| 1 |
franky |
1.17 |
/* $Id: prime.c,v 1.16 2006/05/15 11:27:10 franky Exp $ */ |
| 2 |
joko |
1.5 |
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| 3 |
joko |
1.1 |
#include <stdio.h> |
| 4 |
joko |
1.6 |
#include <stdlib.h> |
| 5 |
franky |
1.14 |
#include <math.h> |
| 6 |
joko |
1.6 |
#include <limits.h> |
| 7 |
joko |
1.9 |
#include <errno.h> |
| 8 |
joko |
1.3 |
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| 9 |
joko |
1.13 |
#ifdef _MSC_VER |
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#define snprintf _snprintf |
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#endif |
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joko |
1.6 |
#define BOOL int |
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#define TRUE 1 |
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#define FALSE 0 |
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| 17 |
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#define PRINTPRIME(x) if (is_prime(x)) printf("%i\n", x) |
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joko |
1.5 |
#define PRINTERROR(message) fprintf(stderr, "ERROR: %s\n", message) |
| 19 |
joko |
1.10 |
#define PRINTWARNING(message) fprintf(stderr, "WARNING: %s\n", message) |
| 20 |
joko |
1.4 |
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| 21 |
joko |
1.11 |
#define MAX_LINE_LENGTH 80 |
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| 24 |
joko |
1.5 |
/* check for prime number */ |
| 25 |
joko |
1.6 |
BOOL is_prime(long int number) |
| 26 |
joko |
1.1 |
{ |
| 27 |
franky |
1.14 |
int i,sq; |
| 28 |
joko |
1.9 |
/* negative values, 0 and 1 are never prime numbers */ |
| 29 |
joko |
1.7 |
if (number < 2) return FALSE; |
| 30 |
franky |
1.14 |
sq=sqrt(number); |
| 31 |
joko |
1.7 |
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| 32 |
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/* check all numbers 2..sqrt(number) for being a prime number */ |
| 33 |
franky |
1.14 |
for (i=2; i <= sq; i++) { |
| 34 |
joko |
1.4 |
if ((number % i) == 0) |
| 35 |
joko |
1.6 |
return FALSE; |
| 36 |
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} |
| 37 |
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return TRUE; |
| 38 |
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} |
| 39 |
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| 40 |
joko |
1.7 |
/* convert from string to long int, with error checking */ |
| 41 |
franky |
1.14 |
long int convert_number(const char *nptr, BOOL warn) { |
| 42 |
joko |
1.9 |
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| 43 |
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char * endptr; |
| 44 |
franky |
1.15 |
long int number; |
| 45 |
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| 46 |
franky |
1.16 |
errno = 0; |
| 47 |
franky |
1.15 |
number = strtol(nptr, &endptr, 10); |
| 48 |
joko |
1.9 |
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| 49 |
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/* invalid characters? */ |
| 50 |
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if (*endptr != '\0') { |
| 51 |
franky |
1.14 |
char message[256]; |
| 52 |
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snprintf(message, 255, "Could not convert '%s' to a valid (integer) number.", nptr); |
| 53 |
franky |
1.17 |
errno=EINVAL; |
| 54 |
franky |
1.14 |
if(warn) |
| 55 |
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PRINTWARNING(message); |
| 56 |
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else{ |
| 57 |
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PRINTERROR(message); |
| 58 |
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exit(EXIT_FAILURE); |
| 59 |
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} |
| 60 |
joko |
1.9 |
} |
| 61 |
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| 62 |
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/* invalid range? */ |
| 63 |
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/* if (number == LONG_MAX || number == LONG_MIN) { */ |
| 64 |
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if (errno == ERANGE) { |
| 65 |
franky |
1.14 |
char message[256]; |
| 66 |
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snprintf(message, 255, "Number is not in range of 'long int': %s", nptr); |
| 67 |
franky |
1.17 |
errno=EINVAL; |
| 68 |
franky |
1.14 |
if(warn) |
| 69 |
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PRINTWARNING(message); |
| 70 |
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else{ |
| 71 |
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PRINTERROR(message); |
| 72 |
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exit(EXIT_FAILURE); |
| 73 |
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} |
| 74 |
joko |
1.4 |
} |
| 75 |
joko |
1.9 |
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| 76 |
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return number; |
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| 78 |
joko |
1.1 |
} |
| 79 |
joko |
1.3 |
