Syntax error in docker zsh conditional command

Question

I'm trying to get a list of some deleted files in my git repo using a bash script. This however, needs to be run in a docker container and in a one liner.

I also want to only create the list of the files if there are actually any deleted files.

What I'm currently doing is:

[[ "$(git ls-files --deleted)" =~ "filename" ]] && git ls-files --deleted >! deleted_files.txt

Locally, this works fine. When I try in docker:

docker exec my-container bash -c "[[ $(git ls-files --deleted) =~ "filename" ]] && git ls-files --deleted >! deleted_files.txt"

I get this error, however:

bash: -c: line 0: conditional binary operator expected
bash: -c: line 0: syntax error near `filename'
bash: -c: line 0: `[[  =~ filename ]] && git ls-files --deleted >! deleted_files.txt'

My bash knowledge is extremely lacking, so there is a great chance I'm doing something wrong, but not exactly sure what.

Thanks in advance!

Think this is related with me using zsh. It's NOCLOBBER flag to let me overwrite the file if it exists. Which I do want. source: https://stackoverflow.com/questions/4676459/write-to-file-but-overwrite-it-if-it-exists#comment36200271_23585861 — pteixeira, Feb 21 '20 at 12:37

Arkadiusz Drabczyk · Accepted Answer · 2020-02-21T14:03:38.050

1

You have to run your command in single quotes. When Bash sees $variable in double quotes it expands it before running the command so what you get is =~ "filename". It should be:

docker exec my-container bash -c '[[ $(git ls-files --deleted) =~ "filename" ]] && git ls-files --deleted >! deleted_files.txt'

Also make sure you cd to the correct directory before running git ls-files.

If you want to use in Makefile you have to escape each $$ or you will get the same error as if you use double quotes. It could be:

docker exec gallant_stonebraker bash -c 'cd /all ; [[ $$(git ls-files --deleted) =~ "filename" ]] && git ls-files --deleted >! deleted_files.txt'

edited Feb 21 '20 at 14:03

answered Feb 21 '20 at 12:37

Arkadiusz Drabczyk

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probably dumb question, but is there any difference if this runs via Makefile? – pteixeira Feb 21 '20 at 13:36
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Yes, it would need Makefile escaping as well (`$$` instead of `$`) – that other guy Feb 21 '20 at 14:01
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@pteixeira: If you like this answer please mark it as solved to let other users know your problem is solved. Also see [What should I do when someone answers my question?](https://stackoverflow.com/help/someone-answers) – Arkadiusz Drabczyk Feb 22 '20 at 13:08

Syntax error in docker zsh conditional command

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