Add ecvt(), fcvt() and gcvt() for standard compliance and legacy code.

1 files changed, 103 insertions, 0 deletions

diff --git a/lib/libc/stdlib/gcvt.c b/lib/libc/stdlib/gcvt.c
new file mode 100644
index 00000000000..c1a96b17a59
--- /dev/null
+++ b/lib/libc/stdlib/gcvt.c
@@ -0,0 +1,103 @@
+/*	$OpenBSD: gcvt.c,v 1.1 2002/12/02 15:38:54 millert Exp $	*/
+
+/*
+ * Copyright (c) 2002 Todd C. Miller <Todd.Miller@courtesan.com>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
+ * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
+ * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
+ * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+ * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
+ * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#if defined(LIBC_SCCS) && !defined(lint)
+static char rcsid[] = "$OpenBSD: gcvt.c,v 1.1 2002/12/02 15:38:54 millert Exp $";
+#endif /* LIBC_SCCS and not lint */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+extern char *__dtoa(double, int, int, int *, int *, char **);
+
+char *
+gcvt(double value, int ndigit, char *buf)
+{
+	char *digits, *dst, *src;
+	int i, decpt, sign;
+
+	if (ndigit == 0) {
+		buf[0] = '\0';
+		return (buf);
+	}
+
+	digits = __dtoa(value, 2, ndigit, &decpt, &sign, NULL);
+	if (decpt == 9999)
+		return (strcpy(buf, digits));
+
+	dst = buf;
+	if (sign)
+		*dst++ = '-';
+
+	if (decpt < 0 || decpt > ndigit) {
+		/* exponential format */
+		if (--decpt < 0) {
+			sign = 1;
+			decpt = -decpt;
+		} else
+			sign = 0;
+		for (src = digits; *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++)
+				sign /= 10;
+			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') {
+			*dst++ = '.';		/* XXX - locale-specific (LC_NUMERIC) */
+			for (i = decpt; digits[i] != '\0'; i++) {
+				*dst++ = digits[i];
+			}
+		}
+		*dst = '\0';
+	}
+	return (buf);
+}