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	joko	1.13	/* $Id: prime.c,v 1.12 2006/05/13 12:35:32 joko Exp $ */
2	joko	1.5
3	joko	1.1	#include <stdio.h>
4	joko	1.6	#include <stdlib.h>
5			#include <limits.h>
6	joko	1.9	#include <errno.h>
7	joko	1.3
8	joko	1.13	#ifdef _MSC_VER
9			#define snprintf _snprintf
10			#endif
11
12	joko	1.6	#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	joko	1.5	#define PRINTERROR(message) fprintf(stderr, "ERROR: %s\n", message)
18	joko	1.10	#define PRINTWARNING(message) fprintf(stderr, "WARNING: %s\n", message)
19	joko	1.4
20	joko	1.11	#define MAX_LINE_LENGTH 80
21
22
23	joko	1.5	/* check for prime number */
24	joko	1.6	BOOL is_prime(long int number)
25	joko	1.1	{
26	joko	1.4	int i;
27	joko	1.7
28	joko	1.9	/* negative values, 0 and 1 are never prime numbers */
29	joko	1.7	if (number < 2) return FALSE;
30
31			/* check all numbers 2..sqrt(number) for being a prime number */
32	joko	1.4	for (i=2; i*i <= number; i++) {
33			if ((number % i) == 0)
34	joko	1.6	return FALSE;
35			}
36			return TRUE;
37			}
38
39	joko	1.7	/* convert from string to long int, with error checking */
40	joko	1.6	long int convert_number(const char *nptr) {
41	joko	1.9
42			char * endptr;
43			long int number = strtol(nptr, &endptr, 10);
44	joko	1.10
45			errno = 0;
46	joko	1.9
47			/* invalid characters? */
48			if (*endptr != '\0') {
49			char message[254];
50	joko	1.12	snprintf(message, 256, "Could not convert '%s' to a valid (integer) number.", nptr);
51	joko	1.9	PRINTERROR(message);
52			exit(EXIT_FAILURE);
53			}
54
55			/* invalid range? */
56			/* if (number == LONG_MAX \|\| number == LONG_MIN) { */
57			if (errno == ERANGE) {
58	joko	1.7	char message[254];
59	joko	1.8	snprintf(message, 256, "Number is not in range of 'long int': %s", nptr);
60	joko	1.7	PRINTERROR(message);
61	joko	1.9	exit(EXIT_FAILURE);
62	joko	1.4	}
63	joko	1.9
64			return number;
65
66	joko	1.1	}
67	joko	1.3
68	joko	1.1	int main(int argc, char * argv[])
69			{
70	joko	1.4
71			if (argc == 1) {
72	joko	1.6	PRINTERROR("No arguments given.");
73	joko	1.9	exit(EXIT_FAILURE);
74	joko	1.4	}
75
76	joko	1.5	/* (3) range mode */
77	joko	1.4	if (argc > 2) {
78	joko	1.7	long int i, j;
79	joko	1.9	i = convert_number(argv[1]);
80	joko	1.7	j = convert_number(argv[2]);
81	joko	1.9	for (i; i< j; i++) {
82	joko	1.1	PRINTPRIME(i);
83			}
84	joko	1.4
85	joko	1.5	/* other modes */
86	joko	1.4	} else {
87
88	joko	1.5	/* try to open file for reading */
89	joko	1.4	FILE * fp = fopen(argv[1], "r");
90
91	joko	1.5	/* (1) test-single-number mode: first argument is not a filename */
92	joko	1.4	if (fp == NULL) {
93	joko	1.7	long int number = convert_number(argv[1]);
94			PRINTPRIME(number);
95	joko	1.4
96	joko	1.5	/* (2) file mode: read numbers from file */
97	joko	1.4	} else {
98	joko	1.11	char line[MAX_LINE_LENGTH + 1];
99	joko	1.10	long int number;
100	joko	1.11	int line_length;
101			long int line_no = 0;
102			while (fgets(line, MAX_LINE_LENGTH + 1, fp)) {
103	joko	1.10
104			/* count line number (for warnings) */
105	joko	1.11	line_no++;
106	joko	1.10
107	joko	1.11	line_length = strlen(line);
108
109	joko	1.10	/* skip empty lines */
110	joko	1.11	if (strlen(line) < 2) continue;
111	joko	1.10
112			/* line handling: policy = skip exceeding lines */
113
114			/* line exceeds max length */
115	joko	1.11	if (line_length == MAX_LINE_LENGTH && line[line_length-1] != '\n') {
116	joko	1.10	char message[254];
117	joko	1.11	snprintf(message, 256, "Line too long (max %i chars) in line number: %i", MAX_LINE_LENGTH, line_no);
118	joko	1.10	PRINTWARNING(message);
119
120	joko	1.11	/* eat all characters until newline or EOF */
121			while (1) {
122			int charcode = fgetc(fp);
123			if (charcode == 10 \|\| charcode == EOF) break;
124			}
125	joko	1.10
126			/* skip this line from prime calculation */
127			continue;
128			}
129
130	joko	1.11	/* 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	joko	1.7	PRINTPRIME(number);
138	joko	1.11
139	joko	1.5	}
140	joko	1.1	fclose(fp);
141			}
142			}
143			}
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