Add implementation of strndup function and test for it

3 files changed, 49 insertions, 0 deletions

diff --git a/AUTHORS b/AUTHORS
index 1dd6039a..3d189c9f 100644
--- a/AUTHORS
+++ b/AUTHORS
@@ -22,3 +22,4 @@ under the licensing terms detailed in LICENSE.
 * Brian Anderson <banderson@mozilla.com>
 * Jon Bardin <diclophis@gmail.com>
 * Jukka Jylänki <jujjyl@gmail.com>
+* Aleksander Guryanov <caiiiycuk@gmail.com>
diff --git a/src/library.js b/src/library.js
index f406f02a..e49ea6da 100644
--- a/src/library.js
+++ b/src/library.js
@@ -4199,6 +4199,20 @@ LibraryManager.library = {
     return newStr;
   },
 
+  strndup__deps: ['strdup'],
+  strndup: function(ptr, size) {
+    var len = String_len(ptr);
+
+    if (size <= 0 || size >= len) {
+       return _strdup(ptr);
+    }
+    
+    var newStr = _malloc(0 + 1);
+    {{{ makeCopyValues('newStr', 'ptr', 'size', 'null', null, 1) }}};
+    {{{ makeSetValue('newStr', 'size', '0', 'i8') }}};
+    return newStr;
+  },
+
   strpbrk: function(ptr1, ptr2) {
     var searchSet = Runtime.set.apply(null, String_copy(ptr2));
     while ({{{ makeGetValue('ptr1', 0, 'i8') }}}) {
diff --git a/tests/runner.py b/tests/runner.py
index d6731ed5..4064af15 100755
--- a/tests/runner.py
+++ b/tests/runner.py
@@ -1393,6 +1393,40 @@ m_divisor is 1091269979
         '''
         self.do_run(src, '4:10,177,543,def\n4\nwowie\ntoo\n76\n5\n(null)\n/* a comment */\n// another\ntest\n', ['wowie', 'too', '74'])
 
+    def test_strndup(self):
+        src = '''
+          //---------------
+          //- http://pubs.opengroup.org/onlinepubs/9699919799/functions/strndup.html
+          //---------------
+
+          #include <stdio.h>
+          #include <stdlib.h>
+          #include <string.h>
+
+          int main(int argc, char **argv) {
+            const char* source = "strndup - duplicate a specific number of bytes from a string";
+
+            char* strdup_val = strndup(source, 7);
+            printf("%s\\n", strdup_val);
+            free(strdup_val);
+
+            strdup_val = strndup(source, 1000);
+            printf("%s\\n", strdup_val);
+            free(strdup_val);
+
+            strdup_val = strndup(source, 60);
+            printf("%s\\n", strdup_val);
+            free(strdup_val);
+
+            strdup_val = strndup(source, 19);
+            printf("%s\\n", strdup_val);
+            free(strdup_val);
+
+            return 0;
+          }
+        '''
+        self.do_run(src, 'strndup\nstrndup - duplicate a specific number of bytes from a string\nstrndup - duplicate a specific number of bytes from a string\nstrndup - duplicate\n')
+
     def test_errar(self):
         src = r'''
           #include <stdio.h>