|
| 1 | +/* |
| 2 | +cash.c |
| 3 | +Written by D'Arcy J.M. Cain |
| 4 | +
|
| 5 | +Functions to allow input and output of money normally but store |
| 6 | +and handle it as longs |
| 7 | +
|
| 8 | +Set tabstops to 4 for best results |
| 9 | +
|
| 10 | +A slightly modified version of this file and a discussion of the |
| 11 | +workings can be found in the book "Software Solutions in C" by |
| 12 | +Dale Schumacher, Academic Press, ISBN: 0-12-632360-7. |
| 13 | +
|
| 14 | +*/ |
| 15 | + |
| 16 | +#include <stdio.h> |
| 17 | +#include <string.h> |
| 18 | +#include <limits.h> |
| 19 | +#include <ctype.h> |
| 20 | +#include <locale.h> |
| 21 | + |
| 22 | +#ifdef TEST_MAIN |
| 23 | +# include <stdlib.h> |
| 24 | +# define palloc malloc |
| 25 | +#else |
| 26 | +# include <palloc.h> |
| 27 | +#endif |
| 28 | + |
| 29 | +#include "cash.h" |
| 30 | + |
| 31 | +/* when we go to 64 bit values we will have to modify this */ |
| 32 | +#define CASH_BUFSZ 24 |
| 33 | + |
| 34 | +#define TERMINATOR (CASH_BUFSZ - 1) |
| 35 | +#define LAST_PAREN (TERMINATOR - 1) |
| 36 | +#define LAST_DIGIT (LAST_PAREN - 1) |
| 37 | + |
| 38 | +/* function to convert a long to a dollars and cents representation */ |
| 39 | +const char * |
| 40 | +cash_out(long value) |
| 41 | +{ |
| 42 | + char *retbuf, buf[CASH_BUFSZ]; |
| 43 | + struct lconv *lc = localeconv(); |
| 44 | + int mod_group = *lc->mon_grouping; |
| 45 | + int comma = *lc->mon_thousands_sep; |
| 46 | + int points = lc->frac_digits; /* int_frac_digits? */ |
| 47 | + int minus = 0; |
| 48 | + int count = LAST_DIGIT; |
| 49 | + int point_pos; |
| 50 | + int comma_position = 0; |
| 51 | + |
| 52 | + /* frac_digits in the C locale seems to return CHAR_MAX */ |
| 53 | + /* best guess is 2 in this case I think */ |
| 54 | + if (points == CHAR_MAX) |
| 55 | + points = 2; |
| 56 | + |
| 57 | + point_pos = LAST_DIGIT - points; |
| 58 | + |
| 59 | + /* We're playing a little fast and loose with this. Shoot me. */ |
| 60 | + if (!mod_group || mod_group == CHAR_MAX) |
| 61 | + mod_group = 3; |
| 62 | + |
| 63 | + /* allow more than three decimal points and separate them */ |
| 64 | + if (comma) |
| 65 | + { |
| 66 | + point_pos -= (points - 1)/mod_group; |
| 67 | + comma_position = point_pos % (mod_group + 1); |
| 68 | + } |
| 69 | + |
| 70 | + /* we work with positive amounts and add the minus sign at the end */ |
| 71 | + if (value < 0) |
| 72 | + { |
| 73 | + minus = 1; |
| 74 | + value *= -1; |
| 75 | + } |
| 76 | + |
| 77 | + /* allow for trailing negative strings */ |
| 78 | + memset(buf, ' ', CASH_BUFSZ); |
| 79 | + buf[TERMINATOR] = buf[LAST_PAREN] = 0; |
| 80 | + |
| 81 | + while (value || count > (point_pos - 2)) |
| 82 | + { |
| 83 | + if (points && count == point_pos) |
| 84 | + buf[count--] = *lc->decimal_point; |
| 85 | + else if (comma && count % (mod_group + 1) == comma_position) |
| 86 | + buf[count--] = comma; |
| 87 | + |
| 88 | + buf[count--] = (value % 10) + '0'; |
| 89 | + value /= 10; |
| 90 | + } |
| 91 | + |
| 92 | + if (buf[LAST_DIGIT] == ',') |
| 93 | + buf[LAST_DIGIT] = buf[LAST_PAREN]; |
| 94 | + |
| 95 | + /* see if we need to signify negative amount */ |
| 96 | + if (minus) |
| 97 | + { |
| 98 | + retbuf = palloc(CASH_BUFSZ + 2 - count + strlen(lc->negative_sign)); |
| 99 | + |
