Java read file by command line, <(less than) symbol

Question

I am trying to read the filename by the command line,

This is command that our professor wants us to type:

java MultiBinaryClient xxxxxx.edu 6001 <         


        

Answer 1

Let's see what each fragment means. This is how we execute a Java class containing a main method:

java MultiBinaryClient

The only command-line arguments that are being passed to your program are these ones:

xxxxxx.edu 6001

And this snippet is not part of the expected arguments to the Java program:

< files.txt

It's just Unix shell syntax to specify that the contents of files.txt must be read into your program via the standard input.

Answer 2

You should escape the '<'

java MultiBinaryClient xxxxxx.edu 6001 \< files.txt

Answer 3

< is a redirection. The file will be streaming over stdin.

Answer 4

I know it's an old question, but I've had this problem recently. Here's what I've done to handle it:

Well, as the others said, the "<" redirects the file contents to stdin. If you want to use the file contents as program arguments, you can use xargs:

xargs -a FILE java JAVA_ARGS

or, more specifically:

xargs -a FILE java -cp CLASSPATH CLASS_WITH_MAIN_METHOD