Debug a JSL for Dat File open and modify then save to close

[#1]

Anyone can help to fix the jsl below,

The goal is to open all dat file under the same directory and delete 2 rows, then save it.

Thanks

directory = Pick Directory();

fileNames = Files In Directory( directory );

For( iFile = 1, iFile <= N Items( fileNames ), iFile++, 

    filename = fileNames[iFile];

    If( Ends With( filename, ".dat" ), 

        dt = Open( directory || filename );

        //delete first 2 rows
        dt << Select Where( Row() < 3 );
        dt << delete rows;

        Close( dt, "save" );

    );
);

[#2 · Accepted solution]

Do you get any errors in the log?  If so, what are they?

I suspect the Select Where is running too soon, because the file is opening, which JMP will do in the background.  Try putting the line

dt << rerun formulas;

after the open() and see if that works.

What I usually do with code like this, is to run lines 1&2.  Find the first file that ends in .dat, and set your "filename' to its value, and then run one at a time, the open, select where, delete and close lines to see what happens.

[#3 · Accepted solution]

@Stokes,

Jim gave you some great debug suggestions. Below are a couple notes/potential issues. As Jim suggested, the errors in the LOG  or a description your task and what happens when you run the script would be informative.

• Instead of select where() and delete, you can use dt << delete rows(1::2);
• I often use wait( 0 ); after the save, to force its completion before continuing.
• Your script is looking for files with .DAT extension, which is a generic file type. You are reading it into JMP data table and then script a SAVE.  This has several potential issues,, unintended consequences:

1. The file type might need more details to be read properly, so the open might be causing an error. 
2. Assuming the file is read properly into a JMP data table, a SAVE will save the file as a .JMP file. Is that your intention? or do you want to save it as a .DAT file?  Often when users ask this type of question, they are wanting to use JMP to clean up a data file written by some automated metrology tool that has header information in a different format. That header information can cause Open() errors and other problems. So knowing the task will help the JMP community provide a solution. Depending upon the task, a Load Text File() or Open() with import text options might be required.
3. If the response to the Pick Directory() prompt is a directory that is readable but not writable, this could cause an error, or the file being saved in an unintended directory. For example if I modify your script to read .TXT files and pick the directory for JMP Samples/Import Data, the program will read the .txt files but save them as .JMP files, but not in the JMP Samples/Import Data directory because it is not writable. 

These items are intended to help clarify the type of details that are needed to help you.

[#4]

Thanks Jim, Morgon.

I used step by step method to check the loop, and it turns out the issue happens when open the .dat file.

There is no response after run open .dat.

I change it to open .txt and it works fine.

Do you have any idea why this happens and how to fix it?
Thanks

[#5]

I fixed the bug by doing modification below,

If( Right( y[i], 3 ) == "dat", ...............

Thanks a lot