in reply to Favourite One-liners?

I always use Perl when I need to do some calculation.

$ perl -le 'print <arithmetic expression here>'

The debugger is handy for iterative calculations:

$ perl -de0

Update - tip: Be careful with constructs like:

print (5 + 4) * 3;

This is equivalent to (print 5 + 4) * 3, probably not what you want.

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Re^2: Favourite One-liners?
by kaif (Friar) on Jun 28, 2005 at 14:21 UTC

    My most common one-liner, which accomplishes the "arithmetic evaluation" goal, is perl -ple'$_="> ".eval' (Déjà vu?)

      Other than the inherent awesomeness of producing a Perl REPL in under 25 characters, I don't see why one would prefer this one-liner to the even shorter

      perl -de1
      True, with the debugger one has to suffer the aggravation of having to prepend p or x to expressions if one wants to see the evaluated output, but in return one gets plenty of features like (off the top of my head):
      1. Readline with history (this one alone saves so much typing that it more than compensates for having to type those extra p's and x's);
      2. The option of paged output;
      3. The Joy of x, including not only pretty printing of complex data structures (with optional paging), but also the ability to specify the depth the pretty-printing;

      the lowliest monk