tag/command-line

When you use a word processor, formatting text so the lines will fit in the available space on the target device should not be an issue. But when working at the terminal, things are not that easy. Of course, you can always break lines by hand using your favorite text editor, but this is rarely desirable, and it’s even out of the question for automated processing. Hopefully, the POSIX fold utility and the GNU/BSD fmt command can help you to reflow a text so lines will not exceed a given length.

In a previous video, we talked about the cut command which can be used to extract columns from a CSV or tabular text data file.

The cut command is a POSIX-defined utility to remove unwanted data from a tabular text data file. With the cut utility you can remove bytes, character range ("columns") or fields on each line of an input file. Something that is particularly useful when you have to pre-process a CSV file from (or "for") a spreadsheet or a database.

You probably know I’m a Bash and shell scripting fan. But I really like databases too. And as such, I couldn’t have missed the join command to merge two text data files!

Awk is a powerful tool using pattern matching to identify the data to process in a file. But Awk patterns are much more versatile than their sed counterpart.