ENH: apply patch from Mathieu, add argument -E md5sum to compute md5sums of

files, compatible to md5sum output

Alex

Source/cmSystemTools.cxx

@@ -22,6 +22,7 @@
 #include <cmsys/RegularExpression.hxx>
 #include <cmsys/Directory.hxx>
 #include <cmsys/System.h>
+#include <cmsys/MD5.h>
 
 // support for realpath call
 #ifndef _WIN32
@@ -1046,6 +1047,52 @@ bool cmSystemTools::CopyFileIfDifferent(const char* source,
   return Superclass::CopyFileIfDifferent(source, destination);
 }
 
+bool cmSystemTools::ComputeFileMD5(const char* source, char* md5out)
+{
+  if(!cmSystemTools::FileExists(source))
+    {
+    return false;
+    }
+
+  // Open files
+#if defined(_WIN32) || defined(__CYGWIN__)
+  cmsys_ios::ifstream fin(source, cmsys_ios::ios::binary | cmsys_ios::ios::in);
+#else
+  cmsys_ios::ifstream fin(source);
+#endif
+  if(!fin)
+    {
+    return false;
+    }
+
+  cmsysMD5* md5 = cmsysMD5_New();
+  cmsysMD5_Initialize(md5);
+
+  // Should be efficient enough on most system:
+  const int bufferSize = 4096;
+  char buffer[bufferSize];
+  // This copy loop is very sensitive on certain platforms with
+  // slightly broken stream libraries (like HPUX).  Normally, it is
+  // incorrect to not check the error condition on the fin.read()
+  // before using the data, but the fin.gcount() will be zero if an
+  // error occurred.  Therefore, the loop should be safe everywhere.
+  while(fin)
+    {
+    fin.read(buffer, bufferSize);
+    if(fin.gcount())
+      {
+      cmsysMD5_Append(md5, reinterpret_cast<unsigned char const*>(buffer), 
+                      fin.gcount());
+      }
+    }
+  cmsysMD5_FinalizeHex(md5, md5out);
+  cmsysMD5_Delete(md5);
+
+  fin.close();
+
+  return true;
+}
+
 void cmSystemTools::Glob(const char *directory, const char *regexp,
                          std::vector<std::string>& files)
 {

Source/cmSystemTools.h

@@ -165,6 +165,9 @@ public:
   static bool CopyFileIfDifferent(const char* source, 
     const char* destination);
 
+  ///! Compute the md5sum of a file
+  static bool ComputeFileMD5(const char* source, char* md5out);
+
   /**
    * Run an executable command and put the stdout in output.
    * A temporary file is created in the binaryDir for storing the

Source/cmake.cxx

@@ -865,6 +865,7 @@ void CMakeCommandUsage(const char* program)
     " line\n"
     << "  environment             - display the current enviroment\n"
     << "  make_directory dir      - create a directory\n"
+    << "  md5sum file1 [...]      - compute md5sum of files\n"
     << "  remove_directory dir    - remove a directory and its contents\n"
     << "  remove file1 file2 ...  - remove the file(s)\n"
     << "  tar [cxt][vfz] file.tar file/dir1 file/dir2 ... - create a tar.\n"
@@ -1056,6 +1057,31 @@ int cmake::ExecuteCMakeCommand(std::vector<std::string>& args)
       return 0;
     }
 
+    // Command to calculate the md5sum of a file
+    else if (args[1] == "md5sum" && args.size() >= 3)
+      {
+      char md5out[32];
+      for (std::string::size_type cc = 2; cc < args.size(); cc ++)
+        {
+        const char *filename = args[cc].c_str();
+        // Cannot compute md5sum of a directory
+        if(cmSystemTools::FileIsDirectory(filename))
+          {
+          std::cerr << "Error: " << filename << " is a directory" << std::endl;
+          }
+        else if(!cmSystemTools::ComputeFileMD5(filename, md5out))
+          {
+          // To mimic md5sum behavior in a shell:
+          std::cerr << filename << ": No such file or directory" << std::endl;
+          }
+        else
+          {
+          std::cout << std::string(md5out,32) << "  " << filename << std::endl;
+          }
+        }
+      return 1;
+      }
+
     // Command to change directory and run a program.
     else if (args[1] == "chdir" && args.size() >= 4)
       {