BSArch/01/prime.c

/* $Id: prime.c,v 1.12 2006/05/13 12:35:32 joko Exp $ */

#include <stdio.h>
#include <stdlib.h>
#include <limits.h>
#include <errno.h>

#ifdef _MSC_VER
#define snprintf _snprintf
#endif

#define BOOL int
#define TRUE 1
#define FALSE 0

#define PRINTPRIME(x) if (is_prime(x)) printf("%i\n", x)
#define PRINTERROR(message) fprintf(stderr, "ERROR: %s\n", message)
#define PRINTWARNING(message) fprintf(stderr, "WARNING: %s\n", message)

#define MAX_LINE_LENGTH 80


/* check for prime number */
BOOL is_prime(long int number)
{
        int i;
        
        /* negative values, 0 and 1 are never prime numbers */
        if (number < 2) return FALSE;
        
        /* check all numbers 2..sqrt(number) for being a prime number */
        for (i=2; i*i <= number; i++) {
                if ((number % i) == 0)
                        return FALSE;
        }
        return TRUE;
}

/* convert from string to long int, with error checking */
long int convert_number(const char *nptr) {
        
        char * endptr;
        long int number = strtol(nptr, &endptr, 10);

        errno = 0;
        
        /* invalid characters? */
        if (*endptr != '\0') {
                char message[254];
                snprintf(message, 256, "Could not convert '%s' to a valid (integer) number.", nptr);
                PRINTERROR(message);
                exit(EXIT_FAILURE);
        }
        
        /* invalid range? */
        /* if (number == LONG_MAX || number == LONG_MIN) { */
        if (errno == ERANGE) {
                char message[254];
                snprintf(message, 256, "Number is not in range of 'long int': %s", nptr);
                PRINTERROR(message);
                exit(EXIT_FAILURE);
        }
        
        return number;
        
}

int main(int argc, char * argv[])
{
        
        if (argc == 1) {
                PRINTERROR("No arguments given.");
                exit(EXIT_FAILURE);
        }
        
        /* (3) range mode */
        if (argc > 2) {
                long int i, j;
                i = convert_number(argv[1]);
                j = convert_number(argv[2]);
                for (i; i< j; i++) {
                        PRINTPRIME(i);
                }
        
        /* other modes */
        } else {

                /* try to open file for reading */
                FILE * fp = fopen(argv[1], "r");
                
                /* (1) test-single-number mode: first argument is not a filename */
                if (fp == NULL) {
                        long int number = convert_number(argv[1]);
                        PRINTPRIME(number);
                
                /* (2) file mode: read numbers from file */
                } else {
                        char line[MAX_LINE_LENGTH + 1];
                        long int number;
                        int line_length;
                        long int line_no = 0;
                        while (fgets(line, MAX_LINE_LENGTH + 1, fp)) {
                                
                                /* count line number (for warnings) */
                                line_no++;

                                line_length = strlen(line);
                                
                                /* skip empty lines */
                                if (strlen(line) < 2) continue;

                                /* line handling: policy = skip exceeding lines */
                                
                                /* line exceeds max length */
                                if (line_length == MAX_LINE_LENGTH && line[line_length-1] != '\n') {
                                        char message[254];
                                        snprintf(message, 256, "Line too long (max %i chars) in line number: %i", MAX_LINE_LENGTH, line_no);
                                        PRINTWARNING(message);
                                        
                                        /* eat all characters until newline or EOF */
                                        while (1) {
                                                int charcode = fgetc(fp);
                                                if (charcode == 10 || charcode == EOF) break;
                                        }
                                        
                                        /* skip this line from prime calculation */
                                        continue;
                                }
                                
                                /* if last char is newline, strip it */
                                if (line[line_length-1] == '\n') {
                                        line[line_length-1] = '\0';
                                }
                                
                                /* finally: prime number calculation and output */
                                number = convert_number(line);
                                PRINTPRIME(number);
                                
