1 files changed, 63 insertions, 0 deletions
diff --git a/tabsvsspaces/pathtype.py b/tabsvsspaces/pathtype.py
new file mode 100644
index 0000000..39128cc
--- /dev/null
+++ b/tabsvsspaces/pathtype.py
@@ -0,0 +1,63 @@
+# As usual: copied form stack overflow
+# https://stackoverflow.com/a/33181083
+
+from argparse import ArgumentTypeError as err
+import os
+
+
+class PathType(object):
+    def __init__(self, exists=True, type='file', dash_ok=True):
+        """exists:
+                True: a path that does exist
+                False: a path that does not exist, in a valid parent directory
+                None: don't care
+           type: file, dir, symlink, None, or a function returning True for valid paths
+                None: don't care
+           dash_ok: whether to allow "-" as stdin/stdout"""
+
+        assert exists in (True, False, None)
+        assert type in ('file', 'dir', 'symlink', None) or hasattr(type, '__call__')
+
+        self._exists = exists
+        self._type = type
+        self._dash_ok = dash_ok
+
+    def __call__(self, string):
+        if string == '-':
+            # the special argument "-" means sys.std{in,out}
+            if self._type == 'dir':
+                raise err('standard input/output (-) not allowed as directory path')
+            elif self._type == 'symlink':
+                raise err('standard input/output (-) not allowed as symlink path')
+            elif not self._dash_ok:
+                raise err('standard input/output (-) not allowed')
+        else:
+            e = os.path.exists(string)
+            if self._exists:
+                if not e:
+                    raise err("path does not exist: '%s'" % string)
+
+                if self._type is None:
+                    pass
+                elif self._type == 'file':
+                    if not os.path.isfile(string):
+                        raise err("path is not a file: '%s'" % string)
+                elif self._type == 'symlink':
+                    if not os.path.symlink(string):
+                        raise err("path is not a symlink: '%s'" % string)
+                elif self._type == 'dir':
+                    if not os.path.isdir(string):
+                        raise err("path is not a directory: '%s'" % string)
+                elif not self._type(string):
+                    raise err("path not valid: '%s'" % string)
+            else:
+                if not self._exists and e:
+                    raise err("path exists: '%s'" % string)
+
+                p = os.path.dirname(os.path.normpath(string)) or '.'
+                if not os.path.isdir(p):
+                    raise err("parent path is not a directory: '%s'" % p)
+                elif not os.path.exists(p):
+                    raise err("parent directory does not exist: '%s'" % p)
+
+        return string