Hi,

I'm writing a program that reads a text file and launch my work URLs in it.
It worked fine, and very happy.

Then I added another foreach loop to count total number of lines.
After this, the main foreach won't work.

Does anyone know as to why this happens?
I might have missed something very obvious.

Thank you.

Regards,
ikel

module openurls;

import std.stdio : writeln, File, KeepTerminator;
import std.file;
import std.range;
import std.ascii;
import std.getopt : getopt, GetoptResult, defaultGetoptPrinter;
import std.process : browse;
import core.thread.osthread;
import core.time;


void main(string[] args)
{
    string input_filename = "";

    // Get command line option
    GetoptResult user_args = getopt(args,
        "input|i", "A list of URLs separated by new lines.", &input_filename);

    // Does user need help?
    if (user_args.helpWanted)
    {
        defaultGetoptPrinter("Command line options for Open URLs.",
            user_args.options);
    }

    // Is input file specified?
    if (input_filename.length == 0)
    {
        writeln("Open URL: No file specified.\n");
        defaultGetoptPrinter("Command line option for Open URLs.",
            user_args.options);
        return;
    }

    // Does the file exist?
    if (!input_filename.exists)
    {
        writeln("Open URL: input file --" ~ input_filename ~ "-- does not exist.\n");
        return;
    }
    else
    {
        writeln("Open URL: reading --" ~ input_filename ~ "--");
    }

    // Open input file for reading
    size_t line_count = 0;
    File input_file = File(input_filename);
    auto file_range = input_file.byLine(KeepTerminator.no, std.ascii.newline);

    // if this foreach not commented out
    // the last foreach won't run.
    foreach (char[] line; file_range)
    {
        line_count += 1;
    }

    // the MAIN foreach loop
    // -- won't run if above foreach is enabled
    foreach (char[] line; file_range)
    {
        if (!line.empty)
        {
            writeln("Open URL: " ~ line);
            Thread.sleep(dur!("seconds")(2));
            browse(line);
        }
    }

    writeln("Open URL: completed");

    writeln("Closing " ~ input_filename);
    input_file.close();
}

On 8/7/22 10:11 PM, ikelaiah wrote:

...

Here you open the file

And then wrap it in a byline range.

For this foreach loop, you read every line in the file, exhausting the file (the input stream for the file is empty).

And now, you tried to read it again! Which means you are trying to read more data from an empty stream.

You need to either a) reopen the file, or b) do both in the same loop.

-Steve

On Monday, 8 August 2022 at 02:45:54 UTC, Steven Schveighoffer wrote:

Steve! You are Legend!
Thank you.
It is obvious now the second foreach is reading from an empty stream!

Regards,
ikel