Retrieving Expo from pXXXXXX file

[Uncwilly]

I was checking my prime directory (it ain't a folder), and discovered a p and a q file. Both ar efrom the same expo. Problem is, which one? I know that the save file name is part hex and part is decimal(?). How do I tell how much/which it is. That way I can save the test. In know that it is not a current expo, because I am only doing TF's through the V5 server on this machine. My prime.log is full of only the TF info.

[ckdo]

Learning by doing *g* ... I have the following save files:

-rw-r--r-- 1 kossy kossy  5752036 2008-07-27 08:51 m0L15153
-rw-r--r-- 1 kossy kossy 12501786 2008-08-07 09:06 m0L15159
-rw-r--r-- 1 kossy kossy 12277330 2008-08-06 18:33 m0L15237
-rw-r--r-- 1 kossy kossy  5751968 2008-08-06 18:24 q0L15201
-rw-r--r-- 1 kossy kossy  4275204 2008-08-06 18:24 qY201081
-rw-r--r-- 1 kossy kossy  4275216 2008-08-03 18:56 qY201177
-rw-r--r-- 1 kossy kossy  4275236 2008-08-07 07:06 qY201333
-rw-r--r-- 1 kossy kossy  4275248 2008-08-05 08:04 qY201417

The "qY" ones are for 4 exponents in the 34M range.
The "[mq]0L" ones are for 4 exponents in the 46M range.

So, if the save file name has a letter in 2nd place, take that letter. Add 9 to its position in the alphabet ("Y" is the 25th letter. 25+9=34). Append the numbers to get the exponent. (Here: 34201081, 34201177, 34201333, 34201417).

If, however, the letter is in 3rd place, take the letter. Add 34 to its position in the alphabet ("L" is the 12th letter. 12+34=46). Append the numbers (including the one in 2nd place) to get the exponent. (Here: 46015153, 46015159, 46015201, 46015237).

Very low exponents and very high ones (90M+ in my case) have the actual exponent as part of the file name.

Question to insiders: Why is it "add 34" and not "add 35"? There's 26 letters and 9 numbers (I can see why 0 is exempt), so it appears the naming scheme was changed too early...

[Uncwilly]

Originally Posted by ckdo

If, however, the letter is in 3rd place, take the letter. Add 34 to its position in the alphabet ("L" is the 12th letter. 12+34=46). Append the numbers (including the one in 2nd place) to get the exponent. (Here: 46015153, 46015159, 46015201, 46015237).

Question to insiders: Why is it "add 34" and not "add 35"? There's 26 letters and 9 numbers (I can see why 0 is exempt), so it appears the naming scheme was changed too early...

Thanks! My files where p9F9xxxx, and I didn't know if it was a double or a first time. Having an L makes one know it is not hex.

Maybe someone can add this and other details like: http://www.mersenneforum.org/showthread.php?t=10351
to the wiki