Files and formats

Week nine, and Traversal’s attic is filling up: photographers testing course positions have shipped eleven thousand pictures, the nightly pipeline writes its logs, and the race director keeps asking, with rising warmth, about the export. All of it is files. All of it.

A fileConcept · lights on your mapfileA collection of bytes saved together under a name. Photos, songs, spreadsheets, and applications are all files; what differs is how their bytes are meant to be read. is bytes, saved together, given a name. That is the whole definition, and last scene is why it works: everything digital is bytes eventually, so a file is just bytes with a name and an address. The addresses live in folderConcept · lights on your mapfolderA container organising files and other folders into the tree every machine uses. Engineers say directory; the chain of folders to a file is its path.s, folders inside folders, the tree every machine on earth agreed on, and engineers will say directory where you say folder and mean nothing extra by it.

Reading the label

The name’s tail end, after the final dot, is the file extensionConcept · lights on your mapfile extensionThe part of a filename after the last dot: .jpg, .pdf, .csv. It helps the system pick an application to open the file. A label, not a spell: renaming it does not convert the bytes, only mislabels them., and it is a label, not a spell. Rename a photo to .pdf and you have converted nothing — you have lied about bytes, and some program will believe you at its peril.

Underneath the labels, one honest split. A text fileConcept · lights on your maptext fileA file whose bytes follow a text encoding, so any editor can open and read it. Code, configuration and logs are text; it stays human-readable without a special program. is bytes any editor can read as characters: the pipeline’s logs, every line of source in the codebase, the payload from Act I. A binary fileConcept · lights on your mapbinary fileA file whose bytes follow a structure needing the right program to interpret: photos, audio, most documents. Opened as text it shows gibberish, which is the tell. needs the right program to make sense at all: the eleven thousand JPEGs, the runner app itself. Open one as text and you get static. That gibberish is the tell, and now you know what it means.

The race director’s export, one row per finisher, will leave as .csv, a text file pretending to be a spreadsheet, exactly as promised in Act I’s sidebar. The photos will someday travel to finishers in bulk, and bulk travel is its own small science, which happens to be waiting at a tent in the mountains before this act is out.