How to execute vimdiff command from inside a java program

Question

I have a list of files for which I have to run the vimdiff command and save the output as a html file.I am doing this with Java. Below is the command I am trying to execute

String cmd = "vimdiff -c 'set foldlevel=9999' src/test/resources/testdata/output/html_output_before_changes/file1.html src/test/resources/testdata/output/html_output_after_changes/file2.html -c TOhtml -c 'w! different.html' -c 'qa!'"

When I run the below code, the code is getting executed. But I am not able to see the file getting generated.

Runtime rt = Runtime.getRuntime();
Process process = rt.exec(cmd);

The command is running fine when executed from a terminal. But its not working when executed inside a java program. Can someone help me with this issue? I did a lot of search but not able to proceed with this.

Answer 1

You're using :TOhtml and write the result as different.html . If you're not sure where to locate the file, check the current working directory of the Java process, do a file search of your hard disk, or specify an absolute path in the Vim command to be sure.

You won't see anything from Vim's operation itself. Using process. getInputStream() , you could obtain what Vim wrote to the terminal during its operation, but that would just amount to a garble of characters, as Vim is using special ANSI escape sequences to control the terminal, position the cursor, etc.

To use Vim non-interactively, it is recommended to pass the following options:

-T dumb           Avoids errors in case the terminal detection goes wrong.
-n                No swapfile.
-i NONE           Ignore the |viminfo| file (to avoid disturbing the
                  user's settings).
-c 'set nomore'   Suppress the more-prompt when the screen is filled
                  with messages or output to avoid blocking.

Without a possibility to interact with Vim (from inside your Java program), a troubleshooting tip is enabling verbose logging: You can capture a full log of a Vim session with -V20vimlog . After quitting Vim, examine the vimlog log file for errors.

Answer 2

After Two days I found the below Solution:

I added the vimdiff command to a shell script and executed it using the following method and it worked like a gem.

Java method

try {
            File[] uiDiffDir = getFiles();

            for (File file : uiDiffDir) {

                String[] cmd = {"sh", shellScriptPath, file1, file2,
                        outputfile};
                Process p = Runtime.getRuntime().exec(cmd);
                p.waitFor();
                BufferedReader reader = new BufferedReader(new InputStreamReader(
                        p.getInputStream()));
                String line;
                while ((line = reader.readLine()) != null) {
                    System.out.println(line);
                }
            }
        } catch (IOException e) {
            e.printStackTrace();
        } catch (InterruptedException e) {
            e.printStackTrace();
        }

shell.sh

vimdiff -c 'set foldlevel=9999' $1 $2 -c TOhtml -c 'w! '"$3"'' -c 'qa!'

Note:

• file1 will be passed as a argument in the place of $1
• file2 will be passed as a argument in the place of $2
• outputfile will be passed as a argument in the place of $3