问题
I am reviewing a number of different java programs and am trying to work out how I can update the reference to the program name once only instead of twice. Is there a way to use a variable in a single terminal command? :S
The command I'm trying to improve is of this form:
javac Main.java && java Main
I only want to change the reference to Main once instead of typing it twice each time.
回答1:
You can do it with one line like this:
PC=com/mycompany/Main && CN=$(echo $PC | tr / .) && javac $PC.java && java $CN
This will work even if you have a package name as it will automatically replace / with . to build properly the full qualified name of your class. In the example above it will compile the class com/mycompany/Main.java then launch com.mycompany.Main
PC: Refers to the relative path of your class without .java, this what you will need to change
CN: Refers to the full qualified name of your class automatically built from the previous path
回答2:
You could set it as an environment variable. Something like,
export CLS=Main # Change Main once
javac $CLS.java && java $CLS # Will use "Main"
回答3:
Sometimes the simplest approach is best. It sounds like you have a bunch of programs to compile and run. I would suggest you put those names into a text file, like this:
Main
Foo
Bar
and then use some search and replace in the editor to make the text like this:
javac Main.java && java Main
javac Foo.java && java Foo
javac Bar.java && java Bar
|Then just select the lines to run and paste them into the terminal.
Of course, it depends on your expected workflow, but sometimes the simplest is the best.
来源：https://stackoverflow.com/questions/37745334/how-to-reference-main-once-only-in-this-ubuntu-terminal-command-javac-main-jav