X-Git-Url: http://plrg.eecs.uci.edu/git/?a=blobdiff_plain;f=folly%2FShell.h;h=0a58aa45da4c8a4ab4d3dfd4605f9838279ecae2;hb=c8aadaad37770dc4d1caf2bff239c604b51a6132;hp=56df3d278498dbd994bd2fe03f21fbe79a1beb2d;hpb=e69e359c24070c3b4ea2cd25f87b554e33b2a132;p=folly.git

diff --git a/folly/Shell.h b/folly/Shell.h
index 56df3d27..0a58aa45 100644
--- a/folly/Shell.h
+++ b/folly/Shell.h
@@ -1,5 +1,5 @@
 /*
- * Copyright 2016 Facebook, Inc.
+ * Copyright 2017 Facebook, Inc.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -27,6 +27,7 @@
 #include <string>
 #include <vector>
 
+#include <folly/Conv.h>
 #include <folly/Format.h>
 #include <folly/Range.h>
 
@@ -35,42 +36,58 @@ namespace folly {
 /**
  * Quotes an argument to make it suitable for use as shell command arguments.
  */
-std::string shellQuote(StringPiece argument) {
-  std::string quoted = "'";
-  for (auto c : argument) {
-    if (c == '\'') {
-      quoted += "'\\''";
-    } else {
-      quoted += c;
-    }
+std::string shellQuote(StringPiece argument);
+
+namespace detail {
+template <typename... Arguments>
+std::vector<std::string> shellify(
+    StringPiece format,
+    Arguments&&... arguments) {
+  auto command = sformat(
+      format,
+      shellQuote(to<std::string>(std::forward<Arguments>(arguments)))...);
+  return {"/bin/sh", "-c", command};
+}
+
+struct ShellCmdFormat {
+  StringPiece format;
+  template <typename... Arguments>
+  std::vector<std::string> operator()(Arguments&&... arguments) const {
+    return ::folly::detail::shellify(
+        format, std::forward<Arguments>(arguments)...);
   }
-  return quoted + "'";
+};
+
+} // namespace detail
+
+inline namespace literals {
+inline namespace shell_literals {
+constexpr detail::ShellCmdFormat operator"" _shellify(
+    char const* name,
+    std::size_t length) {
+  return {folly::StringPiece(name, length)};
 }
+} // inline namespace shell_literals
+} // inline namespace literals
 
 /**
   * Create argument array for `Subprocess()` for a process running in a
   * shell.
   *
-  * The shell to use is taken from the environment variable $SHELL,
-  * or /bin/sh if $SHELL is unset.
-  *
-  * The format string should always be a string literal to protect against
-  * shell injections. Arguments will automatically be escaped with `'`.
+  * The shell to use is always going to be `/bin/sh`.
   *
-  * TODO(dominik): find a way to ensure statically determined format strings.
+  * This is deprecated in favour of the user-defined-literal `_shellify`
+  * from namespace `folly::shell_literals` because that requires that the format
+  * string is a compile-time constant which can be inspected during code reviews
   */
 template <typename... Arguments>
+FOLLY_DEPRECATED(
+    "Use `\"command {} {} ...\"_shellify(argument1, argument2 ...)` from "
+    "namespace `folly::literals::shell_literals`")
 std::vector<std::string> shellify(
-    const StringPiece format,
+    StringPiece format,
     Arguments&&... arguments) {
-  const char* shell = getenv("SHELL");
-  if (!shell) {
-    shell = "/bin/sh";
-  }
-  auto command = sformat(
-      format,
-      shellQuote(to<std::string>(std::forward<Arguments>(arguments)))...);
-  return {shell, "-c", command};
+  return detail::shellify(format, std::forward<Arguments>(arguments)...);
 }
 
 } // folly