从Java启动Terminal时修改PATH

Question

我使用以下Java代码来启动终端:

final ProcessBuilder processBuilder = new ProcessBuilder("/usr/bin/open", "-b",
                                                         "com.apple.Terminal",
                                                         "/Volumes");
final Map<String, String> environment = processBuilder.environment();
final String path = environment.get("PATH");
environment.put("PATH", "/mypath" + File.pathSeparator + path);
final Process process = processBuilder.start();
process.waitFor();

这会导致打开终端窗口,但似乎忽略了PATH的修改:

Volumes$ echo $PATH
/usr/bin:/bin:/usr/sbin:/sbin:/usr/local/bin

这个问题似乎与我如何启动终端有关.通过修改环境变量启动其他应用程序可以正常工作.

如何启动终端以便它接受我的环境变量修改,即使终端已经打开？

Answer 1

在这种特殊情况下，您可以通过使用 AppleScript 打开终端来伪造它：

final ProcessBuilder processBuilder = new ProcessBuilder(
      "/usr/bin/osascript", "-e");
final Map<String, String> environment = processBuilder.environment();
final String path = environment.get("PATH");
processBuilder.command().add("tell application \"Terminal\" to do script \"" +
    "cd /Volumes ; export PATH=\\\"/mypath:" + path + "\\\\"\"");
final Process process = processBuilder.start();
process.waitFor();

如果您想填充cd目录和PATH用户提供的参数中的值，那么我会考虑使用on run让脚本接受参数，并使用quoted form of来避免引用时出现任何潜在问题：

final ProcessBuilder processBuilder = new ProcessBuilder("/usr/bin/osascript",
   "-e", "on run argv",
   "-e", "  tell application \"Terminal\" to do script "
            + "\"cd \" & quoted form of item 1 of argv & \" ; "
            + "export PATH=\" & quoted form of item 2 of argv",
   "-e", "end run");

// create a File and use getAbsolutePath to resolve any relative paths
// against this Java process's working directory.
File cdDir = new File(dirParam);

// this argument will be "item 1 of argv" to the AppleScript
processBuilder.command().add(cdDir.getAbsolutePath());

final Map<String, String> environment = processBuilder.environment();
final String path = environment.get("PATH");

File pathPrefix = new File(pathParam);
// and this will be "item 2 of argv"
processBuilder.command().add(
      pathPrefix.getAbsolutePath() + File.pathSeparator + path);

final Process process = processBuilder.start();
process.waitFor();

如果您无法getAbsolutePath在 Java 端实现该技巧，但仍希望相对路径（相对于 的当前目录osascript）起作用，那么您需要这样的技巧：

final ProcessBuilder processBuilder = new ProcessBuilder("/usr/bin/osascript",
   "-e", "on run argv",
   "-e", "  set currentdir to (do shell script \"pwd\")",
   "-e", "  set currentpath to (do shell script \"echo $PATH\")",
   "-e", "  tell application \"Terminal\" to do script \""
            + "cd \" & quoted form of currentdir & \" ; ""
            + "cd \" & quoted form of item 1 of argv & \" ; "
            + "export PATH=\" & quoted form of currentpath",
   "-e", "end run",
   dirParam);

final Map<String, String> environment = processBuilder.environment();
final String path = environment.get("PATH");
environment.put("PATH", pathParam + File.pathSeparator + path);

final Process process = processBuilder.start();
process.waitFor();

这有点像俄罗斯娃娃 - 我们osascript从 Java 执行，Java 又运行自己的子 shell 来执行操作pwd并将echo $PATH当前工作目录的值和osascript 进程的PATH变量放入 AppleScript 变量中，然后将其注入进入新航站楼。通过首先对“当前”目录执行 a 操作，然后对指定的目录执行另一个操作，这将处理相对路径和绝对路径。cdcddirParam

最后请注意，osascript打印脚本的返回值，因此您应该确保在执行之前消耗了所有进程输出waitFor（或者如果您使用的是 Java 7，则可以使用processBuilder.redirectOutput(new File("/dev/null"))和 相同redirectError）。