diff options
Diffstat (limited to 'nixos/lib')
| -rw-r--r-- | nixos/lib/utils.nix | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/nixos/lib/utils.nix b/nixos/lib/utils.nix index bbebf8ba35a..29135024195 100644 --- a/nixos/lib/utils.nix +++ b/nixos/lib/utils.nix @@ -45,6 +45,26 @@ rec { replaceChars ["/" "-" " "] ["-" "\\x2d" "\\x20"] (removePrefix "/" s); + # Quotes an argument for use in Exec* service lines. + # systemd accepts "-quoted strings with escape sequences, toJSON produces + # a subset of these. + # Additionally we escape % to disallow expansion of % specifiers. Any lone ; + # in the input will be turned it ";" and thus lose its special meaning. + # Every $ is escaped to $$, this makes it unnecessary to disable environment + # substitution for the directive. + escapeSystemdExecArg = arg: + let + s = if builtins.isPath arg then "${arg}" + else if builtins.isString arg then arg + else if builtins.isInt arg || builtins.isFloat arg then toString arg + else throw "escapeSystemdExecArg only allows strings, paths and numbers"; + in + replaceChars [ "%" "$" ] [ "%%" "$$" ] (builtins.toJSON s); + + # Quotes a list of arguments into a single string for use in a Exec* + # line. + escapeSystemdExecArgs = concatMapStringsSep " " escapeSystemdExecArg; + # Returns a system path for a given shell package toShellPath = shell: if types.shellPackage.check shell then |