I spy with my little eye a number beginning with n++

Question

If you have ever travelled with kids more than about 20 minutes, you will have no doubt heard cries of "Are we there yet?" and "How much further?"

So we play games like "I Spy" to help pass the time as the miles go by.

There is a variation on "I Spy" whereby instead of spotting arbitrary named things, you must spot integers in strictly ascending order. Numbers are everywhere - licence plates, street names and numbers, street signs, adverts and so on - the list goes on; so this would appear to be a trivial game, so there are some restrictions to make this more challenging*:

• Each number must be spied in isolation - if the next number you need to spy is 7 and you see house number 17 then this does not count. However license plate 7ABC123 would be OK.
• In general, numbers may be considered "in isolation" if they are separated by any non digit separator, though there are some exceptions
• Fractions cannot be used. For example if you see a road sign saying "Albuquerque ¾ mile" (or even "Albuquerque 3/4 mile") you would not be able to spy either the "3" or the "4"
• Conversely if you see a date written as "3/4/2015" you may spy any of the "3", "4" or "2015"
• Decimals are a bit tricky. If you see "Ford Escort 1.3 litre", the 1.3 here counts a non-integer and the "1" and "3" parts cannot be used in isolation. However if you see "Ford Mustang 5.0 liter", you may spy this as a 5, because even though 5.0 is written as a decimal it is in fact a whole number.
• You may only spy numbers seen outside of the vehicle - so the ascending seconds of a your car's digital clock may not be spied. If you are lucky enough to see such a clock outside of the vehicle, then you may spy those ascending seconds until you can no longer see them (or they wrap to the next minute)
• You may see descending countdown seconds at a pedestrian crossing. Because numbers must be spied in ascending order, you will only be able to spy at most one number per pedestrian crossing.
• Numbers with leading zeros can be spied - for example the "020" in a London phone number would be acceptable as 20.

Challenge

The kids have already got bored of this game, so they want a program to play it for them. This program must do the following:

• Read input from an unbounded stream. This will most likely be STDIN or equivalent pipe, though (theoretically at least) something like a TCP session could be used. Function parameters or command-line options generally won't work as there will be limits to how much data is passed. However some kind of pointer or reference to an unbounded stream would be OK.
• The input stream will consist of random printable ASCII characters, as generated by tr -dc '[:print:]' < /dev/urandom on Linux. The input will generally not have newlines (these are control characters and not printable), so the input will effectively be one unbounded-length line.
• Spy ascending integers appearing in the stream starting at 0. This spying is subject the rules of the game above. In particular:
  • Numbers may only be spied if they are isolated, i.e. separated by non-digits
  • Numbers with leading zeros must be spied
  • No numbers may be spied from a substring <sep>n/m<sep>, where <sep> is any legal separator other than /
  • Decimals of the form <sep>n.0*<sep> (where 0* indicates 0 or more zeros) should be spied, but decimals with non-zero fractional parts should not be spied. Numbers in dotted decimals such as IP addresses where there is more than one . should be spied.
• For output, we need to keep track of what we have spied to so far. Every spied number should be output when it is spied. However we don't want to see a long stream of ascending numbers, so each number output must overwrite the previous one in some way. This may be achieved using escape characters, backspaces, output to some kind of textbox or any other method appropriate to your language.
• The program will continue spying until either the input stream ends, or until interrupted by the user (e.g. CTRL-c or button click)
• Your counter must be able to count up to at least 2^31-1. Above that, behavior may be undefined.

Examples

0 1 2 3 4 5 6 7 8 9 10   will spy up to 10
0a1b2c3d4e5f6g7h8i9j10   will spy up to 10
10 9 8 7 6 5 4 3 2 1 0   will spy up to 0
0 1 1 1 1 1 2 2 2 2 2    will spy up to 2
00 01 023 4 5            will spy up to 1
0 1 2 3/4 5              will spy up to 2
0 1 2 3/4/2015 5 6       will spy up to 6
0 1 2 3.1415 4 5 6       will spy up to 2
0 1 2 3.000 4 5 6        will spy up to 6
0 1 2 192.168.0.3 4      will spy up to 4
Output from `tr -dc '[:print:]' < /dev/urandom` or equivalent will spy up forever (or until interrupted)

---

*This game is harder than you might think - I tried it yesterday driving through the Bay Area for 2 hours and only got as far as 14.

Answer 1

sh, 170

tr -cs 0-9/. '\n'|
grep -vxEe"[0-9]+/[0-9]+" -e"[0-9]*\.0*[1-9][0-9]*"|
sed -r 's/^([0-9]*)\.0+$/0\1/'|
tr -s /. '\n'|
awk -vORS="\r" '$1==l{l=$1+1;print l-1}END{print "\n"}'