1 files changed, 40 insertions, 0 deletions
diff --git a/third_party/python/taskcluster_taskgraph/taskgraph/util/shell.py b/third_party/python/taskcluster_taskgraph/taskgraph/util/shell.py
new file mode 100644
index 0000000000..d695767f05
--- /dev/null
+++ b/third_party/python/taskcluster_taskgraph/taskgraph/util/shell.py
@@ -0,0 +1,40 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this file,
+# You can obtain one at http://mozilla.org/MPL/2.0/.
+
+import re
+
+SHELL_QUOTE_RE = re.compile(r"[\\\t\r\n \'\"#<>&|`(){}$;\*\?]")
+
+
+def _quote(s):
+    """Given a string, returns a version that can be used literally on a shell
+    command line, enclosing it with single quotes if necessary.
+
+    As a special case, if given an int, returns a string containing the int,
+    not enclosed in quotes.
+    """
+    if type(s) == int:
+        return "%d" % s
+
+    # Empty strings need to be quoted to have any significance
+    if s and not SHELL_QUOTE_RE.search(s) and not s.startswith("~"):
+        return s
+
+    # Single quoted strings can contain any characters unescaped except the
+    # single quote itself, which can't even be escaped, so the string needs to
+    # be closed, an escaped single quote added, and reopened.
+    t = type(s)
+    return t("'%s'") % s.replace(t("'"), t("'\\''"))
+
+
+def quote(*strings):
+    """Given one or more strings, returns a quoted string that can be used
+    literally on a shell command line.
+
+        >>> quote('a', 'b')
+        "a b"
+        >>> quote('a b', 'c')
+        "'a b' c"
+    """
+    return " ".join(_quote(s) for s in strings)