如何扫描可执行文件的搜索路径

Question

在Java中是否可以通过shell命令获取文件的路径？

例如，当我在 Windows 命令提示符下键入 php -v 时，它会知道我指的是 C:\php\php.exe（对于我自己的计算机），因为我将它添加到系统 Path 变量中。是否可以在 Java 中做同样的事情？

我知道你可以从Java中获取Path环境变量并使用String.split(";")进行解析，但不知道有没有更直接的方法？

Answer 1

看看下面来自 JGit 库的代码 http://download.eclipse.org/jgit/site/3.7.1.201504261725-r/apidocs/org/eclipse/jgit/util/FS.html#searchPath(java.lang.String,%20java.lang.String...)

你可以实现类似的东西

/**
 * Searches the given path to see if it contains one of the given files.
 * Returns the first it finds. Returns null if not found or if path is null.
 *
 * @param path
 *            List of paths to search separated by File.pathSeparator
 * @param lookFor
 *            Files to search for in the given path
 * @return the first match found, or null
 * @since 3.0
 **/
protected static File searchPath(final String path, final String... lookFor) {
    if (path == null)
        return null;

    for (final String p : path.split(File.pathSeparator)) {
        for (String command : lookFor) {
            final File e = new File(p, command);
            if (e.isFile())
                return e.getAbsoluteFile();
        }
    }
    return null;
}

Answer 2

您也许可以使用来自my Java Command Prompt 的这段摘录做一些事情。

String cmd = "which "+<insert executable to find>; // linux
String cmd = "where "+<insert executable to find>; // windows

Process p = Runtime.getRuntime().exec(cmd);

BufferedReader stdInput = new BufferedReader(new InputStreamReader(p.getInputStream()));

BufferedReader stdError = new BufferedReader(new InputStreamReader(p.getErrorStream()));
// read the output from the command
while ((s = stdInput.readLine()) != null) {
    ref.log.setText(ref.log.getText()+s+"\n");
    ref.updateDisplay();
}
// read any errors from the attempted command
while ((s = stdError.readLine()) != null) {
    ref.log.setText(ref.log.getText()+s+"\n");
    ref.updateDisplay();
}

输出应该包含文件的路径。