Posts by category (most recent post first):

Data auditing, cleaning and processing

Find the first, last, nth and first+last occurrence of a string (2024-06-21)
     Showing the easiest ways I know to do these jobs

Extract successive pairs from a list, and rapidly grow a list (2024-05-03)
     How to do it, but be careful with the "yes" command

Post- and pre-incrementing (var++ and ++var) with AWK (2024-04-26)
     Pre or post? Sometimes it doesn't matter

Finding near-duplicate spelling variants (2024-04-05)
     How to search for ä/ae-type duplicates

Table in a PDF to a TSV, on the command line (2024-03-29)
     Use the pdftotext utility and clean up with sed and AWK

Finding identifier codes with and without extra characters (2024-02-02)
     A command-line solution for finding near-duplicate values

Characters and encoding

Mojibake, anyone? (2024-07-19)
     More delightful examples from real-world data audits

How to detect and convert those baffling ruffians (2024-06-28)
     Beware of Latin ligatures

A text full of nulls - what happened? (2024-06-07)
     Hint: Microsoft Windows encoding

Print a character as a variable with BASH printf (2024-03-22)
     There's a right way and a wrong way, but both work

Counterfeit spaces: the NBSP menace (2024-03-01)
     How to visualise and replace (or delete) NBSPs

Mojibake with 2 hearts and 52 bytes (2024-02-09)
     Encoding ping-pong between UTF-8 and Windows-1252

Data formatting

Line spacing tricks (2024-07-12)
     sed, AWK and grep are your friends

Archiving images: TIFF vs PPM (2024-07-04)
     Which format will be more easily readable in 1000 years?

DataMatrix codes and data content (2024-04-19)
     Squeezing lots of information into a tiny graphic

CSV to JSON to CSV, awkwardly (2024-04-12)
     Recovering CSV data from an awful JSON file

Convert Microsoft serial day numbers to YYYY-MM-DD (2024-02-23)
     Easy, if you remember that 1900-02-29 didn't happen

Data analysis examples

Minimum, maximum and range by group (2024-05-24)
     GNU datamash is great, but sometimes more is needed

Data entry and display

⇝ Middle-click paste a series of numbers or letters (2024-07-26) ⇜ LATEST
     A neat trick that might be handy someday

Mapping with gnuplot, part 5 (2024-03-15)
     Building a dialog for choosing data to be mapped

Mapping with gnuplot, part 4 (2024-03-08)
     Showing a much-improved way to build a basemap

Useful programs for command-line data ops

Five useful tweaks for the ranger file manager (2024-06-14)
     Easy ways to make this CLI utility even better

Polyglot and round-trip translations (2024-05-31)
     Flexible translations with translate-shell

GNU datamash and months (2024-02-16)
     How to help datamash over the month-sorting hurdle

AWK tips and tricks

AWK one-liners to multi-liners (2024-05-10)
     A little-known "pretty print" option

Miscellaneous stuff

The curious world of UUIDs (2024-05-17)
     What they are and how to tinker with them