBashStuff It may only be a problem when history expansion is enabled, however, one of the major use cases for zsh support discussed in #120 — and likely also bash support — is to support formatting shell plugins, which will often run in an interactive shell.
syntax: add a printer test case for issue #987
syntax: print a space after "!" in arithmetic expressions