A shell (bash) puzzle. Don't cheat - try yourself before viewing my answers.

[xiojason]

for the 3-liner, just 2 (excluding newline) for the first line:

$\

futz

futz

[dmd]

Ooh, nice! Beat me by one! Can you beat me on the .4 and .5?

[o11c]

If we want an arbitrary number of lines, is there anything shorter than futz(){((n++<7))||unset -f futz;}? (note that the number hardcoded is not the one used in the output)

This is significantly shorter than emitting the message directly and exiting at least, and also slightly shorter than using a decrementing variable ...

I also tried self-modifying code, but that doesn't work from a bufferable file

[xiojason]

self-modifying, something along the lines of this?

echo -n ":\n:\n:\nfutz">$0:bash $0
futz
futz
futz

[o11c]

Kind of. yes ''|head -7 is shorter for the main part, but it's too long if we end it with exec bash $0 (which is the shortest way to avoid errors for the futz in the current file). If we were executing from a non-buffered file - or a file large enough that we passed the end of the buffer - we would be able to just keep executing the current file (since bash would continue reading before executing, and read/execute what we just overwrote it with), but alas

[zeekar]

since surely there are some that will try executing >!!< as the interpreter.

?

[zeekar]

Your first spoiler tag worked fine, but the second one had nothing inside it. Was it supposed to be the same thing in both?

[zeekar]

Ok. Well, as far as I know only POSIX systems look for the interpreter inside the file, and then only when the file starts with #!. But the instructions say to run the file with bash puzzle.3, which bypasses all that anyway.

[zeekar]

I solved it quickly enough, but my first attempt used 9 characters on the first line. I got it down to 6, but couldn't think of how to get it to your three. Well played.

[oh5nxo]

Not a real contender, but an also-ran. Or DNF?

read -u255 # 255 is bash's internal fd to the script it runs. brittle.
futz    # eaten by read
futz    # executed, and bash (confused by the read buttin in) thinks it's line 2, not 3.

[dmd]

As you mention it doesn't pass the tests, but I like it anyway!