Show "err" on FP error, wait for CLR key.

1 files changed, 14 insertions, 0 deletions

diff --git a/input.c b/input.c
index ac706ae..82c1cd1 100644
--- a/input.c
+++ b/input.c
@@ -10,11 +10,13 @@
 #include <string.h>
 #include <stdlib.h>
 #include <unistd.h>
+#include <fenv.h>
 
 char pending_op = 0;
 int making_number = 0;
 int base = 10;
 int quiet = 0;
+int showing_err = 0;
 
 #define MAXIN 40
 
@@ -79,6 +81,12 @@ show_value()
   char commas[40], *cp, *dp;
   double v = value;
 
+  if(fetestexcept(FE_ALL_EXCEPT)) {
+    set_string("Err");
+    showing_err = 1;
+	 return;
+  }
+
   if (base == 2)
   {
     int q = (long long)v & 0xffffffffL;
@@ -226,10 +234,16 @@ key(char c)
   int v = c;
   /* printf("key_number 0x%x\n", v); */
 
+  feclearexcept(FE_ALL_EXCEPT);
+
+  if(showing_err && c != 27 && c != 'C')
+    return;
+
   switch (c)
   {
   case 27:
   case 'C':
+    showing_err = 0;
     making_number = 0;
     iptr = 0;
     pending_op = 0;