Any computer progammers out there

rde

My apologies if I am posting this to the wrong board but I have a puzzle which is driving me bonkers. Moderators, feel free to move my post to a suitable forum.

In my spare time I do geocaching, a sort of high (ish) tech treasure hunt. For more information go here. One of my local caches has a puzzle to work out to get the co-ords for it. This involves working our some program code. I have supplied the code as a picture file enclosed. FYI the suggested parking co-ords are N 51° 41.989 W 002° 01.497 . If you would like to do the cache the page can be found here.

If anyone can explain to me what is going on I would appreciate it. An answer would be fantastic. You can check your answer here.

closed

it's shell script.

echo prints some text
cat copies the contents of a file
bc does some maths, scale=3 means to 3 decimal points
\c means don't start a new line
touch either creates an empty file, or updates the timestamp on a file
rm deletes a file
> creates a file containing the contents of the previous command
| (pipe) passes the output of the previous command to a new command
>> appends the previous output on the end of a file
tr translates (shifts) in this case any 0-9 numbers to 3-9, and 0-2
read reads data into a variable

the tr command is doing the decrypting

in the cat north2 line a 0 will become a 3, a 1 a 4, a 9 will become a 2 etc.

http://www.softpanorama.org/Tools/tr.shtml

rde

Many thanks Closed for the hints, I've managed to work it out. As you say it's the tr command that does the work.

Again many thanks!!

closed

and the subtraction/addition in the bc lines