original files of m241

components/ip_net2-6.9/ipntp/src/libntp/atolfp.c

@@ -0,0 +1,122 @@
+/*
+ * atolfp - convert an ascii string to an l_fp number
+ */
+#include <ipntp_config.h>
+#include <stdio.h>
+#include <ctype.h>
+
+#include "ntp_fp.h"
+#include "ntp_string.h"
+#include "ntp_assert.h"
+
+/*
+ * Powers of 10
+ */
+static u_long ten_to_the_n[10] = {
+	0,
+	10,
+	100,
+	1000,
+	10000,
+	100000,
+	1000000,
+	10000000,
+	100000000,
+	1000000000,
+};
+
+
+int
+atolfp(
+	const char *str,
+	l_fp *lfp
+	)
+{
+	register const char *cp;
+	register u_long dec_i;
+	register u_long dec_f;
+	char *ind;
+	int ndec;
+	int isneg;
+	static const char *digits = "0123456789";
+
+	REQUIRE(str != NULL);
+
+	isneg = 0;
+	dec_i = dec_f = 0;
+	ndec = 0;
+	cp = str;
+
+	/*
+	 * We understand numbers of the form:
+	 *
+	 * [spaces][-|+][digits][.][digits][spaces|\n|\0]
+	 */
+	while (isspace((unsigned char)*cp))
+	    cp++;
+	
+	if (*cp == '-') {
+		cp++;
+		isneg = 1;
+	}
+	
+	if (*cp == '+')
+	    cp++;
+
+	if (*cp != '.' && !isdigit((unsigned char)*cp))
+	    return 0;
+
+	while (*cp != '\0' && (ind = strchr(digits, *cp)) != NULL) {
+		dec_i = (dec_i << 3) + (dec_i << 1);	/* multiply by 10 */
+		dec_i += (u_long)(ind - digits);
+		cp++;
+	}
+
+	if (*cp != '\0' && !isspace((unsigned char)*cp)) {
+		if (*cp++ != '.')
+		    return 0;
+	
+		while (ndec < 9 && *cp != '\0'
+		       && (ind = strchr(digits, *cp)) != NULL) {
+			ndec++;
+			dec_f = (dec_f << 3) + (dec_f << 1);	/* *10 */
+			dec_f += (u_long)(ind - digits);
+			cp++;
+		}
+
+		while (isdigit((unsigned char)*cp))
+		    cp++;
+		
+		if (*cp != '\0' && !isspace((unsigned char)*cp))
+		    return 0;
+	}
+
+	if (ndec > 0) {
+		register u_long tmp;
+		register u_long bit;
+		register u_long ten_fact;
+
+		ten_fact = ten_to_the_n[ndec];
+
+		tmp = 0;
+		bit = 0x80000000;
+		while (bit != 0) {
+			dec_f <<= 1;
+			if (dec_f >= ten_fact) {
+				tmp |= bit;
+				dec_f -= ten_fact;
+			}
+			bit >>= 1;
+		}
+		if ((dec_f << 1) > ten_fact)
+		    tmp++;
+		dec_f = tmp;
+	}
+
+	if (isneg)
+	    M_NEG(dec_i, dec_f);
+	
+	lfp->l_ui = dec_i;
+	lfp->l_uf = dec_f;
+	return 1;
+}