tvl-depot/nix/escapeExecline/default.nix

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{ 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