In a 2014 Linux Rain article I describe a fast 'points plotter' for Google Earth. First I copy a list of latitude/longitudes (lat/lons) from a spreadsheet to the clipboard, then I launch a shell script with a keyboard shortcut. The script builds a KML file from the copied list and opens the KML for…

In this article I explain one way to group data items with AWK arrays. The code is a little mysterious but the results are impressive, especially in my second example! Case 1: Cricket stats The table 'runs' is tab-separated and lists the 86 national team cricket players who scored (or have so far…

There are two easy-to-use tools for generating numerical sequences. 'Brace expansion' is a BASH shell built-in, while the seq command is included in the GNU/Linux 'coreutils' package. Each tool has its peculiarities and advantages, as shown below. Simple sequences One difference between the two…

I often look something up in Wikipedia when reading non-browser documents, like PDFs, ODTs and emails. I wanted to have a little desktop window for those look-ups - somewhere I could check Wikipedia without opening a browser and without leaving the document I'm reading. This article describes how I…

I have a data-entry script which adds records to a plain-text data table. It's a fairly complicated script with a GUI dialog, and until recently it added one record at a time. To add another record, I had to launch the script again. Was there a simple way (I asked myself) to re-run the script, or…

Nothing gives my wife the Screaming Meemies like dates in spreadsheets. Unless she formats the target cell in advance as text, the spreadsheet will turn a perfectly innocent, non-date string like 23/2/6 into '23-Feb-2006'. When she types 6420-11-3, according to both LibreOffice Calc and Gnumeric,…

In a plain-text table, the first or header line usually contains the names of the fields. In this article I've pulled together a variety of ways to add and delete a header, and also how to do things with the rest of the table while leaving the header intact as the first line in the file. Add a…

This article compares 3 different ways to join tables on a common field. All 3 work OK on small tables, but there's a big difference in speed when the tables to be joined are large, as shown below. Table joining isn't something you need to do if you store data in a simple, flat-file database like a…

In a previous Linux Rain article I compared different ways to delete blank lines, and showed that the AWK way was the simplest and most thorough. Here I show how to split a text file into multiple text files using a surprisingly simple AWK command. Background In 2013 I published an article in Free…

In a previous Linux Rain article I explained how to use the YAD dialog to do multiple-item data entry in a GUI. Here I show one way to allow users to check and edit what they've entered in YAD. I also explain how to offer default, editable inputs in terminal-based data entry, and how to color the…