On 2021-03-20 13:13, pkill9 wrote:
I would like to be able to pipe files into guix commands.
Specifically the `guix system build` command, so I can build a system
configuration on a remote Guix system over SSH, i.e. `cat config.scm |
ssh <remote-system> guix system build -`, or perhaps using the
`--expression` flag which would make more sense, e.g. `cat config.scm |
ssh <remote-system> guix system build -e -`.
While you can currently just copy over a file and then use that, it
would be a little cleaner and more stateless to use a pipe.
What do other people think?
I like pipes and this would be nice to have. Though an easy way to wrap
things in bash and make them pipable at the same time is to use the -t
check like this:
f(){ [[ ! -t 0 ]] && mapfile -t Args ; if [[ -n "${Args[@]}" ]]; then
printf 'some_command %s ' "${Args[@]}" ; else printf 'some_command %s '
"$@"; fi ; }
printf '%s\n' a b c | f
f a b c
So you could define f as: f(){ [[ ! -t 0 ]] && mapfile -t -d '' Args ;
if [[ -n "${Args[@]}" ]]; then ssh <remote-system> guix system build -e
"${Args[@]//$'\n'/}" ; else ssh <remote-system> guix system build -e
"$@"; fi ; }
and then I think you should be able to cat config.scm | f
Notice -d '' above which means use null as delimiter which will most
often put everything in index 0 of the list. Also notice the parameter
expansion which removes all newlines from the content.
I do agree though that it would be nicer to just have '-' as a guix
input arg causing any guix command to read from stdin.
I hope it helps!
Best regards,
David