tvl-depot/nix/escapeExecline/default.nix
Profpatsch 7a6a007302 refactor(nix/escapeExecline): move into own directory
The escaping functions are going to be used by both `writeExecline`
and `runExecline`, so let’s move them to their own namespace.

Change-Id: Iccf69eaeca3062573e0751a17c548b7def86196d
Reviewed-on: https://cl.tvl.fyi/c/depot/+/706
Reviewed-by: tazjin <mail@tazj.in>
Reviewed-by: Kane York <rikingcoding@gmail.com>
2020-06-29 22:58:32 +00:00

29 lines
1.1 KiB
Nix

{ lib, ... }:
let
# replaces " and \ to \" and \\ respectively and quote with "
# e.g.
# a"b\c -> "a\"b\\c"
# a\"bc -> "a\\\"bc"
escapeExeclineArg = arg:
''"${builtins.replaceStrings [ ''"'' ''\'' ] [ ''\"'' ''\\'' ] (toString arg)}"'';
# Escapes an execline (list of execline strings) to be passed to execlineb
# Give it a nested list of strings. Nested lists are interpolated as execline
# blocks ({}).
# Everything is quoted correctly.
#
# Example:
# escapeExecline [ "if" [ "somecommand" ] "true" ]
# == ''"if" { "somecommand" } "true"''
escapeExecline = execlineList: lib.concatStringsSep " "
(let
go = arg:
if builtins.isString arg then [(escapeExeclineArg arg)]
else if builtins.isPath arg then [(escapeExeclineArg "${arg}")]
else if lib.isDerivation arg then [(escapeExeclineArg arg)]
else if builtins.isList arg then [ "{" ] ++ builtins.concatMap go arg ++ [ "}" ]
else abort "escapeExecline can only hande nested lists of strings, was ${lib.generators.toPretty {} arg}";
in builtins.concatMap go execlineList);
in
escapeExecline