1 |
|
/* $Id$ */ |
2 |
|
|
3 |
#include <stdio.h> |
#include <stdio.h> |
4 |
#define PRINTPRIME(x) if(prime(x)) printf("%i\n", x) |
#include <stdlib.h> |
5 |
|
#include <limits.h> |
6 |
|
#include <errno.h> |
7 |
|
|
8 |
|
#define BOOL int |
9 |
|
#define TRUE 1 |
10 |
|
#define FALSE 0 |
11 |
|
|
12 |
int prime(int number) |
#define PRINTPRIME(x) if (is_prime(x)) printf("%i\n", x) |
13 |
|
#define PRINTERROR(message) fprintf(stderr, "ERROR: %s\n", message) |
14 |
|
#define PRINTWARNING(message) fprintf(stderr, "WARNING: %s\n", message) |
15 |
|
|
16 |
|
/* check for prime number */ |
17 |
|
BOOL is_prime(long int number) |
18 |
{ |
{ |
19 |
int i; |
int i; |
20 |
for(i=2;i*i<=number;i++){ |
|
21 |
if((number%i) == 0) |
/* negative values, 0 and 1 are never prime numbers */ |
22 |
return 0; |
if (number < 2) return FALSE; |
23 |
} |
|
24 |
return 1; |
/* check all numbers 2..sqrt(number) for being a prime number */ |
25 |
|
for (i=2; i*i <= number; i++) { |
26 |
|
if ((number % i) == 0) |
27 |
|
return FALSE; |
28 |
|
} |
29 |
|
return TRUE; |
30 |
|
} |
31 |
|
|
32 |
|
/* convert from string to long int, with error checking */ |
33 |
|
long int convert_number(const char *nptr) { |
34 |
|
|
35 |
|
char * endptr; |
36 |
|
long int number = strtol(nptr, &endptr, 10); |
37 |
|
|
38 |
|
errno = 0; |
39 |
|
|
40 |
|
/* invalid characters? */ |
41 |
|
if (*endptr != '\0') { |
42 |
|
char message[254]; |
43 |
|
snprintf(message, 256, "Could not convert '%s' to a valid number.", nptr); |
44 |
|
PRINTERROR(message); |
45 |
|
exit(EXIT_FAILURE); |
46 |
|
} |
47 |
|
|
48 |
|
/* invalid range? */ |
49 |
|
/* if (number == LONG_MAX || number == LONG_MIN) { */ |
50 |
|
if (errno == ERANGE) { |
51 |
|
char message[254]; |
52 |
|
snprintf(message, 256, "Number is not in range of 'long int': %s", nptr); |
53 |
|
PRINTERROR(message); |
54 |
|
exit(EXIT_FAILURE); |
55 |
|
} |
56 |
|
|
57 |
|
return number; |
58 |
|
|
59 |
} |
} |
60 |
|
|
61 |
int main(int argc, char * argv[]) |
int main(int argc, char * argv[]) |
62 |
{ |
{ |
63 |
int i, j; |
|
64 |
FILE * fp; |
if (argc == 1) { |
65 |
char num[11]; |
PRINTERROR("No arguments given."); |
66 |
if(argc > 2 ){ |
exit(EXIT_FAILURE); |
67 |
j=atoi(argv[2]); |
} |
68 |
for(i=atoi(argv[1]) ; i< j; i++){ |
|
69 |
|
/* (3) range mode */ |
70 |
|
if (argc > 2) { |
71 |
|
long int i, j; |
72 |
|
i = convert_number(argv[1]); |
73 |
|
j = convert_number(argv[2]); |
74 |
|
for (i; i< j; i++) { |
75 |
PRINTPRIME(i); |
PRINTPRIME(i); |
76 |
} |
} |
77 |
}else { |
|
78 |
fp=fopen(argv[1], "r"); |
/* other modes */ |
79 |
if(fp==NULL){ |
} else { |
80 |
PRINTPRIME(atoi(argv[1])); |
|
81 |
}else{ |
/* try to open file for reading */ |
82 |
while(fgets(num, 11, fp)) |
FILE * fp = fopen(argv[1], "r"); |
83 |
PRINTPRIME(atoi(num)); |
|
84 |
|
/* (1) test-single-number mode: first argument is not a filename */ |
85 |
|
if (fp == NULL) { |
86 |
|
long int number = convert_number(argv[1]); |
87 |
|
PRINTPRIME(number); |
88 |
|
|
89 |
|
/* (2) file mode: read numbers from file */ |
90 |
|
} else { |
91 |
|
char entry[81]; |
92 |
|
long int number; |
93 |
|
long int lineno = 0; |
94 |
|
while (fgets(entry, 81, fp)) { |
95 |
|
|
96 |
|
/* count line number (for warnings) */ |
97 |
|
lineno++; |
98 |
|
|
99 |
|
/* skip empty lines */ |
100 |
|
if (strlen(entry) < 2) continue; |
101 |
|
|
102 |
|
/* line handling: policy = skip exceeding lines */ |
103 |
|
|
104 |
|
/* if last char is newline, strip it */ |
105 |
|
if (entry[strlen(entry)-1] == '\n') { |
106 |
|
entry[strlen(entry)-1] = '\0'; |
107 |
|
|
108 |
|
/* line exceeds max length */ |
109 |
|
} else { |
110 |
|
char message[254]; |
111 |
|
snprintf(message, 256, "Line too long (max 80 chars) in line number: %i", lineno); |
112 |
|
PRINTWARNING(message); |
113 |
|
|
114 |
|
/* eat all characters until newline */ |
115 |
|
while (fgetc(fp) != 10); |
116 |
|
|
117 |
|
/* skip this line from prime calculation */ |
118 |
|
continue; |
119 |
|
} |
120 |
|
|
121 |
|
number = convert_number(entry); |
122 |
|
PRINTPRIME(number); |
123 |
|
} |
124 |
fclose(fp); |
fclose(fp); |
125 |
} |
} |
126 |
} |
} |