FACTOR(6) BSD Games Manual FACTOR(6)
NAME
factor, primes -- factor a number, generate primes
SYNOPSIS
factor [-h] [number ...]
primes [-h] [start [stop]]
DESCRIPTION
The factor utility will factor positive integers. When a number is factored, it is printed, followed by a ':', and the list of factors on a
single line. Factors are listed in ascending order, and are preceded by a space. If a factor divides a value more than once, it will be
printed more than once.
When factor is invoked with one or more arguments, each argument will be factored.
When factor is invoked with no arguments, factor reads numbers, one per line, from standard input, until end of file or error. Leading
white-space and empty lines are ignored. Numbers may be preceded by a single '+'. Numbers are terminated by a non-digit character (such as
a newline). After a number is read, it is factored.
The primes utility prints primes in ascending order, one per line, starting at or above start and continuing until, but not including stop.
The start value must be at least 0 and not greater than stop. The stop value must not be greater than the maximum. The default and maximum
value of stop is 3825123056546413050.
When the primes utility is invoked with no arguments, start is read from standard input and stop is taken to be the maximum. The start value
may be preceded by a single '+'. The start value is terminated by a non-digit character (such as a newline).
DIAGNOSTICS
negative numbers aren't permitted
illegal numeric format
start value must be less than stop value
Result too large
BUGS
factor cannot handle the ``10 most wanted'' factor list, primes will not get you a world record.
primes is unable to list primes between 3825123056546413050 and 18446744073709551615 since it relies on strong pseudoprime tests after siev-
ing, and nobody has proven how many strong pseudoprime tests are required to prove primality for integers larger than 3825123056546413050.
BSD
October 10, 2002 BSD