1 files changed, 12 insertions, 0 deletions
diff --git a/src/libexpr/primops.cc b/src/libexpr/primops.cc
index 2a96e25a8484..bb9190579af2 100644
--- a/src/libexpr/primops.cc
+++ b/src/libexpr/primops.cc
@@ -622,6 +622,17 @@ static Expr prim_dirOf(EvalState & state, const ATermVector & args)
 }
 
 
+/* Return the contents of a file as a string. */
+static Expr prim_readFile(EvalState & state, const ATermVector & args)
+{
+    PathSet context;
+    Path path = coerceToPath(state, args[0], context);
+    if (!context.empty())
+        throw EvalError(format("string `%1%' cannot refer to other paths") % path);
+    return makeStr(readFile(path));
+}
+
+
 /*************************************************************
  * Creating files
  *************************************************************/
@@ -968,6 +979,7 @@ void EvalState::addPrimOps()
     addPrimOp("__pathExists", 1, prim_pathExists);
     addPrimOp("baseNameOf", 1, prim_baseNameOf);
     addPrimOp("dirOf", 1, prim_dirOf);
+    addPrimOp("__readFile", 1, prim_readFile);
 
     // Creating files
     addPrimOp("__toXML", 1, prim_toXML);