summaryrefslogtreecommitdiffstats
path: root/contrib/ntp/libntp/atolfp.c
diff options
context:
space:
mode:
Diffstat (limited to 'contrib/ntp/libntp/atolfp.c')
-rw-r--r--contrib/ntp/libntp/atolfp.c118
1 files changed, 118 insertions, 0 deletions
diff --git a/contrib/ntp/libntp/atolfp.c b/contrib/ntp/libntp/atolfp.c
new file mode 100644
index 0000000..ff50947
--- /dev/null
+++ b/contrib/ntp/libntp/atolfp.c
@@ -0,0 +1,118 @@
+/*
+ * atolfp - convert an ascii string to an l_fp number
+ */
+#include <stdio.h>
+#include <ctype.h>
+
+#include "ntp_fp.h"
+#include "ntp_string.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";
+
+ 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((int)*cp))
+ cp++;
+
+ if (*cp == '-') {
+ cp++;
+ isneg = 1;
+ }
+
+ if (*cp == '+')
+ cp++;
+
+ if (*cp != '.' && !isdigit((int)*cp))
+ return 0;
+
+ while (*cp != '\0' && (ind = strchr(digits, *cp)) != NULL) {
+ dec_i = (dec_i << 3) + (dec_i << 1); /* multiply by 10 */
+ dec_i += (ind - digits);
+ cp++;
+ }
+
+ if (*cp != '\0' && !isspace((int)*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 += (ind - digits);
+ cp++;
+ }
+
+ while (isdigit((int)*cp))
+ cp++;
+
+ if (*cp != '\0' && !isspace((int)*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;
+}
OpenPOWER on IntegriCloud