tvl-depot/users/Profpatsch/lib.nix
Vincent Ambo aa122cbae7 style: format entire depot with nixpkgs-fmt
This CL can be used to compare the style of nixpkgs-fmt against other
formatters (nixpkgs, alejandra).

Change-Id: I87c6abff6bcb546b02ead15ad0405f81e01b6d9e
Reviewed-on: https://cl.tvl.fyi/c/depot/+/4397
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
Reviewed-by: lukegb <lukegb@tvl.fyi>
Reviewed-by: wpcarro <wpcarro@gmail.com>
Reviewed-by: Profpatsch <mail@profpatsch.de>
Reviewed-by: kanepyork <rikingcoding@gmail.com>
Reviewed-by: tazjin <tazjin@tvl.su>
Reviewed-by: cynthia <cynthia@tvl.fyi>
Reviewed-by: edef <edef@edef.eu>
Reviewed-by: eta <tvl@eta.st>
Reviewed-by: grfn <grfn@gws.fyi>
2022-01-31 16:11:53 +00:00

108 lines
2.8 KiB
Nix

{ depot, pkgs, ... }:
let
bins = depot.nix.getBins pkgs.coreutils [ "printf" "echo" "cat" "printenv" "tee" ]
// depot.nix.getBins pkgs.bash [ "bash" ]
// depot.nix.getBins pkgs.fdtools [ "multitee" ]
;
# Print `msg` and and argv to stderr, then execute into argv
debugExec = msg: depot.nix.writeExecline "debug-exec" { } [
"if"
[
"fdmove"
"-c"
"1"
"2"
"if"
[ bins.printf "%s: " msg ]
"if"
[ bins.echo "$@" ]
]
"$@"
];
# Print stdin to stderr and stdout
eprint-stdin = depot.nix.writeExecline "eprint-stdin" { } [
"pipeline"
[ bins.multitee "0-1,2" ]
"$@"
];
# Assume the input on stdin is netencode, pretty print it to stderr and forward it to stdout
eprint-stdin-netencode = depot.nix.writeExecline "eprint-stdin-netencode" { } [
"pipeline"
[
# move stdout to 3
"fdmove"
"3"
"1"
# the multitee copies stdin to 1 (the other pipeline end) and 3 (the stdout of the outer pipeline block)
"pipeline"
[ bins.multitee "0-1,3" ]
# make stderr the stdout of pretty, merging with the stderr of pretty
"fdmove"
"-c"
"1"
"2"
depot.users.Profpatsch.netencode.pretty
]
"$@"
];
# print the given environment variable in $1 to stderr, then execute into the rest of argv
eprintenv = depot.nix.writeExecline "eprintenv" { readNArgs = 1; } [
"ifelse"
[ "fdmove" "-c" "1" "2" bins.printenv "$1" ]
[ "$@" ]
"if"
[ depot.tools.eprintf "eprintenv: could not find \"\${1}\" in the environment\n" ]
"$@"
];
# Split stdin into two commands, given by a block and the rest of argv
#
# Example (execline):
#
# pipeline [ echo foo ]
# split-stdin [ fdmove 1 2 foreground [ cat ] echo "bar" ] cat
#
# stdout: foo\n
# stderr: foo\nbar\n
split-stdin = depot.nix.writeExecline "split-stdin" { argMode = "env"; } [
"pipeline"
[
# this is horrible yes but the quickest way I knew how to implement it
"runblock"
"1"
bins.bash
"-c"
''${bins.tee} >("$@")''
"bash-split-stdin"
]
"runblock"
"-r"
"1"
];
# remove everything but a few selected environment variables
runInEmptyEnv = keepVars:
let
importas = pkgs.lib.concatMap (var: [ "importas" "-i" var var ]) keepVars;
# we have to explicitely call export here, because PATH is probably empty
export = pkgs.lib.concatMap (var: [ "${pkgs.execline}/bin/export" var ''''${${var}}'' ]) keepVars;
in
depot.nix.writeExecline "empty-env" { }
(importas ++ [ "emptyenv" ] ++ export ++ [ "${pkgs.execline}/bin/exec" "$@" ]);
in
{
inherit
debugExec
eprint-stdin
eprint-stdin-netencode
eprintenv
split-stdin
runInEmptyEnv
;
}