new robust getcwd

Author: oesteban

nipype/utils/misc.py

@@ -7,9 +7,11 @@
                         absolute_import)
 from builtins import next, str
 
+import os
 import sys
 import re
 from collections import Iterator
+from warnings import warn
 
 from distutils.version import LooseVersion
 
@@ -301,3 +303,25 @@ def dict_diff(dold, dnew, indent=0):
         diff.insert(diffkeys, "Some dictionary entries had differing values:")
 
     return textwrap_indent('\n'.join(diff), ' ' * indent)
+
+
+def rgetcwd(error=True):
+    """
+    Robust replacement for getcwd when folders get removed
+    If error==True, this is just an alias for os.getcwd()
+    """
+    if error:
+        return os.getcwd()
+
+    try:
+        cwd = os.getcwd()
+    except OSError as exc:
+        # Changing back to cwd is probably not necessary
+        # but this makes sure there's somewhere to change to.
+        cwd = os.getenv('PWD')
+        if cwd is None:
+            raise OSError((
+                exc.errno, 'Current directory does not exist anymore, '
+                'and nipype was not able to guess it from the environment'))
+        warn('Current folder does not exist, replacing with "%s" instead.' % cwd)
+    return cwd

nipype/utils/tests/test_misc.py

@@ -4,6 +4,8 @@
 from future import standard_library
 standard_library.install_aliases()
 
+import os
+from shutil import rmtree
 from builtins import next
 
 import pytest
@@ -60,3 +62,30 @@ def test_flatten():
 
     back = unflatten([], [])
     assert back == []
+
+
+def test_rgetcwd(monkeypatch, tmpdir):
+    from ..misc import rgetcwd
+    oldpath = tmpdir.strpath
+    tmpdir.mkdir("sub").chdir()
+    newpath = os.getcwd()
+
+    # Path still there
+    assert rgetcwd() == newpath
+
+    # Remove path
+    rmtree(newpath, ignore_errors=True)
+    with pytest.raises(OSError):
+        os.getcwd()
+
+    monkeypatch.setenv('PWD', oldpath)
+    assert rgetcwd(error=False) == oldpath
+
+    # Test when error should be raised
+    with pytest.raises(OSError):
+        rgetcwd()
+
+    # Deleted env variable
+    monkeypatch.delenv('PWD')
+    with pytest.raises(OSError):
+        rgetcwd(error=False)