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| 80 |
joko |
1.1 |
int main(int argc, char * argv[]) |
| 81 |
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{ |
| 82 |
joko |
1.4 |
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| 83 |
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if (argc == 1) { |
| 84 |
joko |
1.6 |
PRINTERROR("No arguments given."); |
| 85 |
joko |
1.9 |
exit(EXIT_FAILURE); |
| 86 |
joko |
1.4 |
} |
| 87 |
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| 88 |
joko |
1.5 |
/* (3) range mode */ |
| 89 |
joko |
1.4 |
if (argc > 2) { |
| 90 |
joko |
1.7 |
long int i, j; |
| 91 |
franky |
1.14 |
i = convert_number(argv[1],FALSE); |
| 92 |
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j = convert_number(argv[2],FALSE); |
| 93 |
joko |
1.9 |
for (i; i< j; i++) { |
| 94 |
joko |
1.1 |
PRINTPRIME(i); |
| 95 |
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} |
| 96 |
joko |
1.4 |
|
| 97 |
joko |
1.5 |
/* other modes */ |
| 98 |
joko |
1.4 |
} else { |
| 99 |
franky |
1.14 |
int err; |
| 100 |
joko |
1.5 |
/* try to open file for reading */ |
| 101 |
joko |
1.4 |
FILE * fp = fopen(argv[1], "r"); |
| 102 |
franky |
1.14 |
err=errno; |
| 103 |
franky |
1.17 |
errno=0; |
| 104 |
joko |
1.5 |
/* (1) test-single-number mode: first argument is not a filename */ |
| 105 |
joko |
1.4 |
if (fp == NULL) { |
| 106 |
franky |
1.14 |
long int number = convert_number(argv[1],TRUE); |
| 107 |
franky |
1.17 |
if(errno){ |
| 108 |
franky |
1.14 |
fprintf(stderr, "%s: %s\n", argv[1], strerror(err)); |
| 109 |
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return -1; |
| 110 |
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} |
| 111 |
joko |
1.7 |
PRINTPRIME(number); |
| 112 |
joko |
1.4 |
|
| 113 |
joko |
1.5 |
/* (2) file mode: read numbers from file */ |
| 114 |
joko |
1.4 |
} else { |
| 115 |
joko |
1.11 |
char line[MAX_LINE_LENGTH + 1]; |
| 116 |
joko |
1.10 |
long int number; |
| 117 |
joko |
1.11 |
int line_length; |
| 118 |
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long int line_no = 0; |
| 119 |
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while (fgets(line, MAX_LINE_LENGTH + 1, fp)) { |
| 120 |
joko |
1.10 |
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| 121 |
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/* count line number (for warnings) */ |
| 122 |
joko |
1.11 |
line_no++; |
| 123 |
joko |
1.10 |
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| 124 |
joko |
1.11 |
line_length = strlen(line); |
| 125 |
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| 126 |
joko |
1.10 |
/* skip empty lines */ |
| 127 |
joko |
1.11 |
if (strlen(line) < 2) continue; |
| 128 |
joko |
1.10 |
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| 129 |
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/* line handling: policy = skip exceeding lines */ |
| 130 |
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| 131 |
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/* line exceeds max length */ |
| 132 |
joko |
1.11 |
if (line_length == MAX_LINE_LENGTH && line[line_length-1] != '\n') { |
| 133 |
joko |
1.10 |
char message[254]; |
| 134 |
joko |
1.11 |
snprintf(message, 256, "Line too long (max %i chars) in line number: %i", MAX_LINE_LENGTH, line_no); |
| 135 |
joko |
1.10 |
PRINTWARNING(message); |
| 136 |
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| 137 |
joko |
1.11 |
/* eat all characters until newline or EOF */ |
| 138 |
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while (1) { |
| 139 |
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int charcode = fgetc(fp); |
| 140 |
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if (charcode == 10 || charcode == EOF) break; |
| 141 |
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} |
| 142 |
joko |
1.10 |
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| 143 |
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/* skip this line from prime calculation */ |
| 144 |
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continue; |
| 145 |
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} |
| 146 |
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| 147 |
joko |
1.11 |
/* if last char is newline, strip it */ |
| 148 |
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if (line[line_length-1] == '\n') { |
| 149 |
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line[line_length-1] = '\0'; |
| 150 |
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} |
| 151 |
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| 152 |
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/* finally: prime number calculation and output */ |
| 153 |
franky |
1.14 |
number = convert_number(line,FALSE); |
| 154 |
joko |
1.7 |
PRINTPRIME(number); |
| 155 |
joko |
1.11 |
|
| 156 |
joko |
1.5 |
} |
| 157 |
joko |
1.1 |
fclose(fp); |
| 158 |
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} |
| 159 |
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} |
| 160 |
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} |