| 100 | + /* Position code of 0 means use parens */ |
| 101 | + if (!lc->n_sign_posn) |
| 102 | + sprintf(retbuf, "(%s)", buf + count); |
| 103 | + else if (lc->n_sign_posn == 2) |
| 104 | + sprintf(retbuf, "%s%s", buf + count, lc->negative_sign); |
| 105 | + else |
| 106 | + sprintf(retbuf, "%s%s", lc->negative_sign, buf + count); |
| 107 | + } |
| 108 | + else |
| 109 | + { |
| 110 | + retbuf = palloc(CASH_BUFSZ + 2 - count); |
| 111 | + strcpy(retbuf, buf + count); |
| 112 | + } |
| 113 | + |
| 114 | + return retbuf; |
| 115 | +} |
| 116 | + |
| 117 | +/* convert a string to a long integer */ |
| 118 | +long |
| 119 | +cash_in(const char *s) |
| 120 | +{ |
| 121 | + long value = 0; |
| 122 | + long dec = 0; |
| 123 | + long sgn = 1; |
| 124 | + int seen_dot = 0; |
| 125 | + struct lconv *lc = localeconv(); |
| 126 | + int fpoint = lc->frac_digits; /* int_frac_digits? */ |
| 127 | + |
| 128 | + /* we need to add all sorts of checking here. For now just */ |
| 129 | + /* strip all leading whitespace and any leading dollar sign */ |
| 130 | + while (isspace(*s) || *s == '$') |
| 131 | + s++; |
| 132 | + |
| 133 | + /* a leading minus or paren signifies a negative number */ |
| 134 | + /* again, better heuristics needed */ |
| 135 | + if (*s == '-' || *s == '(') |
| 136 | + { |
| 137 | + sgn = -1; |
| 138 | + s++; |
| 139 | + } |
| 140 | + else if (*s == '+') |
| 141 | + s++; |
| 142 | + |
| 143 | + /* frac_digits in the C locale seems to return CHAR_MAX */ |
| 144 | + /* best guess is 2 in this case I think */ |
| 145 | + if (fpoint == CHAR_MAX) |
| 146 | + fpoint = 2; |
| 147 | + |
| 148 | + for (; ; s++) |
| 149 | + { |
| 150 | + /* we look for digits as long as we have less */ |
| 151 | + /* than the required number of decimal places */ |
| 152 | + if (isdigit(*s) && dec < fpoint) |
| 153 | + { |
| 154 | + value = (value * 10) + *s - '0'; |
| 155 | + |
| 156 | + if (seen_dot) |
| 157 | + dec++; |
| 158 | + } |
| 159 | + else if (*s == *lc->decimal_point && !seen_dot) |
| 160 | + seen_dot = 1; |
| 161 | + else |
| 162 | + { |
| 163 | + /* round off */ |
| 164 | + if (isdigit(*s) && *s >= '5') |
| 165 | + value++; |
| 166 | + |
| 167 | + /* adjust for less than required decimal places */ |
| 168 | + for (; dec < fpoint; dec++) |
| 169 | + value *= 10; |
| 170 | + |
| 171 | + return(value * sgn); |
| 172 | + } |
| 173 | + } |
| 174 | +} |
| 175 | + |
| 176 | + |
| 177 | +/* used by cash_words_out() below */ |
| 178 | +static const char * |
| 179 | +num_word(int value) |
| 180 | +{ |
| 181 | + static char buf[128]; |
| 182 | + static const char *small[] = { |
| 183 | + "zero", "one", "two", "three", "four", "five", "six", "seven", |
| 184 | + "eight", "nine", "ten", "eleven", "twelve", "thirteen", "fourteen", |
| 185 | + "fifteen", "sixteen", "seventeen", "eighteen", "nineteen", "twenty", |
| 186 | + "thirty", "fourty", "fifty", "sixty", "seventy", "eighty", "ninety" |
| 187 | + }; |
| 188 | + const char **big = small + 18; |
| 189 | + int tu = value % 100; |
| 190 | + |
| 191 | + /* deal with the simple cases first */ |
| 192 | + if (value <= 20) |
| 193 | + return(small[value]); |
| 194 | + |
| 195 | + /* is it an even multiple of 100? */ |
| 196 | + if (!tu) |
| 197 | + { |
| 198 | + sprintf(buf, "%s hundred", small[value/100]); |
| 199 | + return(buf); |
