--- /dev/null
+/*
+cash.c
+Written by D'Arcy J.M. Cain
+
+Functions to allow input and output of money normally but store
+and handle it as longs
+
+Set tabstops to 4 for best results
+
+A slightly modified version of this file and a discussion of the
+workings can be found in the book "Software Solutions in C" by
+Dale Schumacher, Academic Press, ISBN: 0-12-632360-7.
+
+*/
+
+#include <stdio.h>
+#include <string.h>
+#include <limits.h>
+#include <ctype.h>
+#include <locale.h>
+
+#ifdef TEST_MAIN
+# include <stdlib.h>
+# define palloc malloc
+#else
+# include <palloc.h>
+#endif
+
+#include "cash.h"
+
+/* when we go to 64 bit values we will have to modify this */
+#define CASH_BUFSZ 24
+
+#define TERMINATOR (CASH_BUFSZ - 1)
+#define LAST_PAREN (TERMINATOR - 1)
+#define LAST_DIGIT (LAST_PAREN - 1)
+
+/* function to convert a long to a dollars and cents representation */
+const char *
+cash_out(long value)
+{
+ char *retbuf, buf[CASH_BUFSZ];
+ struct lconv *lc = localeconv();
+ int mod_group = *lc->mon_grouping;
+ int comma = *lc->mon_thousands_sep;
+ int points = lc->frac_digits; /* int_frac_digits? */
+ int minus = 0;
+ int count = LAST_DIGIT;
+ int point_pos;
+ int comma_position = 0;
+
+ /* frac_digits in the C locale seems to return CHAR_MAX */
+ /* best guess is 2 in this case I think */
+ if (points == CHAR_MAX)
+ points = 2;
+
+ point_pos = LAST_DIGIT - points;
+
+ /* We're playing a little fast and loose with this. Shoot me. */
+ if (!mod_group || mod_group == CHAR_MAX)
+ mod_group = 3;
+
+ /* allow more than three decimal points and separate them */
+ if (comma)
+ {
+ point_pos -= (points - 1)/mod_group;
+ comma_position = point_pos % (mod_group + 1);
+ }
+
+ /* we work with positive amounts and add the minus sign at the end */
+ if (value < 0)
+ {
+ minus = 1;
+ value *= -1;
+ }
+
+ /* allow for trailing negative strings */
+ memset(buf, ' ', CASH_BUFSZ);
+ buf[TERMINATOR] = buf[LAST_PAREN] = 0;
+
+ while (value || count > (point_pos - 2))
+ {
+ if (points && count == point_pos)
+ buf[count--] = *lc->decimal_point;
+ else if (comma && count % (mod_group + 1) == comma_position)
+ buf[count--] = comma;
+
+ buf[count--] = (value % 10) + '0';
+ value /= 10;
+ }
+
+ if (buf[LAST_DIGIT] == ',')
+ buf[LAST_DIGIT] = buf[LAST_PAREN];
+
+ /* see if we need to signify negative amount */
+ if (minus)
+ {
+ retbuf = palloc(CASH_BUFSZ + 2 - count + strlen(lc->negative_sign));
+
+ /* Position code of 0 means use parens */
+ if (!lc->n_sign_posn)
+ sprintf(retbuf, "(%s)", buf + count);
+ else if (lc->n_sign_posn == 2)
+ sprintf(retbuf, "%s%s", buf + count, lc->negative_sign);
+ else
+ sprintf(retbuf, "%s%s", lc->negative_sign, buf + count);
+ }
+ else
+ {
+ retbuf = palloc(CASH_BUFSZ + 2 - count);
+ strcpy(retbuf, buf + count);
+ }
+
+ return retbuf;
+}
+
+/* convert a string to a long integer */
+long
+cash_in(const char *s)
+{
+ long value = 0;
+ long dec = 0;
+ long sgn = 1;
+ int seen_dot = 0;
+ struct lconv *lc = localeconv();
+ int fpoint = lc->frac_digits; /* int_frac_digits? */
+
+ /* we need to add all sorts of checking here. For now just */
+ /* strip all leading whitespace and any leading dollar sign */
+ while (isspace(*s) || *s == '$')
+ s++;
+
+ /* a leading minus or paren signifies a negative number */
+ /* again, better heuristics needed */
+ if (*s == '-' || *s == '(')
+ {
+ sgn = -1;
+ s++;
+ }
+ else if (*s == '+')
+ s++;
+
+ /* frac_digits in the C locale seems to return CHAR_MAX */
