Opening Files#

In this section we will start building our actual script piece-by-piece. The script we are currently working on in any section will always appear like this:

//our script will be here!

Let's start by putting in our loop functionality from the previous section:

folder = "path/to/file"
file_list = getFileList(folder);
number_of_files = file_list.length;

for (i=0; i<number_of_files; i++) {
    // nothing yet
}

Now that we have learned how to loop through files, we will open them. How can we find out how to open files? There are always two answers:

• Go to the ImageJ macro guide
• Use the macro recorder

In this case we can see using the macro recorder that the function to open a file is:

open("path/to/file");

What should we put for "path/to/file"? This is the path of a file, which is like an address to where the file lives on the computer. In this case we know the path of our files is path/to/file. We need to pass in as an argument to the open function a concatenation of this path (a string) and the file name (another string).

folder = "path/to/file";
file_list = getFileList(folder);
number_of_files = file_list.length;

file_path = folder + File.separator + file_list[0];
print(file_path);

Play around with this script a bit. See what happens when you change various things. Make sure you understand, in the final file_path variable, where each of the components come from.

Now, add this code snippet to your script, but instead of using print to print the path of the file, use open to open the file.

folder = "path/to/file";
file_list = getFileList(folder);
number_of_files = file_list.length;

for (i=0; i<number_of_files; i++) {
    file_path = folder + File.separator + file_list[i];
    open(file_path);
}

If you run the code in the second cell, you will see that all files will open!