Delphi writeln text file

Next Step is to state, what we intend to do with the file. Everything is taken care of now — so we can proceed to read the file. We will one line at a time, using the ReadLn procedure which takes two parameters. Once we finish Reading our File, we need to close it.

This can be done with the CloseFile Procedure:. Below is a simple program that reads a textfile called provinces. When the last line is read, the loops exist. We also declare a string variable, which will contain what we want to write into the text file.

I have made an console application A which runs independently every day to download files and uses WriteLn 'text' to display progress in the console.

I need A to write a log to a text file as well as display it's progress, so I have two questions:. Is there a way for my GUI application B to display the output from A in realtime from the text file, or at least know when A is complete. At present I display a message "Please wait for external import to complete and press OK" after which it refreshes the tables. You should be able to redirect the output from A to B and then display it in B and log it in B.

Its been a long times since I used Delphi but if B is a. Stack Overflow for Teams — Collaborate and share knowledge with a private group. Create a free Team What is Teams? Collectives on Stack Overflow. Note that the last end keyword is always followed by a dot character -- also called point, period , or final stop. As you've probably guessed ; this indicates the end of the project file.

Communication with the user is handled with Read and Write commands: WriteLn displays a message, followed by an end-of-line code that positions the text cursor at the beginning of the next line. Thus, the ouput of the next Write command will appear directly after the displayed text.

The Read command waits until the number of data values that are typed separated by spaces, if there is more than 1 value is equal to the number of variables provided. We ask Delphi to assign a file handle for a file called 'Test. Next, we must open the file using this handle. This operation tells Delphi how we want to treat the file. There are 3 ways of opening the file:. ReWrite Opens a file as new - discards existing contents if file exists Reset Opens a file for read and write access Append Opens a file for appending to the end such as a log file.

We'll cover the access mechanisms for text and binary files separately. Meanwhile, when we have finished, we must close the file:. CloseFile myFile ;. Text files are great for simple uses, such as where we record a processing log. Text files fall short when reading and writing structured data.

They do support number to string and string to number formatting, but you are often better off defining your own record structure and using a typed binary file instead. The ShowMessage routine displays the following : Hello World. If we replaced the ReWrite routine with Append , and rerun the code, the existing file would then contain:.

Hello World Hello World. Notice that we have used WriteLn and ReadLn to write to and read from the file. This writes the given text plus a carriage return and line feed to the text.