+ /* best guess is 2 in this case I think */
+ if (fpoint == CHAR_MAX)
+ fpoint = 2;
+
+ for (; ; s++)
+ {
+ /* we look for digits as long as we have less */
+ /* than the required number of decimal places */
+ if (isdigit(*s) && dec < fpoint)
+ {
+ value = (value * 10) + *s - '0';
+
+ if (seen_dot)
+ dec++;
+ }
+ else if (*s == *lc->decimal_point && !seen_dot)
+ seen_dot = 1;
+ else
+ {
+ /* round off */
+ if (isdigit(*s) && *s >= '5')
+ value++;
+
+ /* adjust for less than required decimal places */
+ for (; dec < fpoint; dec++)
+ value *= 10;
+
+ return(value * sgn);
+ }
+ }
+}
+
+
+/* used by cash_words_out() below */
+static const char *
+num_word(int value)
+{
+ static char buf[128];
+ static const char *small[] = {
+ "zero", "one", "two", "three", "four", "five", "six", "seven",
+ "eight", "nine", "ten", "eleven", "twelve", "thirteen", "fourteen",
+ "fifteen", "sixteen", "seventeen", "eighteen", "nineteen", "twenty",
+ "thirty", "fourty", "fifty", "sixty", "seventy", "eighty", "ninety"
+ };
+ const char **big = small + 18;
+ int tu = value % 100;
+
+ /* deal with the simple cases first */
+ if (value <= 20)
+ return(small[value]);
+
+ /* is it an even multiple of 100? */
+ if (!tu)
+ {
+ sprintf(buf, "%s hundred", small[value/100]);
+ return(buf);
+ }
+
+ /* more than 99? */
+ if (value > 99)
+ {
+ /* is it an even multiple of 10 other than 10? */
+ if (value % 10 == 0 && tu > 10)
+ sprintf(buf, "%s hundred %s",
+ small[value/100], big[tu/10]);
+ else if (tu < 20)
+ sprintf(buf, "%s hundred and %s",
+ small[value/100], small[tu]);
+ else
+ sprintf(buf, "%s hundred %s %s",
+ small[value/100], big[tu/10], small[tu % 10]);
+ }
+ else
+ {
+ /* is it an even multiple of 10 other than 10? */
+ if (value % 10 == 0 && tu > 10)
+ sprintf(buf, "%s", big[tu/10]);
+ else if (tu < 20)
+ sprintf(buf, "%s", small[tu]);
+ else
+ sprintf(buf, "%s %s", big[tu/10], small[tu % 10]);
+ }
+
+ return(buf);
+}
+
+/* this converts a long as well but to a representation using words */
+/* obviously way North American centric - sorry */
+const char *
+cash_words_out(long value)
+{
+ static char buf[128];
+ char *p = buf;
+ long m0;
+ long m1;
+ long m2;
+ long m3;
+
+ /* work with positive numbers */
+ if (value < 0)
+ {
+ value *= -1;
+ strcpy(buf, "minus ");
+ p += 6;
+ }
+ else
+ *buf = 0;
+
+ m0 = value % 100; /* cents */
+ m1 = (value/100) % 1000; /* hundreds */
+ m2 = (value/100000) % 1000; /* thousands */
+ m3 = value/100000000 % 1000; /* millions */
+
+ if (m3)
+ {
+ strcat(buf, num_word(m3));
+ strcat(buf, " million ");
+ }
+
+ if (m2)
+ {
+ strcat(buf, num_word(m2));
+ strcat(buf, " thousand ");
+ }
+
+ if (m1)
+ strcat(buf, num_word(m1));
+
+ if (!*p)
+ strcat(buf, "zero");
+
+ strcat(buf, (int)(value/100) == 1 ? " dollar and " : " dollars and ");
+ strcat(buf, num_word(m0));
+ strcat(buf, m0 == 1 ? " cent" : " cents");
+ *buf = toupper(*buf);
+ return(buf);
+}
+
+#include <stdlib.h>
+
+#ifdef TEST_MAIN
+int
+main(void)
+{
+ char p[64], *q;
+ long v; /* the long value representing the amount */
+ int d; /* number of decimal places - default 2 */
+
+ while (fgets(p, sizeof(p), stdin) != NULL)
+ {
+ if ((q = strchr(p, '\n')) != NULL)
+ *q = 0;
+
+ for (q = p; *q && !isspace(*q); q++)
+ ;
+
+ v = cash_in(p);
+ d = *q ? atoi(q) : 2;
+
+ printf("%12.12s %10ld ", p, v);
+ printf("%12s %s\n", cash_out(v), cash_words_out(v));
+ }
+
+ return(0);
+}
+#endif /* TEST_MAIN */
projects / thirdparty / postgresql.git / commitdiff
