Adding strip function to remove leading and trailing whitespace from …

docs/query-guide/functions.rst

@@ -102,6 +102,14 @@ math, string manipulation or more sophisticated expressions to be expressed.
 
     Returns true if ``b`` is a substring of ``a``
 
+.. function:: strip(s[, leading, trailing])
+
+    :param: s: The string that will be stripped
+    :param: leading: strip whitespace from the beginning of ``s``. Default is ``True``.
+    :param: trailing: strip whitespace from the end of ``s``. Default is ``True``.
+
+    Returns a string with whitespace removed from the beginning and end of input string ``s``.
+
 .. function:: subtract(x, y)
 
     Returns ``x - y``

eql/functions.py

@@ -319,6 +319,29 @@ def run(cls, source, substring):
             return substring.lower() in source.lower()
         return False
 
+@register
+class Strip(FunctionSignature):
+    """Strip leading & trailing whitespace from a string."""
+
+    name = "strip"
+    argument_types = [STRING, BOOLEAN, BOOLEAN]
+    return_value = STRING
+    minimum_args = 1
+
+    @classmethod
+    def run(cls, source, leading=True, trailing=True):
+        """Strip whitespace from source."""
+
+        if not is_string(source):
+            return None
+
+        stripped = source
+        if leading:
+            stripped = stripped.lstrip()
+        if trailing:
+            stripped = stripped.rstrip()
+
+        return stripped
 
 @register
 class Substring(FunctionSignature):