Thread: Exit status 15 View Single Post
2020-10-15, 13:00   #6
storm5510
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Aug 2009

19·101 Posts

Quote:
 Originally Posted by kruoli Yes! If it finds the number itself: Code: ~$echo 2047 | ecm -one 1000 GMP-ECM 7.0.4 [configured with GMP 6.2.0, --enable-asm-redc] [ECM] Input number is 2047 (4 digits) Using B1=1000, B2=51606, polynomial x^1, sigma=1:2307810929 Step 1 took 1ms ********** Factor found in step 1: 2047 Found input number N ~$ echo $? 8 If it finds a factor and the cofactor is prime (maybe PRP): Code: ~$ echo 2047 | ecm -one 1 GMP-ECM 7.0.4 [configured with GMP 6.2.0, --enable-asm-redc] [ECM] Input number is 2047 (4 digits) Using B1=1, B2=12, polynomial x^1, sigma=1:309160743 Step 1 took 0ms Step 2 took 0ms ********** Factor found in step 2: 23 Found prime factor of 2 digits: 23 Prime cofactor 89 has 2 digits ~$echo$? 14 If it finds a factor and the cofactor is composite: Code: ~$echo '2*(2^2047-1)' | ecm -one 1 GMP-ECM 7.0.4 [configured with GMP 6.2.0, --enable-asm-redc] [ECM] Input number is 2*(2^2047-1) (617 digits) ********** Factor found in step 1: 2 Found prime factor of 1 digits: 2 Composite cofactor (2*(2^2047-1))/2 has 617 digits ~$ echo \$? 6 I'd have to look into the code if there are other possibilities.
Interesting. Thank you for the reply.

I was looking for a way to incorporate this into a Windows batch file. Below is an example:

Quote:
 echo "2^1861-1" | ecm -c 100 -v -one 3 1e6 if %errorlevel% neq 0 goto errhandler
In this case, neq is "not equal to." Knowing the specific return value is not really necessary. The three examples above demonstrate that -one also works in a non-looping mode. I was wondering about this.