1 files changed, 87 insertions, 0 deletions
diff --git a/pre_commit/languages/pygrep.py b/pre_commit/languages/pygrep.py
new file mode 100644
index 0000000..40adba0
--- /dev/null
+++ b/pre_commit/languages/pygrep.py
@@ -0,0 +1,87 @@
+import argparse
+import re
+import sys
+from typing import Optional
+from typing import Pattern
+from typing import Sequence
+from typing import Tuple
+
+from pre_commit import output
+from pre_commit.hook import Hook
+from pre_commit.languages import helpers
+from pre_commit.xargs import xargs
+
+ENVIRONMENT_DIR = None
+get_default_version = helpers.basic_get_default_version
+healthy = helpers.basic_healthy
+install_environment = helpers.no_install
+
+
+def _process_filename_by_line(pattern: Pattern[bytes], filename: str) -> int:
+    retv = 0
+    with open(filename, 'rb') as f:
+        for line_no, line in enumerate(f, start=1):
+            if pattern.search(line):
+                retv = 1
+                output.write(f'{filename}:{line_no}:')
+                output.write_line_b(line.rstrip(b'\r\n'))
+    return retv
+
+
+def _process_filename_at_once(pattern: Pattern[bytes], filename: str) -> int:
+    retv = 0
+    with open(filename, 'rb') as f:
+        contents = f.read()
+        match = pattern.search(contents)
+        if match:
+            retv = 1
+            line_no = contents[:match.start()].count(b'\n')
+            output.write(f'{filename}:{line_no + 1}:')
+
+            matched_lines = match[0].split(b'\n')
+            matched_lines[0] = contents.split(b'\n')[line_no]
+
+            output.write_line_b(b'\n'.join(matched_lines))
+    return retv
+
+
+def run_hook(
+        hook: Hook,
+        file_args: Sequence[str],
+        color: bool,
+) -> Tuple[int, bytes]:
+    exe = (sys.executable, '-m', __name__) + tuple(hook.args) + (hook.entry,)
+    return xargs(exe, file_args, color=color)
+
+
+def main(argv: Optional[Sequence[str]] = None) -> int:
+    parser = argparse.ArgumentParser(
+        description=(
+            'grep-like finder using python regexes.  Unlike grep, this tool '
+            'returns nonzero when it finds a match and zero otherwise.  The '
+            'idea here being that matches are "problems".'
+        ),
+    )
+    parser.add_argument('-i', '--ignore-case', action='store_true')
+    parser.add_argument('--multiline', action='store_true')
+    parser.add_argument('pattern', help='python regex pattern.')
+    parser.add_argument('filenames', nargs='*')
+    args = parser.parse_args(argv)
+
+    flags = re.IGNORECASE if args.ignore_case else 0
+    if args.multiline:
+        flags |= re.MULTILINE | re.DOTALL
+
+    pattern = re.compile(args.pattern.encode(), flags)
+
+    retv = 0
+    for filename in args.filenames:
+        if args.multiline:
+            retv |= _process_filename_at_once(pattern, filename)
+        else:
+            retv |= _process_filename_by_line(pattern, filename)
+    return retv
+
+
+if __name__ == '__main__':
+    exit(main())