1 files changed, 33 insertions, 7 deletions
diff --git a/pkgs/profpatsch/execline/run-execline.nix b/pkgs/profpatsch/execline/run-execline.nix
index 40915f25..61c8c2e6 100644
--- a/pkgs/profpatsch/execline/run-execline.nix
+++ b/pkgs/profpatsch/execline/run-execline.nix
@@ -1,7 +1,12 @@
-{ stdenv, importasCommand, execlinebCommand }:
+{ stdenv, importasCommand, execCommand, redirfdCommand, execlinebCommand }:
 { name
-# the execline script
+# the execline script as string
 , execline
+# a string to pass as stdin to the execline script
+, stdin ? ""
+# a program wrapping the acutal execline invocation;
+# should be in Bernstein-chaining style
+, builderWrapper ? execCommand
 # additional arguments to pass to the derivation
 , derivationArgs ? {}
 }:
@@ -18,20 +23,41 @@ derivation (derivationArgs // {
 
   # okay, `builtins.toFile` does not accept strings
   # that reference drv outputs. This means we need
-  # to pass the script as envvar;
+  # to pass the script and stdin as envvar;
   # this might clash with another passed envar,
   # so we give it a long & unique name
   _runExeclineScript = execline;
-  passAsFile = [ "_runExeclineScript" ]
-            ++ derivationArgs.passAsFile or [];
+  _runExeclineStdin = stdin;
+  passAsFile = [
+    "_runExeclineScript"
+    "_runExeclineStdin"
+  ] ++ derivationArgs.passAsFile or [];
+
+  # the default, exec acts as identity executable
+  builder = builderWrapper;
 
-  builder = importasCommand;
   args = [
+    importasCommand          # import script file as $script
     "-ui"                    # drop the envvar afterwards
     "script"                 # substitution name
     "_runExeclineScriptPath" # passed script file
+
+    # TODO: can we scrap stdin via builderWrapper?
+    importasCommand          # do the same for $stdin
+    "-ui"
+    "stdin"
+    "_runExeclineStdinPath"
+
+    redirfdCommand           # now we
+    "-r"                     # read the file
+    "0"                      # into the stdin of execlineb
+    "$stdin"                 # that was given via stdin
+
     execlinebCommand         # the actual invocation
-    "-P"                     # ignore command line arguments
+    # TODO: depending on the use-case, -S0 might not be enough
+    # in all use-cases, then a wrapper for execlineb arguments
+    # should be added (-P, -S, -s).
+    "-S0"                    # set $@ inside the execline script
     "-W"                     # die on syntax error
     "$script"                # substituted by importas
   ];