如何使用 grep 查找文件夹内的单词？

在 Windows 中，我会进行搜索以在文件夹中查找单词。同样，我想知道某个特定单词是否出现在包含许多子目录和文件的目录中。我对 grep 语法的搜索显示我必须指定文件名，即grep string filename.

Now, I do not know the filename, so what do I do? A friend suggested to do grep -nr string, but I don't know what this means and I got no results with it (there is no response until I issue a Ctrl + C).

grep -nr 'yourString*' .

末尾的点搜索当前目录。每个参数的含义：

-n            Show relative line number in the file
'yourString*' String for search, followed by a wildcard character
-r            Recursively search subdirectories listed
.             Directory for search (current directory)

grep -nr 'MobileAppSer*' .（会发现MobileAppServlet.java or MobileAppServlet.class or MobileAppServlet.txt; 'MobileAppASer*.*'是做同样事情的另一种方法。）

要检查更多参数，请使用man grep命令。