add hw2

node_modules/d3-dsv/bin/dsv2dsv.js

@@ -0,0 +1,35 @@
+#!/usr/bin/env node
+
+import {EOL} from "os";
+import {basename, dirname, resolve} from "path";
+import {readFileSync} from "fs";
+import {fileURLToPath} from "url";
+import rw from "rw";
+import {program} from "commander";
+import iconv from "iconv-lite";
+import {dsvFormat} from "../src/index.js";
+
+const progname = basename(process.argv[1]);
+const defaultInDelimiter = progname.slice(0, 3) === "tsv" ? "\t" : ",";
+const defaultOutDelimiter = progname.slice(-3) === "tsv" ? "\t" : ",";
+
+const options = program
+    .version(JSON.parse(readFileSync(resolve(dirname(fileURLToPath(import.meta.url)), "../package.json"))).version)
+    .usage("[options] [file]")
+    .option("-o, --out <file>", "output file name; defaults to “-” for stdout", "-")
+    .option("-r, --input-delimiter <character>", "input delimiter character", defaultInDelimiter)
+    .option("-w, --output-delimiter <character>", "output delimiter character", defaultOutDelimiter)
+    .option("--input-encoding <encoding>", "input character encoding; defaults to “utf8”", "utf8")
+    .option("--output-encoding <encoding>", "output character encoding; defaults to “utf8”", "utf8")
+    .parse(process.argv)
+    .opts();
+
+const inFormat = dsvFormat(options.inputDelimiter);
+const outFormat = dsvFormat(options.outputDelimiter);
+
+rw.dash.readFile(program.args[0] || "-", (error, text) => {
+  if (error) throw error;
+  rw.dash.writeFile("-", iconv.encode(outFormat.format(inFormat.parse(iconv.decode(text, options.inputEncoding))) + EOL, options.outputEncoding), (error) => {
+    if (error) throw error;
+  });
+});