Copying fifos hangs.

README.md

@@ -191,7 +191,9 @@ cp('-Rf', '/tmp/*', '/usr/local/*', '/home/tmp');
 cp('-Rf', ['/tmp/*', '/usr/local/*'], '/home/tmp'); // same as above
 ```
 
-Copies files.
+Copies files. Natively, this command will skip special unix files like
+fifos. To add support for special unix cases
+[see this issue](https://github.com/shelljs/shelljs/issues/748) (WIP).
 
 
 ### pushd([options,] [dir | '-N' | '+N'])

src/cp.js

@@ -34,16 +34,30 @@ function copyFileSync(srcFile, destFile, options) {
     // If we're here, destFile probably doesn't exist, so just do a normal copy
   }
 
-  if (fs.lstatSync(srcFile).isSymbolicLink() && !options.followsymlink) {
-    try {
-      fs.lstatSync(destFile);
-      common.unlinkSync(destFile); // re-link it
-    } catch (e) {
-      // it doesn't exist, so no work needs to be done
-    }
+  var srcFileStat = fs.lstatSync(srcFile);
 
-    var symlinkFull = fs.readlinkSync(srcFile);
-    fs.symlinkSync(symlinkFull, destFile, isWindows ? 'junction' : null);
+  if (srcFileStat.isSymbolicLink()) {
+    if (options.followsymlink) {
+      // recurse to copy the target of the symlink to the dest to ensure we handle complex scenarios
+      return copyFileSync(fs.realpathSync(srcFile), destFile, options);
+    } else {
+      try {
+        fs.lstatSync(destFile);
+        common.unlinkSync(destFile); // re-link it
+      } catch (e) {
+        // it doesn't exist, so no work needs to be done
+      }
+
+      var symlinkFull = fs.readlinkSync(srcFile);
+      fs.symlinkSync(symlinkFull, destFile, isWindows ? 'junction' : null);
+    }
+  // skip unix-like files. Anticipate adding support via a plugin.
+  } else if (srcFileStat.isFIFO() || srcFileStat.isCharacterDevice() || srcFileStat.isBlockDevice()) {
+    var type = 'unknown file';
+    if (srcFileStat.isFIFO()) type = 'fifo';
+    if (srcFileStat.isCharacterDevice()) type = 'block device';
+    if (srcFileStat.isBlockDevice()) type = 'character device';
+    common.error('copyFileSync: ' + type + ' is not supported (' + srcFile + ')', { continue: true });
   } else {
     var buf = common.buffer();
     var bufLength = buf.length;
@@ -67,7 +81,7 @@ function copyFileSync(srcFile, destFile, options) {
     }
 
     while (bytesRead === bufLength) {
-      bytesRead = fs.readSync(fdr, buf, 0, bufLength, pos);
+      bytesRead = fs.readSync(fdr, buf, 0, bufLength, pos || -1);
       fs.writeSync(fdw, buf, 0, bytesRead);
       pos += bytesRead;
     }
@@ -204,7 +218,9 @@ function cpcheckcycle(sourceDir, srcFile) {
 //@ cp('-Rf', ['/tmp/*', '/usr/local/*'], '/home/tmp'); // same as above
 //@ ```
 //@
-//@ Copies files.
+//@ Copies files. Natively, this command will skip special unix files like
+//@ fifos. To add support for special unix cases
+//@ [see this issue](https://github.com/shelljs/shelljs/issues/748) (WIP).
 function _cp(options, sources, dest) {
   // If we're missing -R, it actually implies -L (unless -P is explicit)
   if (options.followsymlink) {

test/cp.js

@@ -7,6 +7,7 @@ import utils from './utils/utils';
 
 const oldMaxDepth = shell.config.maxdepth;
 const CWD = process.cwd();
+const isRoot = process.getuid && process.getuid() === 0;
 
 test.beforeEach(t => {
   t.context.tmp = utils.getTempDir();
@@ -755,3 +756,52 @@ test('should not overwrite recently created files (not give error no-force mode)
   // Ensure First file is copied
   t.is(shell.cat(`${t.context.tmp}/file1`).toString(), 'test1');
 });
+
+test('should warn about fifos', t => {
+  if (process.platform !== 'win32') { // fs.exists doesn't support fifos on windows
+    shell.exec(`mkfifo ${t.context.tmp}/fifo`);
+    shell.exec(`printf test1 > ${t.context.tmp}/fifo`, { async: true });
+    t.truthy(fs.existsSync(`${t.context.tmp}/fifo`));
+    const result = shell.cp(`${t.context.tmp}/fifo`, `${t.context.tmp}/newFifo`);
+    t.truthy(shell.error());
+    t.is(result.code, 1);
+    t.falsy(fs.existsSync(`${t.context.tmp}/newFifo`));
+  }
+});
+
+test('should warn about fifos via symlinks', t => {
+  if (process.platform !== 'win32') { // fs.exists doesn't support fifos on windows
+    shell.exec(`mkfifo ${t.context.tmp}/fifo`);
+    shell.exec(`printf test1 > ${t.context.tmp}/fifo`, { async: true });
+    shell.pushd(t.context.tmp);
+    fs.symlinkSync('fifo', 'symFifo');
+    shell.popd();
+    t.truthy(fs.existsSync(`${t.context.tmp}/symFifo`));
+    const result = shell.cp(`${t.context.tmp}/symFifo`, `${t.context.tmp}/newFifo`);
+    t.truthy(shell.error());
+    t.is(result.code, 1);
+    t.falsy(fs.existsSync(`${t.context.tmp}/newFifo`));
+  }
+});
+
+test('should warn about character devices', t => {
+  if (process.platform !== 'win32' && isRoot) {
+    shell.exec(`mknod ${t.context.tmp}/zero c 1 5`);
+    t.truthy(fs.existsSync(`${t.context.tmp}/zero`));
+    const result = shell.cp(`${t.context.tmp}/zero`, `${t.context.tmp}/newZero`);
+    t.truthy(shell.error());
+    t.is(result.code, 1);
+    t.falsy(fs.existsSync(`${t.context.tmp}/newZero`));
+  }
+});
+
+test('should warn about block devices', t => {
+  if (process.platform !== 'win32' && isRoot) {
+    shell.exec(`mknod ${t.context.tmp}/sda1 b 8 1`);
+    t.truthy(fs.existsSync(`${t.context.tmp}/sda1`));
+    const result = shell.cp(`${t.context.tmp}/sda1`, `${t.context.tmp}/newSda1`);
+    t.truthy(shell.error());
+    t.is(result.code, 1);
+    t.falsy(fs.existsSync(`${t.context.tmp}/newSda1`));
+  }
+});