snippets for C string funcs

1 files changed, 35 insertions, 2 deletions

diff --git a/src/snippets.js b/src/snippets.js
index a93fd0fd..83cc26e6 100644
--- a/src/snippets.js
+++ b/src/snippets.js
@@ -17,12 +17,45 @@ var Snippets = {
   },
 
   strspn: function(pstr, pset) {
-    var str = String_copy(pstr);
+    var str = String_copy(pstr, true);
     var set = String_copy(pset);
     var i = 0;
-    while (set.indexOf(str[i]) != -1) i++; // Must halt, as 0 is in both
+    while (set.indexOf(str[i]) != -1) i++; // Must halt, as 0 is in str but not set
     return i;
   },
+
+  strcspn: function(pstr, pset) {
+    var str = String_copy(pstr, true);
+    var set = String_copy(pset, true);
+    var i = 0;
+    while (set.indexOf(str[i]) == -1) i++; // Must halt, as 0 is in both
+    return i;
+  },
+
+  strncpy: function(pdest, psrc, num) {
+    var padding = false;
+    for (var i = 0; i < num; i++) {
+      HEAP[pdest+i] = padding ? 0 : HEAP[psrc+i];
+      padding = padding || HEAP[psrc+i] == 0;
+    }
+  },
+
+  strcmp: function(px, py) {
+    var i = 0;
+    while (true) {
+      var x = HEAP[px+i];
+      var y = HEAP[py+i];
+      if (x == y && x == 0) return 0;
+      if (x == 0) return -1;
+      if (y == 0) return 1;
+      if (x == y) {
+        i ++;
+        continue;
+      } else {
+        return x > y ? 1 : -1;
+      }
+    }
+  },
 };
 
 // Aliases