factor(6) [netbsd man page]

FACTOR(6)							 BSD Games Manual							 FACTOR(6)

NAME

     factor -- factor a number

SYNOPSIS

     factor [number ...]

DESCRIPTION

     The factor utility factors integers larger than 1.  When a number is factored, it is printed, followed by a ``:'', and the list of (prime)
     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 +.  Integer less than 2 are rejected.  Numbers are terminated
     by a non-digit character (such as a newline).  After a number is read, it is factored.  Input lines must not be longer than LINE_MAX - 1
     (currently 2047) characters.

     By default, factor is compiled against the OpenSSL bignum implementation openssl_bn(3), which lets it handle arbitrarily large values.  (Note
     however that very large values can take a very long time to factor.) If factor is compiled without OpenSSL it is limited to the maximum value
     of unsigned long.

DIAGNOSTICS

     Out of range or invalid input results in an appropriate error message being written to standard error.

BSD
								   May 15, 2010 							       BSD

factor(1)						      General Commands Manual							 factor(1)

NAME

       factor, primes - factor a number, generate large primes

SYNOPSIS

       [number]

       [start[stop]]

DESCRIPTION

       If  no arguments are provided on the command line, waits for a number to be typed in.  If a positive number is typed, it factors the number
       and print its prime factors; each one is printed the proper number of times.  It then waits for another number.	exits if it  encounters  a
       zero or any non-numeric character.

       If an argument is provided on the command line, factors the number as above, then exits.

       Maximum time to factor is proportional to sqrt(n) and occurs when n is prime or the square of a prime.

       The largest number that can be dealt with by is 1.0e14.

       prints  prime numbers between a lower and upper bound.  If no arguments are provided on the command line, waits for two numbers to be typed
       in.  The first number is interpreted as the lower bound; the second as the upper bound.	All prime numbers in the resulting inclusive range
       are printed.

       If  start  is  specified, all primes greater than or equal to start are printed.  If both start and stop are given, all primes occurring in
       the inclusive range start through stop are printed.

       start and stop values must be integers represented as long integers.

       If the stop value is omitted in either case, runs either until overflow occurs or until it is stopped by typing the interrupt character.

       The largest number that can be dealt with by is	2,147,483,647.

DIAGNOSTICS

       Both commands print when the input is out of range, illegal characters are encountered, or when start is greater than stop.

EXAMPLES

       Print the prime factorization for the number 12:

       Print all prime numbers between 0 and 20:

																	 factor(1)