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.
BSD October 10, 2002 BSD