X-Git-Url: https://wannabe.guru.org/gitweb/?a=blobdiff_plain;f=file_utils.py;h=f273ea4f9a5fe08da8c1f15e3108c65b7c33d0ea;hb=a4bf4d05230474ad14243d67ac7f8c938f670e58;hp=9fa8fd209264ec44378adff464904c8bc900b10d;hpb=eedcbd4f64af13ec2098508c3d839a60f7e9ffce;p=python_utils.git

diff --git a/file_utils.py b/file_utils.py
index 9fa8fd2..f273ea4 100644
--- a/file_utils.py
+++ b/file_utils.py
@@ -2,7 +2,6 @@
 
 """Utilities for working with files."""
 
-from dataclasses import dataclass
 import datetime
 import errno
 import hashlib
@@ -10,17 +9,49 @@ import logging
 import os
 import io
 import pathlib
+import re
 import time
 from typing import Optional
 import glob
 from os.path import isfile, join, exists
-from typing import List
+from typing import List, TextIO
 from uuid import uuid4
 
 
 logger = logging.getLogger(__name__)
 
 
+def remove_newlines(x):
+    return x.replace('\n', '')
+
+
+def strip_whitespace(x):
+    return x.strip()
+
+
+def remove_hash_comments(x):
+    return re.sub(r'#.*$', '', x)
+
+
+def slurp_file(
+    filename: str,
+    *,
+    skip_blank_lines=False,
+    line_transformers=[],
+):
+    ret = []
+    if not file_is_readable(filename):
+        raise Exception(f'{filename} can\'t be read.')
+    with open(filename) as rf:
+        for line in rf:
+            for transformation in line_transformers:
+                line = transformation(line)
+            if skip_blank_lines and line == '':
+                continue
+            ret.append(line)
+    return ret
+
+
 def remove(path: str) -> None:
     """Deletes a file.  Raises if path refers to a directory or a file
     that doesn't exist.
@@ -185,6 +216,18 @@ def does_file_exist(filename: str) -> bool:
     return os.path.exists(filename) and os.path.isfile(filename)
 
 
+def file_is_readable(filename: str) -> bool:
+    return does_file_exist(filename) and os.access(filename, os.R_OK)
+
+
+def file_is_writable(filename: str) -> bool:
+    return does_file_exist(filename) and os.access(filename, os.W_OK)
+
+
+def file_is_executable(filename: str) -> bool:
+    return does_file_exist(filename) and os.access(filename, os.X_OK)
+
+
 def does_directory_exist(dirname: str) -> bool:
     """Returns True if a file exists and is a directory.
 
@@ -289,11 +332,13 @@ def get_file_md5(filename: str) -> str:
 
 def set_file_raw_atime(filename: str, atime: float):
     mtime = get_file_raw_mtime(filename)
+    assert mtime
     os.utime(filename, (atime, mtime))
 
 
 def set_file_raw_mtime(filename: str, mtime: float):
     atime = get_file_raw_atime(filename)
+    assert atime
     os.utime(filename, (atime, mtime))
 
 
@@ -391,8 +436,8 @@ def describe_file_mtime(filename: str, *, brief=False) -> Optional[str]:
     return describe_file_timestamp(filename, lambda x: x.st_mtime, brief=brief)
 
 
-def touch_file(filename: str, *, mode: Optional[int] = 0o666) -> bool:
-    return pathlib.Path(filename, mode=mode).touch()
+def touch_file(filename: str, *, mode: Optional[int] = 0o666):
+    pathlib.Path(filename, mode=mode).touch()
 
 
 def expand_globs(in_filename: str):
@@ -427,14 +472,14 @@ class FileWriter(object):
         self.filename = filename
         uuid = uuid4()
         self.tempfile = f'{filename}-{uuid}.tmp'
-        self.handle = None
+        self.handle: Optional[TextIO] = None
 
-    def __enter__(self) -> io.TextIOWrapper:
+    def __enter__(self) -> TextIO:
         assert not does_path_exist(self.tempfile)
         self.handle = open(self.tempfile, mode="w")
         return self.handle
 
-    def __exit__(self, exc_type, exc_val, exc_tb) -> bool:
+    def __exit__(self, exc_type, exc_val, exc_tb) -> Optional[bool]:
         if self.handle is not None:
             self.handle.close()
             cmd = f'/bin/mv -f {self.tempfile} {self.filename}'