我会在使用java启动进程之前添加一个umask,但java进程api(我使用java 9)不提供设置umask的方法。
我尝试通过执行umask来运行一个进程,该值的值允许我创建但不能读取(0644)。它不起作用......
Optional<String> umask = ProcessUtil.getUmask();
if (!umask.isPresent()) {
this.restartOnFail();
return;
}
ProcessUtil.setUmask(parent.config.umask);
this.timeAtLaunch = System.currentTimeMillis();
this.status = ProcessStatus.LAUNCHING;
this.process = pb.start();
this.onExitProcess();
ProcessUtil.setUmask(umask.get());
setUmask代码是:
public static void setUmask(String mask) {
try {
String[] commands = {"umask", mask};
Process exec = Runtime.getRuntime().exec(commands);
exec.waitFor();
} catch (Exception e) {
Server.global.logErr("Impossible to set umask for %s.", mask);
}
}
我试图这样做但似乎无法工作(我启动了一个创建文件并读取它的进程,它应该只创建它并在读取时发出错误。)因为进程创建了一个文件,没有umask设置的权限。他能够阅读该文件,这不应该发生......
我创建了一个ready runnable类:
import java.io.*;
public class StackOverFlowTest {
public static void setUmask(String mask) {
try {
String[] commands = {"umask", mask};
Process exec = Runtime.getRuntime().exec(commands);
exec.waitFor();
} catch (Exception e) {
e.printStackTrace();
}
}
public static void runCommand(String [] command) throws IOException, InterruptedException {
Runtime rt = Runtime.getRuntime();
Process proc = rt.exec(command);
BufferedReader stdInput = new BufferedReader(new InputStreamReader(proc.getInputStream()));
BufferedReader stdError = new BufferedReader(new InputStreamReader(proc.getErrorStream()));
String s = null;
while ((s = stdInput.readLine()) != null) {
System.out.println("stdout: " + s);
}
while ((s = stdError.readLine()) != null) {
System.out.println("stderr: " + s);
}
proc.waitFor();
}
public static void main(String[] args) {
setUmask("0644"); // set this permission -----w--w-
String[] create = {"touch", "file.stackoverflow"};
String[] read = {"cat", "file.stackoverflow"};
try {
runCommand(create);
runCommand(read);
} catch (Exception e) {
e.printStackTrace();
}
}
}
当cat启动时,这段代码实际上没有显示任何错误,这是一个问题!
(对不起我的英文)
所以有人有提示启动流程以及使用java的一些权限吗?