add example/unzip.js

Author: thejoshwolfe

test/dump.js renamed to examples/dump.js

@@ -0,0 +1,99 @@
+
+var yauzl = require("../");
+var path = require("path");
+var fs = require("fs");
+var Transform = require("stream").Transform;
+var Pend = require("pend"); // npm install pend
+
+var zipFilePath = process.argv[2];
+if (zipFilePath == null || /^-/.test(zipFilePath)) {
+  console.log(
+    "usage: node unzip.js path/to/file.zip\n" +
+    "\n" +
+    "unzips the specified zip file into the current directory");
+  process.exit(1);
+}
+
+function mkdirpSync(dir) {
+  if (dir === ".") return;
+  try {
+    fs.statSync(dir);
+    return; // already exists
+  } catch (e) {
+  }
+  var parent = path.dirname(dir);
+  mkdirpSync(parent);
+
+  process.stdout.write(dir.replace(/\/$/, "") + "/\n");
+  fs.mkdirSync(dir);
+}
+
+yauzl.open(zipFilePath, function(err, zipfile) {
+  if (err) throw err;
+
+  // Use Pend to do one thing at a time.
+  // This enables prettier progress output.
+  var pend = new Pend();
+  pend.max = 1;
+
+  // don't start any of the other `go()`s until we're done creating directories
+  pend.go(function(callback) {
+    zipfile.on("end", function() {
+      callback();
+    });
+  });
+
+  zipfile.on("entry", function(entry) {
+    if (/\/$/.test(entry.fileName)) {
+      // directory file names end with '/'
+      mkdirpSync(entry.fileName);
+    } else {
+      // ensure parent directory exists
+      mkdirpSync(path.dirname(entry.fileName));
+      // call openReadStream before we return from this function,
+      // or else the zipfile might autoclose before we get a chance to read it.
+      zipfile.openReadStream(entry, function(err, readStream) {
+        if (err) throw err;
+        pend.go(function(callback) {
+          // report progress through large files
+          var byteCount = 0;
+          var totalBytes = entry.uncompressedSize;
+          var lastReportedString = byteCount + "/" + totalBytes + "  0%";
+          process.stdout.write(entry.fileName + "..." + lastReportedString);
+          function reportString(msg) {
+            var clearString = "";
+            for (var i = 0; i < lastReportedString.length; i++) {
+              clearString += "\b";
+              if (i >= msg.length) {
+                clearString += " \b";
+              }
+            }
+            process.stdout.write(clearString + msg);
+            lastReportedString = msg;
+          }
+          // report progress at 60Hz
+          var progressInterval = setInterval(function() {
+            reportString(byteCount + "/" + totalBytes + "  " + ((byteCount / totalBytes * 100) | 0) + "%");
+          }, 1000 / 60);
+          var filter = new Transform();
+          filter._transform = function(chunk, encoding, cb) {
+            byteCount += chunk.length;
+            cb(null, chunk);
+          };
+          filter._flush = function(cb) {
+            clearInterval(progressInterval);
+            reportString("");
+            // delete the "..."
+            process.stdout.write("\b \b\b \b\b \b\n");
+            cb();
+            callback();
+          };
+
+          // pump file contents
+          readStream.pipe(filter).pipe(fs.createWriteStream(entry.fileName));
+        });
+      });
+    }
+  });
+});
+