added quickly cobbled together fetch script (node only, will port to python later)

utils/renamer/fetch.js

@@ -0,0 +1,74 @@
+let FS = require("fs")
+let Fetch = require("node-fetch")
+
+let config = {
+	query: `leib_(tas)`, // example query if no argument is passed
+
+	output: `./in/`, // directory to save your files
+	cache: `./cache.json`, // JSON file of cached tags, will speed up processing when used for the renamer script
+
+	limit: 10, // how many posts to pull in one go
+	rateLimit: 500, // time to wait between requests, in milliseconds, e621 imposes a rate limit of 2 requests per second
+}
+
+let cache;
+try {
+	cache = JSON.parse( FS.readFileSync(config.cache) )
+} catch ( e ) {
+	cache = {};
+}
+
+let args = process.argv;
+args.shift();
+args.shift();
+
+if ( args.length ) config.query = args.join(" ");
+
+let parse = async () => {
+	console.log(`Fetching: ${config.query}`)
+
+	let posts = [];
+	let last = '';
+
+	do {
+		let query = [`tags=${config.query}`]
+		if ( config.limit ) query.push(`limit=${config.limit}`)
+		if ( last ) query.push(`page=b${last}`)
+
+		query = encodeURI(query.join("&"));
+		console.log(`Querying: ${query}`)
+		let r = await Fetch( `https://e621.net/posts.json?${query}`, {
+			headers: {
+				'user-agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/87.0.4280.88 Safari/537.36'
+			}
+		} );
+		let j = JSON.parse(await r.text());	
+		posts = j.posts;
+	
+		for ( let i in posts ) {
+			let post = posts[i];
+			last = `${post.id}`
+			cache[post.file.md5] = post;
+
+			if ( FS.existsSync(`${config.output}${post.file.md5}.${post.file.ext}`) ) continue;
+
+			await Fetch(post.file.url).then(res => new Promise((resolve, reject) => {
+				const dest = FS.createWriteStream(`${config.output}${post.file.md5}.${post.file.ext}`);
+				res.body.pipe(dest);
+				dest.on('close', () => {
+					console.log(`Downloaded https://e621.net/posts/${post.id}`)
+					resolve()
+				});
+				dest.on('error', reject);
+			}));
+		}		
+
+		if ( config.rateLimit ) await new Promise( (resolve) => {
+			setTimeout(resolve, config.rateLimit)
+		} )
+	} while ( posts.length );
+
+	FS.writeFileSync(config.cache, JSON.stringify( cache, null, "\t" ))
+}
+
+parse();