Ubuntu – find: missing argument to -exec

bashfindjava

The following works from the terminal no problem

find testDir -type f -exec md5sum {} \;

Where testDir is a directory that contains some files (for example file1, file2 and file3).

However, if I run this from a bash script or from Java using something like

Runtime rt = Runtime.getRuntime();
Process pr = rt.exec("find testDir -type f -exec md5sum {} \\;");

I get the following error

find: missing argument to `-exec'

Any ideas?

UPDATE: This was answered correctly over on stackoverflow. I will close the question here. https://stackoverflow.com/questions/10704889/java-execute-command-line-program-find-returns-error

Best Answer

The \ in -exec md6sum {} \; is necessary to prevent the shell from interpreting the ; character as command separator. If Java does not execute the command in a shell, try removing the escaping \\ so that the code becomes:

Runtime rt = Runtime.getRuntime();
Process pr = rt.exec("find testDir -type f -exec md5sum {} ;");

I have just confirmed this behavior with the next test program:

import java.io.*;
class Xx {
    public static void main(String args[]) throws Exception {
        Process p = Runtime.getRuntime().exec("/bin/echo \\;");
        InputStream in = p.getInputStream();
        int c;
        while ((c=in.read()) != -1)
            System.out.write((char)c);
        p.waitFor();
    }
}

Compiled with javac Xx.java, java Xx outputs \;. If I remove the \\, it'll print ; as expected.

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