ENH: add a touch -E command to cmake

Source/cmake.cxx

@@ -941,6 +941,8 @@ void CMakeCommandUsage(const char* program)
     << "  tar [cxt][vfz] file.tar file/dir1 file/dir2 ... - create a tar "
        "archive\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"
 #if defined(_WIN32) && !defined(__CYGWIN__)
     << "  write_regv key value      - write registry value\n"
     << "  delete_regv key           - delete registry value\n"
@@ -1096,6 +1098,34 @@ int cmake::ExecuteCMakeCommand(std::vector<std::string>& args)
         }
       return 0;
       }
+    // Touch file
+    else if (args[1] == "touch" && args.size() > 2)
+      {
+      for (std::string::size_type cc = 2; cc < args.size(); cc ++)
+        {
+        // Complain if the file could not be removed, still exists,
+        // and the -f option was not given.
+        if(!cmSystemTools::Touch(args[cc].c_str(), true))
+          {
+          return 1;
+          }
+        }
+      return 0;
+      }
+    // Touch file
+    else if (args[1] == "touch_nocreate" && args.size() > 2)
+      {
+      for (std::string::size_type cc = 2; cc < args.size(); cc ++)
+        {
+        // Complain if the file could not be removed, still exists,
+        // and the -f option was not given.
+        if(!cmSystemTools::Touch(args[cc].c_str(), false))
+          {
+          return 1;
+          }
+        }
+      return 0;
+      }
 
     // Clock command
     else if (args[1] == "time" && args.size() > 2)

Source/kwsys/SystemTools.cxx

@@ -50,6 +50,7 @@
 
 // support for realpath call
 #ifndef _WIN32
+#include <utime.h>
 #include <limits.h>
 #include <sys/param.h>
 #include <sys/wait.h>
@@ -75,6 +76,11 @@
 # define HAVE_TTY_INFO 1
 #endif
 
+#ifdef _MSC_VER
+#include <sys/utime.h>
+#else
+#include <utime.h>
+#endif
 
 // This is a hack to prevent warnings about these functions being
 // declared but not referenced.
@@ -836,6 +842,36 @@ bool SystemTools::FileExists(const char* filename)
     }
 }
 
+bool SystemTools::Touch(const char* filename, bool create)
+{
+  if(create && !SystemTools::FileExists(filename))
+    {
+    FILE* file = fopen(filename, "a+b");
+    if(file)
+      {
+      fclose(file);
+      return true;
+      }
+    return false;
+    }
+#ifdef _MSC_VER
+#define utime _utime
+#define utimbuf _utimbuf
+#endif
+  struct stat fromStat;
+  if(stat(filename, &fromStat) < 0)
+    {
+    return false;
+    }
+  struct utimbuf buf;
+  buf.actime = fromStat.st_atime;
+  buf.modtime = SystemTools::GetTime();
+  if(utime(filename, &buf) < 0)
+    {
+    return false;
+    }
+  return true;
+}
 
 bool SystemTools::FileTimeCompare(const char* f1, const char* f2,
                                   int* result)

Source/kwsys/SystemTools.hxx.in

@@ -279,6 +279,11 @@ public:
    */
   static unsigned long FileLength(const char *filename);
 
+  /**
+     Change the modification time or create a file
+  */
+  static bool Touch(const char* filename, bool create);
+  
   /**
    *  Compare file modification times.
    *  Return true for successful comparison and false for error.