Declaring main function/entry point in Julia
You could write a main
function and not call it from the top level of the file. To run the program from the command line you would use julia -L file.jl -e 'main(some,args)'
. The -L
switch tells Julia to load your file, and then -e
tells it to evaluate the following expression. There is also an -E
switch that evaluates and prints (I think of it as "evaluating out loud", since capital letters seem "loud").
This has a couple of advantages over C's main
or Python's if __name__ == "__main__"
:
You don't have to have a single entry point! You can evaluate any expression at all after loading your file, so you don't have to cram all your command line functionality into one function.
The calls you write use full Julia syntax, so often you can avoid parsing the arguments. Soemthing like
-e main(53)
callsmain
with the integer 53, no need foratoi
insidemain
.
When modules are loaded, if they have a function called __init__
it will be called. Does that help?