How to automatically respond to confirmations in CLI tools
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Recently, we released a new CLI tool to migrate data in Contentful. It's currently in beta and we'll work on it to make it better.
Last week we received a question in our community forum. A user asked if he could use the CLI programmatically. He had the problem that the CLI asks at some point for confirmation and this makes it hard to run in a CI environment.
? Do you want to apply the migration? (Y/n)
How could you answer this question when it's not you running this command but a potential CI environment.
My colleage Stephan had a cool solution. He responded that the unix command yes
could help out here. yes
? What kind of command is that?
The man page for yes
is not giving much information but according to [Wikipedia](https://en.wikipedia.org/wiki/Yes_(Unix) this is what it does:
By itself, the yes command outputs 'y' or whatever is specified as an argument, followed by a newline repeatedly until stopped by the user or otherwise killed; when piped into a command, it will continue until the pipe breaks (i.e., the program completes its execution).
When you execute yes sunshine
this is what you'll get:
$ yes sunshine
sunshine
sunshine
sunshine
sunshine
sunshine
...
A lot of sunshine! ☀️
Use it to combine yes
with other CLI commands and auto-respond to confirmations.
$ yes Y | contentful-migration --space-id xxx migration.js
There is another way to answer confirmation in a CLI automatically, though. It turns out, you can also echo
and pipe a string into another command.
$ echo yes | contentful-migration --space-id xxx migration.js
I think that's pretty cool stuff and it will definitely help me for my next automation tasks!
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