diff options
Diffstat (limited to 'infrastructure/framework-src/modules/process.js')
-rw-r--r-- | infrastructure/framework-src/modules/process.js | 91 |
1 files changed, 91 insertions, 0 deletions
diff --git a/infrastructure/framework-src/modules/process.js b/infrastructure/framework-src/modules/process.js new file mode 100644 index 0000000..48ab62e --- /dev/null +++ b/infrastructure/framework-src/modules/process.js @@ -0,0 +1,91 @@ +/** + * Simple way to execute external commands through javascript + * + * @example + cmd = exec("cat"); + System.out.println("First: " +cmd.write("this is a loop.").read(Process.READ_AVAILABLE)); // prints "this is a loop." + System.out.println("Second: " +cmd.writeAndClose(" hi there").result()); // prints "this is a loop. hi there" + * + */ + +jimport("java.lang.Runtime"); +jimport("java.io.BufferedInputStream"); +jimport("java.io.BufferedOutputStream"); +jimport("java.lang.System"); + +/* returns a process */ +function exec(process) { + return new Process(process); +}; + +function Process(cmd) { + this.cmd = cmd; + this.proc = Runtime.getRuntime().exec(cmd); + this.resultText = ""; + this.inputStream = new BufferedInputStream(this.proc.getInputStream()); + this.errorStream = new BufferedInputStream(this.proc.getErrorStream()); + this.outputStream = new BufferedOutputStream(this.proc.getOutputStream()); +} + +Process.CHUNK_SIZE = 1024; +Process.READ_ALL = -1; +Process.READ_AVAILABLE = -2; + +Process.prototype.write = function(stdinText) { + this.outputStream.write(new java.lang.String(stdinText).getBytes()); + this.outputStream.flush(); + return this; +}; + +Process.prototype.writeAndClose = function(stdinText) { + this.write(stdinText); + this.outputStream.close(); + return this; +}; + +/* Python file-like behavior: read specified number of bytes, else until EOF*/ +Process.prototype.read = function(nbytesToRead, stream) { + var inputStream = stream || this.inputStream; + var availBytes = inputStream.available(); + if (!availBytes) return null; + + var result = ""; + var nbytes = nbytesToRead || Process.READ_ALL; + var readAll = (nbytes == Process.READ_ALL); + var readAvailable = (nbytes == Process.READ_AVAILABLE); + while (nbytes > 0 || readAll || readAvailable) { + var chunkSize = readAll ? Process.CHUNK_SIZE : + readAvailable ? Process.CHUNK_SIZE : nbytes; + + // allocate a java byte array + var bytes = java.lang.reflect.Array.newInstance(java.lang.Byte.TYPE, chunkSize); + + var len = inputStream.read(bytes, 0, chunkSize); + + // at end of stream, or when we run out of data, stop reading in chunks. + if (len == -1) break; + if (nbytes > 0) nbytes -= len; + + result += new java.lang.String(bytes); + + if (readAvailable && inputStream.available() == 0) break; + } + + this.resultText += new String(result); + return new String(result); +}; + +Process.prototype.result = function() { + this.outputStream.close(); + this.proc.waitFor(); + this.read(Process.READ_ALL, this.inputStream); + return new String(this.resultText); +}; + +Process.prototype.resultOrError = function() { + this.proc.waitFor(); + this.read(Process.READ_ALL, this.inputStream); + var result = this.resultText; + if(!result || result == "") result = this.read(Process.READ_ALL, this.errorStream); + return result || ""; +}; |