                        }
                        fclose(fp);
                }
        }
}
1	/* $Id: prime.c,v 1.12 2006/05/13 12:35:32 joko Exp $ */
2
3	#include <stdio.h>
4	#include <stdlib.h>
5	#include <limits.h>
6	#include <errno.h>
7
8	#ifdef _MSC_VER
9	#define snprintf _snprintf
10	#endif
11
12	#define BOOL int
13	#define TRUE 1
14	#define FALSE 0
15
16	#define PRINTPRIME(x) if (is_prime(x)) printf("%i\n", x)
17	#define PRINTERROR(message) fprintf(stderr, "ERROR: %s\n", message)
18	#define PRINTWARNING(message) fprintf(stderr, "WARNING: %s\n", message)
19
20	#define MAX_LINE_LENGTH 80
21
22
23	/* check for prime number */
24	BOOL is_prime(long int number)
25	{
26	int i;
27
28	/* negative values, 0 and 1 are never prime numbers */
29	if (number < 2) return FALSE;
30
31	/* check all numbers 2..sqrt(number) for being a prime number */
32	for (i=2; i*i <= number; i++) {
33	if ((number % i) == 0)
34	return FALSE;
35	}
36	return TRUE;
37	}
38
39	/* convert from string to long int, with error checking */
40	long int convert_number(const char *nptr) {
41
42	char * endptr;
43	long int number = strtol(nptr, &endptr, 10);
44
45	errno = 0;
46
47	/* invalid characters? */
48	if (*endptr != '\0') {
49	char message[254];
50	snprintf(message, 256, "Could not convert '%s' to a valid (integer) number.", nptr);
51	PRINTERROR(message);
52	exit(EXIT_FAILURE);
53	}
54
55	/* invalid range? */
56	/* if (number == LONG_MAX \|\| number == LONG_MIN) { */
57	if (errno == ERANGE) {
58	char message[254];
59	snprintf(message, 256, "Number is not in range of 'long int': %s", nptr);
60	PRINTERROR(message);
61	exit(EXIT_FAILURE);
62	}
63
64	return number;
65
66	}
67
68	int main(int argc, char * argv[])
69	{
70
71	if (argc == 1) {
72	PRINTERROR("No arguments given.");
73	exit(EXIT_FAILURE);
74	}
75
76	/* (3) range mode */
77	if (argc > 2) {
78	long int i, j;
79	i = convert_number(argv[1]);
80	j = convert_number(argv[2]);
81	for (i; i< j; i++) {
82	PRINTPRIME(i);
83	}
84
85	/* other modes */
86	} else {
87
88	/* try to open file for reading */
89	FILE * fp = fopen(argv[1], "r");
90
91	/* (1) test-single-number mode: first argument is not a filename */
92	if (fp == NULL) {
93	long int number = convert_number(argv[1]);
94	PRINTPRIME(number);
95
96	/* (2) file mode: read numbers from file */
97	} else {
98	char line[MAX_LINE_LENGTH + 1];
99	long int number;
100	int line_length;
101	long int line_no = 0;
102	while (fgets(line, MAX_LINE_LENGTH + 1, fp)) {
103
104	/* count line number (for warnings) */
105	line_no++;
106
107	line_length = strlen(line);
108
109	/* skip empty lines */
110	if (strlen(line) < 2) continue;
111
112	/* line handling: policy = skip exceeding lines */
113
114	/* line exceeds max length */
115	if (line_length == MAX_LINE_LENGTH && line[line_length-1] != '\n') {
116	char message[254];
117	snprintf(message, 256, "Line too long (max %i chars) in line number: %i", MAX_LINE_LENGTH, line_no);
118	PRINTWARNING(message);
119
120	/* eat all characters until newline or EOF */
121	while (1) {
122	int charcode = fgetc(fp);
123	if (charcode == 10 \|\| charcode == EOF) break;
124	}
125
126	/* skip this line from prime calculation */
127	continue;
128	}
129
130	/* if last char is newline, strip it */
131	if (line[line_length-1] == '\n') {
132	line[line_length-1] = '\0';
133	}
134
135	/* finally: prime number calculation and output */
136	number = convert_number(line);
137	PRINTPRIME(number);
138
139	}
140	fclose(fp);
141	}
142	}
143	}
MailToCvsAdmin">MailToCvsAdmin	ViewVC Help
Powered by ViewVC 1.1.26