* Allow '<nixexpr>' syntax to be used in nix-instantiate, nix-build

  and nix-env, e.g.,

  $ nix-env -f '<nixpkgs>' -i patchelf

  or

  $ nix-build '<nixos/tests>' -A login.test

2 files changed, 13 insertions, 0 deletions

diff --git a/src/libexpr/common-opts.cc b/src/libexpr/common-opts.cc
index d029d2ec35b9..e0865d9fcc25 100644
--- a/src/libexpr/common-opts.cc
+++ b/src/libexpr/common-opts.cc
@@ -44,4 +44,15 @@ bool parseSearchPathArg(const string & arg, Strings::iterator & i,
 }
 
 
+Path lookupFileArg(EvalState & state, string s)
+{
+    if (s.size() > 2 && s.at(0) == '<' && s.at(s.size() - 1) == '>') {
+        Path p = state.findFile(s.substr(1, s.size() - 2));
+        if (p == "") throw Error(format("file `%1%' was not found in the Nix search path (add it using $NIX_PATH or -I)") % p);
+        return p;
+    } else
+        return absPath(s);
+}
+
+
 }
diff --git a/src/libexpr/common-opts.hh b/src/libexpr/common-opts.hh
index 6b7247fc3d89..c28641e9015d 100644
--- a/src/libexpr/common-opts.hh
+++ b/src/libexpr/common-opts.hh
@@ -14,6 +14,8 @@ bool parseOptionArg(const string & arg, Strings::iterator & i,
 bool parseSearchPathArg(const string & arg, Strings::iterator & i,
     const Strings::iterator & argsEnd, EvalState & state);
 
+Path lookupFileArg(EvalState & state, string s);
+
 }