When writing Common Lisp code, I use SLIME. In particular, I compile the buffer containing definitions of functions by using C-C C-k, and then switch to the REPL to run those functions. Putting executable code to run those functions in the buffer does not appear to work so well. If the code has bugs it can make a mess.
It would be handy to have a way to include code that doesn't get compiled in the buffer, but do get run from the command line, e.g. when doing
sbcl --script foo.lisp
If that were the case, I would not have to keep adding and removing code every time I wanted to run code from the command line. Does there exist such a condition?
This is analogous to the Python condition.
if __name__=='__main__':
which is false if a Python file is imported as a module, but true if it is run as a script.
This blog post entitled "Using SBCL for Common Lisp shell scripting", found by random Googling, has
;; If run from command line, the following if-test will succeed
(if (> (length sb-ext:*posix-argv*) 1)
;; Code that is executed from the command line only goes here
)
The code included indeed does not get run by the compiler inside SLIME, but it doesn't get run by sbcl --script either.
UPDATE: Thanks to Vsevolod Dyomkin for his helpful answer and the followups. Some notes about that answer follow, compiled from the comments to that answer. @Vsevolod, if you add these to your answer, I'll delete them.
First, I asked for a way to run code from the command line, but not from the interpreter. The supplied solution does more; it also gives a way to run code from the interpreter but not the command line.
The first step is to define a reader macro f