4
# mawk -f primes.awk [START] STOP
5
# find all primes between 2 and STOP
12
{ ustr = sprintf("usage: %s [start] stop", ARGV[0])
18
BEGIN { if (ARGC == 1 || ARGC > 3 ) usage()
19
if ( ARGC == 2 ) { start = 2 ; stop = ARGV[1]+0 }
21
if ( ARGC == 3 ) { start = ARGV[1]+0 ; stop = ARGV[2]+0 }
23
if ( start < 2 ) start = 2
24
if ( stop < start ) stop = start
26
prime[ p_cnt = 1 ] = 3 # keep primes in prime[]
28
# keep track of integer part of square root by adding
35
while ( test <= stop )
37
if ( test >= squares )
44
for ( i = 1 ; prime[i] <= root ; i++ )
45
if ( test % prime[i] == 0 ) # not prime
48
if ( flag ) prime[ ++p_cnt ] = test
55
for( i = 0 ; prime[i] < start ; i++) ;
57
for ( ; i <= p_cnt ; i++ ) print prime[i]