Executing System Commands In Java

Question

Hi,
     I am not sure if this is a bug � or I am just doing this wrong. I have
written a program to move files into ~/.trash/ . My problem is that this
works only for files without spaces � but for files with spaces it will
not work. Some of my code is below.
I have temporarily uploaded the complete file at
http://www.geocities.com/carmaski/Remove.java
public static void main(String args[]) {
String currDir = System.getProperty("user.dir") + "/";
String trashDir = "\" \"/home/masca/.trash/";
String commandString = "";
for (int i = 0; i < args.length; i++ ) {
File tmpFile = new File(currDir + args);
if(tmpFile.exists()) {
commandString = "mv \"" + currDir + args[i] + trashDir
+ args[i] + getTimeTag() + "\"";
System.out.println("The command would be -- " +
commandString);
try {
Process p = Runtime.getRuntime().exec(commandString);
catch (IOException e) {
e.printStackTrace();
System.exit(-1);
As an example I tried � this with a file that has a space � and I get
the following output.
The command would be -- mv "/home/masca/WORK/Text File"
"/home/masca/.trash/Text File_2005.04.17_04hrs:25mins:36secs"
However the file remains without being moved.
I cannot understand why the mv command does not work in java. If I
manually copy this to the command line I can get the file to work. It
should be noted that this program works perfectly if the file does not
have a space.
Regards,
Rio

Answer 1

Use File.separator or simply / instead of Windows
backslashes.
- SaishI think OP is on a unix machine, and he still needs to escape the spaces. The escape character is, of course, a back-slash.
Depending on the shell (my experience is with bash), to execute the command mv Test File.txt newTest File.txt, the file names either need to be double-quoted so that the command shell will treat them as a single token (I think that will work), or the spaces need to be escaped (I know that will work). In java, to include a single \ in a literal String, you need to escape the escape character, which is why I think two \\ are needed in the String, so that one will survive to be passed on to the exec command.
� {