cmake: Add '-E sleep' command

Add a cmake command-line interface to provide a cross-platform 'sleep'.

Help/manual/cmake.1.rst

@@ -39,7 +39,7 @@ Options
  that can be used on all systems.  Run with -E help for the usage
  information.  Commands available are: chdir, compare_files, copy,
  copy_directory, copy_if_different, echo, echo_append, environment,
- make_directory, md5sum, remove, remove_directory, rename, tar, time,
+ make_directory, md5sum, remove, remove_directory, rename, sleep, tar, time,
  touch, touch_nocreate.  In addition, some platform specific commands
  are available.  On Windows: delete_regv, write_regv.  On
  UNIX: create_symlink.

Source/cmcmd.cxx

@@ -71,6 +71,7 @@ void CMakeCommandUsage(const char* program)
        "(on one volume)\n"
     << "  tar [cxt][vfz][cvfj] file.tar [file/dir1 file/dir2 ...]\n"
     << "                            - create or extract a tar or zip archive\n"
+    << "  sleep <number>...         - sleep for given number of seconds\n"
     << "  time command [args] ...   - run command and return elapsed time\n"
     << "  touch file                - touch a file.\n"
     << "  touch_nocreate file       - touch a file but do not create it.\n"
@@ -279,6 +280,33 @@ int cmcmd::ExecuteCMakeCommand(std::vector<std::string>& args)
       return 0;
       }
 
+    // Sleep command
+    else if (args[1] == "sleep" && args.size() > 2)
+      {
+      double total = 0;
+      for(size_t i = 2; i < args.size(); ++i)
+        {
+        double num = 0.0;
+        char unit;
+        char extra;
+        int n = sscanf(args[i].c_str(), "%lg%c%c", &num, &unit, &extra);
+        if((n == 1 || (n == 2 && unit == 's')) && num >= 0)
+          {
+          total += num;
+          }
+        else
+          {
+          std::cerr << "Unknown sleep time format \"" << args[i] << "\".\n";
+          return 1;
+          }
+        }
+      if(total > 0)
+        {
+        cmSystemTools::Delay(static_cast<unsigned int>(total*1000));
+        }
+      return 0;
+      }
+
     // Clock command
     else if (args[1] == "time" && args.size() > 2)
       {

Tests/RunCMake/CommandLine/E_sleep-bad-arg1-result.txt

@@ -0,0 +1 @@
+1

Tests/RunCMake/CommandLine/E_sleep-bad-arg1-stderr.txt

@@ -0,0 +1 @@
+^Unknown sleep time format "x"\.$

Tests/RunCMake/CommandLine/E_sleep-bad-arg2-result.txt

@@ -0,0 +1 @@
+1

Tests/RunCMake/CommandLine/E_sleep-bad-arg2-stderr.txt

@@ -0,0 +1 @@
+^Unknown sleep time format "-1"\.$

Tests/RunCMake/CommandLine/E_sleep-no-args-result.txt

@@ -0,0 +1 @@
+1

Tests/RunCMake/CommandLine/E_sleep-no-args-stderr.cmake

@@ -0,0 +1,2 @@
+Usage: .*/cmake -E \[command\] \[arguments \.\.\.\]
+Available commands:

Tests/RunCMake/CommandLine/RunCMakeTest.cmake

@@ -23,3 +23,8 @@ if(UNIX)
     ${CMAKE_COMMAND} -E create_symlink T .
     )
 endif()
+
+run_cmake_command(E_sleep-no-args ${CMAKE_COMMAND} -E sleep)
+run_cmake_command(E_sleep-bad-arg1 ${CMAKE_COMMAND} -E sleep x)
+run_cmake_command(E_sleep-bad-arg2 ${CMAKE_COMMAND} -E sleep 1 -1)
+run_cmake_command(E_sleep-one-tenth ${CMAKE_COMMAND} -E sleep 0.1)