Libc-498.tar.gz

[apple/libc.git] / stdlib / gcvt-obsd.c

diff --git a/stdlib/gcvt-obsd.c b/stdlib/gcvt-obsd.c
new file mode 100644 (file)
index 0000000..08b65fc
--- /dev/null
+++ b/stdlib/gcvt-obsd.c
@@ -0,0 +1,112 @@
+/*     $OpenBSD: gcvt.c,v 1.5 2003/06/17 21:56:24 millert Exp $        */
+
+/*
+ * Copyright (c) 2002, 2003 Todd C. Miller <Todd.Miller@courtesan.com>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ * Sponsored in part by the Defense Advanced Research Projects
+ * Agency (DARPA) and Air Force Research Laboratory, Air Force
+ * Materiel Command, USAF, under agreement number F39502-99-1-0512.
+ */
+
+#if defined(LIBC_SCCS) && !defined(lint)
+static char rcsid[] = "$OpenBSD: gcvt.c,v 1.5 2003/06/17 21:56:24 millert Exp $";
+#endif /* LIBC_SCCS and not lint */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <locale.h>
+
+extern char *__dtoa(double, int, int, int *, int *, char **);
+extern void __freedtoa(char *);
+
+char *
+gcvt(double value, int ndigit, char *buf)
+{
+       char *digits, *dst, *src;
+       int i, decpt, sign;
+       char *decimal_point = localeconv()->decimal_point;
+
+       if (ndigit == 0) {
+               buf[0] = '\0';
+               return (buf);
+       }
+
+       digits = __dtoa(value, 2, ndigit, &decpt, &sign, NULL);
+       if (decpt == 9999) {
+               /* Infinity or NaN, assume buffer is long enough. */
+               dst = buf;
+               if (sign)
+                       *dst++ = '-';
+               strcpy(dst, (*digits == 'N') ? "nan" : "inf");
+               __freedtoa(digits);
+               return (buf);
+       }
+
+       dst = buf;
+       if (sign)
+               *dst++ = '-';
+
+       if (decpt < 0 || decpt > ndigit) {
+               /* exponential format */
+               if (--decpt < 0) {
+                       sign = 1;
+                       decpt = -decpt;
+               } else
+                       sign = 0;
+               src = digits;
+               *dst++ = *src++;
+               dst = stpcpy(dst, decimal_point);
+               while (*src != '\0')
+                       *dst++ = *src++;
+               *dst++ = 'e';
+               if (sign)
+                       *dst++ = '-';
+               else
+                       *dst++ = '+';
+               if (decpt < 10) {
+                       *dst++ = '0';
+                       *dst++ = '0' + decpt;
+                       *dst = '\0';
+               } else {
+                       /* XXX - optimize */
+                       for (sign = decpt, i = 0; (sign /= 10) != 0; i++) {}
+                       dst[i + 1] = '\0';
+                       while (decpt != 0) {
+                               dst[i--] = '0' + decpt % 10;
+                               decpt /= 10;
+                       }
+               }
+       } else {
+               /* standard format */
+               for (i = 0, src = digits; i < decpt; i++) {
+                       if (*src != '\0')
+                               *dst++ = *src++;
+                       else
+                               *dst++ = '0';
+               }
+               if (*src != '\0') {
+                       if (src == digits) /* need leading zero */
+                               *dst++ = '0';
+                       dst = stpcpy(dst, decimal_point);
+                       for (i = decpt; digits[i] != '\0'; i++) {
+                               *dst++ = digits[i];
+                       }
+               }
+               *dst = '\0';
+       }
+       __freedtoa(digits);
+       return (buf);
+}