Add helpers for inputting and demonstrating floats.

ccan/opt/helpers.c

@@ -69,6 +69,19 @@ char *opt_set_intval(const char *arg, int *i)
 	return err;
 }
 
+char *opt_set_floatval(const char *arg, float *f)
+{
+	char *endp;
+
+	errno = 0;
+	*f = strtof(arg, &endp);
+	if (*endp || !arg[0])
+		return arg_bad("'%s' is not a number", arg);
+	if (errno)
+		return arg_bad("'%s' is out of range", arg);
+	return NULL;
+}
+
 char *opt_set_uintval(const char *arg, unsigned int *ui)
 {
 	int i;
@@ -159,6 +172,11 @@ void opt_show_intval(char buf[OPT_SHOW_LEN], const int *i)
 	snprintf(buf, OPT_SHOW_LEN, "%i", *i);
 }
 
+void opt_show_floatval(char buf[OPT_SHOW_LEN], const float *f)
+{
+	snprintf(buf, OPT_SHOW_LEN, "%.1f", *f);
+}
+
 void opt_show_uintval(char buf[OPT_SHOW_LEN], const unsigned int *ui)
 {
 	snprintf(buf, OPT_SHOW_LEN, "%u", *ui);

ccan/opt/opt.h

@@ -272,6 +272,8 @@ void opt_show_charp(char buf[OPT_SHOW_LEN], char *const *p);
 /* Set an integer value, various forms.  Sets to 1 on arg == NULL. */
 char *opt_set_intval(const char *arg, int *i);
 void opt_show_intval(char buf[OPT_SHOW_LEN], const int *i);
+char *opt_set_floatval(const char *arg, float *f);
+void opt_show_floatval(char buf[OPT_SHOW_LEN], const float *f);
 char *opt_set_uintval(const char *arg, unsigned int *ui);
 void opt_show_uintval(char buf[OPT_SHOW_LEN], const unsigned int *ui);
 char *opt_set_longval(const char *arg, long *l);