shp2json

#!/usr/bin/env node

var fs = require("fs"),
    commander = require("commander"),
    shapefile = require("../");

commander
    .version(require("../package.json").version)
    .usage("[options] [file]")
    .description("Convert a Shapefile to GeoJSON.")
    .option("-o, --out <file>", "output file name; defaults to “-” for stdout", "-")
    .option("-n, --newline-delimited", "output newline-delimited JSON")
    .option("-g, --geometry", "output geometries (implies --ignore-properties)")
    .option("--ignore-properties", "don’t read shapefile properties (.dbf)")
    .option("--encoding <encoding>", "character encoding for shapefile properties (.dbf)")
    .option("--crs-name <name>", "specify a named CRS for the output feature collection")
    .parse(process.argv);

if (commander.args.length === 0) commander.args[0] = "-";
else if (commander.args.length !== 1) {
  console.error();
  console.error("  error: multiple input files");
  console.error();
  process.exit(1);
}

var out = (commander.out === "-" ? process.stdout : fs.createWriteStream(commander.out)).on("error", handleEpipe);

shapefile.open(
    commander.args[0] === "-" ? process.stdin : commander.args[0],
    commander.geometry || commander.ignoreProperties ? null : undefined,
    {encoding: commander.encoding})
  .then(commander.newlineDelimited
      ? (commander.geometry ? writeNewlineDelimitedGeometries : writeNewlineDelimitedFeatures)
      : (commander.geometry ? writeGeometryCollection : writeFeatureCollection))
  .catch(handleError);

function writeNewlineDelimitedGeometries(source) {
  return source.read().then(function repeat(result) {
    if (result.done) return;
    out.write(JSON.stringify(result.value.geometry));
    out.write("\n");
    return source.read().then(repeat);
  }).then(function() {
    if (out !== process.stdout) out.end();
  });
}

function writeNewlineDelimitedFeatures(source) {
  return source.read().then(function repeat(result) {
    if (result.done) return;
    out.write(JSON.stringify(result.value));
    out.write("\n");
    return source.read().then(repeat);
  }).then(function() {
    if (out !== process.stdout) out.end();
  });
}

function writeGeometryCollection(source) {
  out.write("{\"type\":\"GeometryCollection\",\"bbox\":");
  out.write(JSON.stringify(source.bbox));
  out.write(",\"geometries\":[");
  return source.read().then(function(result) {
    if (result.done) return;
    out.write(JSON.stringify(result.value.geometry));
    return source.read().then(function repeat(result) {
      if (result.done) return;
      out.write(",");
      out.write(JSON.stringify(result.value.geometry));
      return source.read().then(repeat);
    });
  }).then(function() {
    out[out === process.stdout ? "write" : "end"]("]}\n");
  });
}

function writeFeatureCollection(source) {
  out.write("{\"type\":\"FeatureCollection\",\"bbox\":");
  out.write(JSON.stringify(source.bbox));
  if (commander.crsName) {
    out.write(",\"crs\":{\"type\":\"name\",\"properties\":{\"name\":");
    out.write(JSON.stringify(commander.crsName + ""));
    out.write("}}");
  }
  out.write(",\"features\":[");
  return source.read().then(function(result) {
    if (result.done) return;
    out.write(JSON.stringify(result.value));
    return source.read().then(function repeat(result) {
      if (result.done) return;
      out.write(",");
      out.write(JSON.stringify(result.value));
      return source.read().then(repeat);
    });
  }).then(function() {
    out[out === process.stdout ? "write" : "end"]("]}\n");
  });
}

function handleEpipe(error) {
  if (error.code === "EPIPE" || error.errno === "EPIPE") {
    process.exit(0);
  }
}

function handleError(error) {
  console.error();
  console.error("  error: " + error.message);
  console.error();
  process.exit(1);
}