Add support for HPSS (#22)

Adds classes to interface with the hsi and htar commands with several helper methods for easier use. Resolves #2.

docs/api.rst

@@ -8,5 +8,7 @@ API
   timetools
   jinja
   logger
+  hsi
+  htar
 
 

docs/hsi.rst

@@ -0,0 +1,4 @@
+.. currentmodule:: wxflow
+
+.. autoclass:: Hsi
+    :members:

docs/htar.rst

@@ -0,0 +1,4 @@
+.. currentmodule:: wxflow
+
+.. autoclass:: Htar
+    :members:

src/wxflow/__init__.py

@@ -7,7 +7,9 @@
 from .executable import CommandNotFoundError, Executable, ProcessError, which
 from .factory import Factory
 from .file_utils import FileHandler
-from .fsutils import chdir, cp, mkdir, mkdir_p, rm_p, rmdir
+from .fsutils import chdir, chgrp, cp, get_gid, mkdir, mkdir_p, rm_p, rmdir
+from .hsi import Hsi
+from .htar import Htar
 from .jinja import Jinja
 from .logger import Logger, logit
 from .sqlitedb import SQLiteDB, SQLiteDBError

src/wxflow/fsutils.py

@@ -1,9 +1,11 @@
 import contextlib
 import errno
+import grp
 import os
 import shutil
 
-__all__ = ['mkdir', 'mkdir_p', 'rmdir', 'chdir', 'rm_p', 'cp']
+__all__ = ['mkdir', 'mkdir_p', 'rmdir', 'chdir', 'rm_p', 'cp',
+           'get_gid', 'chgrp']
 
 
 def mkdir_p(path):
@@ -85,3 +87,21 @@ def cp(source: str, target: str) -> None:
         raise OSError(f"unable to copy {source} to {target}")
     except Exception as exc:
         raise Exception(exc)
+
+
+# Group ID number for a given group name
+def get_gid(group_name: str):
+    try:
+        group_id = grp.getgrnam(group_name).gr_gid
+    except KeyError:
+        raise KeyError(f"{group_name} is not a valid group name.")
+
+    return group_id
+
+
+# Change the group of a target file or directory
+def chgrp(group_name, target, recursive=False):
+    # TODO add recursive option
+    gid = get_gid(group_name)
+    uid = os.stat(target).st_uid
+    os.chown(target, uid, gid)