| 200 | + } |
| 201 | + |
| 202 | + /* more than 99? */ |
| 203 | + if (value > 99) |
| 204 | + { |
| 205 | + /* is it an even multiple of 10 other than 10? */ |
| 206 | + if (value % 10 == 0 && tu > 10) |
| 207 | + sprintf(buf, "%s hundred %s", |
| 208 | + small[value/100], big[tu/10]); |
| 209 | + else if (tu < 20) |
| 210 | + sprintf(buf, "%s hundred and %s", |
| 211 | + small[value/100], small[tu]); |
| 212 | + else |
| 213 | + sprintf(buf, "%s hundred %s %s", |
| 214 | + small[value/100], big[tu/10], small[tu % 10]); |
| 215 | + } |
| 216 | + else |
| 217 | + { |
| 218 | + /* is it an even multiple of 10 other than 10? */ |
| 219 | + if (value % 10 == 0 && tu > 10) |
| 220 | + sprintf(buf, "%s", big[tu/10]); |
| 221 | + else if (tu < 20) |
| 222 | + sprintf(buf, "%s", small[tu]); |
| 223 | + else |
| 224 | + sprintf(buf, "%s %s", big[tu/10], small[tu % 10]); |
| 225 | + } |
| 226 | + |
| 227 | + return(buf); |
| 228 | +} |
| 229 | + |
| 230 | +/* this converts a long as well but to a representation using words */ |
| 231 | +/* obviously way North American centric - sorry */ |
| 232 | +const char * |
| 233 | +cash_words_out(long value) |
| 234 | +{ |
| 235 | + static char buf[128]; |
| 236 | + char *p = buf; |
| 237 | + long m0; |
| 238 | + long m1; |
| 239 | + long m2; |
| 240 | + long m3; |
| 241 | + |
| 242 | + /* work with positive numbers */ |
| 243 | + if (value < 0) |
| 244 | + { |
| 245 | + value *= -1; |
| 246 | + strcpy(buf, "minus "); |
| 247 | + p += 6; |
| 248 | + } |
| 249 | + else |
| 250 | + *buf = 0; |
| 251 | + |
| 252 | + m0 = value % 100; /* cents */ |
| 253 | + m1 = (value/100) % 1000; /* hundreds */ |
| 254 | + m2 = (value/100000) % 1000; /* thousands */ |
| 255 | + m3 = value/100000000 % 1000; /* millions */ |
| 256 | + |
| 257 | + if (m3) |
| 258 | + { |
| 259 | + strcat(buf, num_word(m3)); |
| 260 | + strcat(buf, " million "); |
| 261 | + } |
| 262 | + |
| 263 | + if (m2) |
| 264 | + { |
| 265 | + strcat(buf, num_word(m2)); |
| 266 | + strcat(buf, " thousand "); |
| 267 | + } |
| 268 | + |
| 269 | + if (m1) |
| 270 | + strcat(buf, num_word(m1)); |
| 271 | + |
| 272 | + if (!*p) |
| 273 | + strcat(buf, "zero"); |
| 274 | + |
| 275 | + strcat(buf, (int)(value/100) == 1 ? " dollar and " : " dollars and "); |
| 276 | + strcat(buf, num_word(m0)); |
| 277 | + strcat(buf, m0 == 1 ? " cent" : " cents"); |
| 278 | + *buf = toupper(*buf); |
| 279 | + return(buf); |
| 280 | +} |
| 281 | + |
| 282 | +#include <stdlib.h> |
| 283 | + |
| 284 | +#ifdef TEST_MAIN |
| 285 | +int |
| 286 | +main(void) |
| 287 | +{ |
| 288 | + char p[64], *q; |
| 289 | + long v; /* the long value representing the amount */ |
| 290 | + int d; /* number of decimal places - default 2 */ |
| 291 | + |
| 292 | + while (fgets(p, sizeof(p), stdin) != NULL) |
| 293 | + { |
| 294 | + if ((q = strchr(p, '\n')) != NULL) |
| 295 | + *q = 0; |
| 296 | + |
| 297 | + for (q = p; *q && !isspace(*q); q++) |
| 298 | + ; |
| 299 | + |
| 300 | + v = cash_in(p); |
| 301 | + d = *q ? atoi(q) : 2; |
| 302 | + |
| 303 | + printf("%12.12s %10ld ", p, v); |
| 304 | + printf("%12s %s\n", cash_out(v), cash_words_out(v)); |
| 305 | + } |
| 306 | + |
| 307 | + return(0); |
| 308 | +} |
| 309 | +#endif /* TEST_MAIN */ |
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