Add command running API

1 files changed, 255 insertions, 0 deletions

diff --git a/tests/command/driver.cxx b/tests/command/driver.cxx
new file mode 100644
index 0000000..a1baf68
--- /dev/null
+++ b/tests/command/driver.cxx
@@ -0,0 +1,255 @@
+// file      : tests/command/driver.cxx -*- C++ -*-
+// copyright : Copyright (c) 2014-2019 Code Synthesis Ltd
+// license   : MIT; see accompanying LICENSE file
+
+#include <cassert>
+
+#ifndef __cpp_lib_modules
+#include <ios>
+#include <string>
+#include <vector>
+#include <iostream>
+#include <stdexcept> // invalid_argument
+#endif
+
+// Other includes.
+
+#ifdef __cpp_modules
+#ifdef __cpp_lib_modules
+import std.core;
+import std.io;
+#endif
+import butl.path;
+import butl.path_io;
+import butl.process; // process::print()
+import butl.command;
+import butl.utility;
+import butl.optional;
+#else
+#include <libbutl/path.mxx>
+#include <libbutl/path-io.mxx>
+#include <libbutl/process.mxx>
+#include <libbutl/command.mxx>
+#include <libbutl/utility.mxx>
+#include <libbutl/optional.mxx>
+#endif
+
+using namespace std;
+using namespace butl;
+
+// Usages:
+//
+// argv[0] [-d <dir>] [-v <name>[=<value>]] [-s <name>=<value>] [-c <char>]
+//         [-p] <command>
+//
+// argv[0] -C [-A] [-D] [-V <name>] [-S <status>] <arguments>
+//
+// In the first form run the specified command, changing the current
+// directory, (re)setting the environment variables, performing substitutions,
+// and printing the "expanded" command line, if requested.
+//
+// In the second form optionally print the program arguments, CWD, the
+// environment variable values and exit with the status specified. This mode
+// is normally used for the command being tested to dump the environment
+// obtained from the caller.
+//
+// -d <dir>
+//    Change the CWD for the command process.
+//
+// -v <name>[=<value>]
+//    (Un)set the environment variable for the command process. Can be
+//    specified multiple times.
+//
+// -s <name>=<value>
+//    Perform command line substitutions using the specified variable. Can be
+//    specified multiple times.
+//
+// -c <char>
+//    Substitution symbol. The default is '@'.
+//
+// -p
+//    Print the "expanded" command line.
+//
+// -C
+//    Print the program arguments (-A), CWD (-D), environment variables (-V)
+//    to stdout and exit with the status specifies (-S).
+//
+// -A
+//    Print the program arguments to stdout.
+//
+// -D
+//    Print the process CWD to stdout.
+//
+// -V <name>
+//    Print the environment variable value (or <unset>) to stdout. Can be
+//    specified multiple times.
+//
+// -S <status>
+//    Exit with the specified status code.
+//
+int
+main (int argc, const char* argv[])
+{
+  using butl::optional;
+  using butl::getenv;
+
+  // Parse and validate the arguments.
+  //
+  dir_path cwd;
+  vector<const char*> vars;
+  optional<command_substitution_map> substitutions;
+  char subst ('@');
+  optional<string> command;
+  bool print (false);
+
+  for (int i (1); i != argc; ++i)
+  {
+    string o (argv[i]);
+
+    if (o == "-d")
+    {
+      assert (++i != argc);
+      cwd = dir_path (argv[i]);
+    }
+    else if (o == "-v")
+    {
+      assert (++i != argc);
+      vars.push_back (argv[i]);
+    }
+    else if (o == "-s")
+    {
+      assert (++i != argc);
+
+      if (!substitutions)
+        substitutions = command_substitution_map ();
+
+      string v (argv[i]);
+      size_t p (v.find ('='));
+
+      assert (p != string::npos && p != 0);
+
+      (*substitutions)[string (v, 0, p)] = string (v, p + 1);
+    }
+    else if (o == "-c")
+    {
+      assert (++i != argc);
+
+      string v (argv[i]);
+
+      assert (v.size () == 1);
+      subst = v[0];
+    }
+    else if (o == "-p")
+    {
+      print = true;
+    }
+    else if (o == "-C")
+    {
+      assert (i == 1); // Must go first.
+
+      int ec (0);
+      bool print_cwd (false);
+
+      // Include the program path into the arguments list.
+      //
+      vector<const char*> args ({argv[0]});
+
+      for (++i; i != argc; ++i)
+      {
+        o = argv[i];
+
+        if (o == "-A")
+        {
+          print = true;
+        }
+        else if (o == "-D")
+        {
+          print_cwd = true;
+        }
+        else if (o == "-V")
+        {
+          assert (++i != argc);
+          vars.push_back (argv[i]);
+        }
+        else if (o == "-S")
+        {
+          assert (++i != argc);
+          ec = stoi (argv[i]);
+        }
+        else
+          args.push_back (argv[i]);
+      }
+
+      args.push_back (nullptr);
+
+      if (print)
+      {
+        process::print (cout, args.data ());
+        cout << endl;
+      }
+
+      if (print_cwd)
+        cout << dir_path::current_directory () << endl;
+
+      for (const auto& v: vars)
+      {
+        optional<string> vv (getenv (v));
+        cout << (vv ? *vv : "<unset>") << endl;
+      }
+
+      return ec;
+    }
+    else
+    {
+      assert (!command);
+      command = argv[i];
+    }
+  }
+
+  assert (command);
+
+  // Run the command.
+  //
+  try
+  {
+    optional<process_env> pe;
+
+    if (!cwd.empty () || !vars.empty ())
+      pe = process_env (process_path (), cwd, vars);
+
+    process_exit e (command_run (*command,
+                                 pe,
+                                 substitutions,
+                                 subst,
+                                 [print] (const char* const args[], size_t n)
+                                 {
+                                   if (print)
+                                   {
+                                     process::print (cout, args, n);
+                                     cout << endl;
+                                   }
+                                 }));
+
+    if (!e)
+      cerr << "process " << argv[0] << " " << e << endl;
+
+    return e.normal () ? e.code () : 1;
+  }
+  catch (const invalid_argument& e)
+  {
+    cerr << e << endl;
+    return 1;
+  }
+  catch (const ios::failure& e)
+  {
+    cerr << e << endl;
+    return 1;
+  }
+  catch (const process_error& e)
+  {
+    cerr << e << endl;
+    return 1;
+  }
+
+  return 0;
+}